METHOD AND MACHINE FOR TESTING

A FORMING PROCESS

The present invention relates to the technical field of manufacturing glass containers such as, for example, bottles, jars or flasks, using a forming installation comprising several distinct forming sections.

In known manner, a forming installation comprises several forming sections each comprising at least one blank mold and at least one finishing mold. This installation also includes a distributor of molten glass parisons or malleable glass drops falling by gravity into each blank mold. A parison of molten glass is first formed from a blank in the blank mold, then transferred for final shaping in the finishing mold. Each container extracted from the finishing mold at a temperature still of the order of 600 ° C. is conveyed to various treatment and control stations.

The quality control of glass containers is necessary in order to eliminate those which have defects liable to affect their aesthetic character or, more seriously, to constitute a real danger for the subsequent user.

A first quality criterion for glass containers relates to the distribution of the glass, that is to say the distribution of the thickness of the glass wall.

The distribution of glass in the manufactured containers depends on several control parameters of the forming process, such as the quality of the loading of the glass into the blank mold. Indeed, the centering of the glass drop with respect to the blank mold, the timing of arrival of the drop, its orientation / inclination when it enters the mold directly influence the distribution of glass in the containers produced. Other characteristics also influence this distribution, for example the lubrication and ventilation of the molds, the temperature distribution in the drop, the deformations of the drop during dispensing.

Furthermore, the molds and in particular the finishing mold determine the shape of the containers, more precisely its exterior surface. The shaping of the glass drop determines the quantity of glass constituting the container. However, the internal surface of the container is produced by piercing or blowing the drop of glass loaded into the blank mold, then the blank obtained is blown into the finishing mold. Also the internal surface depends on many process control parameters, and the thickness can vary according to these parameters in different places of the final container. For example, the vertical wall of the body may have thicker or thinner regions, part of the bottom may be thicker, for example the interior of the bottom may be sloping or trapezoidal instead of being flat. It is possible that the part of the shoulder corresponding to the right half-mold is thicker than the opposite part. In another situation, the thickness of the lower body may increase at the expense of the upper body. It also happens that thin areas below a determined threshold appear at the heel or shoulder of the container.

Abnormal distribution of the glass is a manufacturing defect that must be corrected. It should be considered that it appears advantageous to identify a forming defect as early as possible on leaving the forming installation so as to correct it as soon as possible at this installation. In the state of the art, various solutions have been proposed for controlling the distribution of glass in the high-temperature containers leaving the forming machine.

A simple but imprecise method is manual observation by operators who section a container and observe the wall thickness at the section. Optionally, a caliper, a feeler or a jig can give a measurement value. This destructive method, used sparingly, gives an imprecise measurement limited to the location of the cut.

Manual glass thickness sensors exist. For example, manual hall effect sensors measure the distance between an inner ball and a sensor in contact with the outer face. They are precise but

only manuals and i! takes a long time to obtain a distribution of glass over the entire container. Moreover, this measurement does not make it possible to guide the operators in the control of the forming process.

Another method is the observation of the hot containers moving on the exit conveyor, by an infrared camera, assuming that the thick regions of the containers radiate more. Consequently, the analysis of the infrared images of the containers in different parts, probably reflects heterogeneous distributions of glass. However, since temperature distribution faults also cause radiation heterogeneities, neither the operator nor the inspection machine has any real information on the distribution of the glass. In addition, regions are hidden from the camera, even if two cameras are used.

Another quality criterion for glass containers concerns the nominal or total capacity of the containers.

The capacity or holding capacity of a container is the minimum volume of liquid it contains if it is filled to the brim or to a specified height below the surface of the container ring. Regulatory or administrative provisions require precise knowledge of the capacity of the receptacles. The actual capacity of the receptacles must correspond to the capacity indicated on the receptacle, which is for example engraved on the receptacle or written on a label attached to the receptacle

Certain variations in the container manufacturing process can lead to variations in their capacity. At constant glass volume, if the volume of the finishing mold increases by wear, the internal volume of the container increases. At constant mold volume, if the volume of glass increases, the capacity of the container decreases. Likewise, variations in shape (height, ovalization of the body, etc.) may have an influence on the capacity of the receptacles. To measure the volume characteristics of the molds, patent FR 2 717 574 teaches a method and a device for gauging the interior volume of a glassmaking mold.

To measure the capacity of the receptacles, it is known for example a machine marketed by the company AGR international, Inc, (http://www.aQrinti.com/Droducts/view/10/Fili-HeiQht-Tester '). based on the principle of weighing. This machine comprises a weighing plate on which rests the empty container resting by its bottom, in static equilibrium by gravity on a horizontal laying plane. This container is then filled with a liquid of known density up to a nominal level considered with respect to the bearing plane delimited by the weighing plate. Filling the container to the nominal level is achieved by filling the container above the nominal level and removing the excess volume with a pipette resting on the surface of the container ring so that the orifice of the pipette is located. at the nominal level in relation to the support plane. This machine performs by weighing, at a known temperature, the measurement of the quantity of liquid actually contained in the

A disadvantage of this machine concerns the time to carry out this measurement. In addition, this machine has the drawback of not being able to perform other dimensional measurements except for the empty weight of the container. This machine thus complements automatic dimensional control devices, of the optical type or by mechanical probes. , which do not allow the capacity of the receptacles to be measured.

It is also known from document US 2014/211980 a method and an X-ray apparatus for measuring the volume of a liquid partially filling a bottle, in particular by detecting the surface of the liquid inside the bottle. If this method makes it possible to measure the volume of a liquid inside a bottle, this technique does not make it possible to measure the real capacity of a bottle on the one hand, and according to the standardized measurement conditions on the other go.

Patent application US 2010/303287 describes an X-ray apparatus suitable for determining whether an object contains a liquid. If such a document makes it possible to measure the volume of liquid contained inside a bottle, the technique described by this document has the same drawbacks as your patent application US 2014/211980. In the same sense, patent application WO 2013/185816 describes a method and an X-ray system for detecting defects in containers or in their contents. This method does not allow the actual capacity of a cylinder to be measured under standard measurement conditions. In addition, these techniques do not make it possible to guide the operators in controlling the forming process implemented by the forming installation.

Another quality criterion of glass containers concerns the rendering of reliefs arranged on the containers either for aesthetic functions such as coats of arms or decorative engravings or for technical functions (text, code or other inscription of capacity, mold number , lot number, brand, model) or either for mechanical functions such as the counter ring or cap thread, positioning lug or notch, bottom contact ridges, label guard.

Rendering reliefs is the fact that relief relative to an average smooth surface or background is sufficient:

• or for human reading (aesthetic appearance or reading of important information);

• or for automatic reading (case of mold numbers coded in the form of dots or beads);

• or for mechanical use as a notch for orientation of the container.

The rendering of reliefs depends on several parameters:

• mold wear, ie the drop in the positive or negative level of a mold cavity;

• fouling of a mold cavity, by dirt obstructing the mold cavity preventing entry of the glass into the cavity;

• the thermal of the glass, which if it is too cold at the location of the impression, is too viscous to penetrate into the impression;

• the obstruction of the vents used to let the air caught between the indentation and the glass escape, or the insufficient vacuum when the vents require their connection to the vacuum.

The estimate of the rendering of the reliefs, which is always very partial, is often visual and subjective. At most, the rare measurements are made manually or with an optical microscope, or with probes by the quality services. These measurements are too late to be used for controlling the forming process. Most of the time, there is no standardized relief rendering measurement principle.

Another quality criterion of glass containers relates to the internal geometry of the neck. In fact, particularly according to the blow-blow process, the internal surface of the neck is not formed by a mold but by air under pressure.

The technical constraints on the neck are strong because of the future use of the containers. Thus, the possibility of introducing a filling cannula will be guaranteed if a minimum diameter is respected over the height of the neck. In reality, the neck must be able to contain a straight solid cylinder of sufficient diameter. This check is called "pinout".

The diameter at or just below the ring surface is called the "opening diameter". The inside diameter of a cylinder is commonly measured over a given depth under the ring surface, for example 5 mm, the diameter of which must be within a tolerance interval over said depth. This is necessary when the container is intended to be closed by a stopper forming the seal by its contact with the internal surface of the top of the neck.

When the container is intended to be closed by a resilient stopper, for example made of cork, then over the entire height of the stopper in place, for example over 50 mm, the diameters must have a given profile called “internal profile” or “unblocking profile”. Which is a function relating the internal diameter to the depth.

The state of the art has proposed various technical solutions for carrying out such inspections. For example, patent GB 1 432 120 describes a device for inspecting containers comprising several control stations, one of which aims to control the dimensional conformity of the rings and the necks of the containers. This control post has a mobile crew

driven by a motorization system in a reciprocating movement relative to the frame of the device, in a direction of movement parallel to the axis of symmetry of the containers. This mobile unit is equipped with an external gauge for checking the outside of the ring of the receptacles and an internal gauge for checking the inside of the ring and the neck of the receptacles.

A drawback of such a known device is the risk of a violent impact between the inspection head and the container, risking damage to the container or the gauge. Another disadvantage of this type of control is that it does not measure the diameters, but only checks the entry of a cylinder. It therefore does not allow measurement of the internal profile.

For current devices for measuring the internal profile on sample containers, it is necessary to introduce into the neck, articulated feelers, two in number in the opposite position, more rarely three at 120 °. The two feelers constitute two branches articulated in gripper. The lower ends of the clamp are brought into contact with the internal surface by a spring. Their spacing gives the internal diameter. The gripper and the container are then rotated relative to each other to have several diameters over 360 °, and the measurement can be repeated at other depths. The disadvantage of these probes is their slowness, their fragility, their wear, their lack of precision, because in particular it is never guaranteed that they measure diameters and not arcing chords. Moreover,

There are many other quality criteria for glass containers such as those relating to the functional dimensions of the container ring, the flatness of the surface of the container ring, the verticality of the containers, total or taken at the neck. or the body of containers, etc.

The external diameters and the ovality of the wall, the height of the container, the verticality of the body, the neck or overall of the container, the flatness of the rings, the internal diameters of the necks are measured using "multi-control" devices. ". It should be noted that these devices for measuring containers by sampling essentially use either mechanical feelers or optical detections. Contrary to what could

think those skilled in the art, the fact that the containers are made of transparent glass does not allow the internal surface to be easily measured by optical methods. This is the reason why the measurements of the internal diameters of the necks are carried out with mechanical feeler devices even when the other measurements are optical.

Analysis of the state of the art leads to the observation that the control of the quality of glass containers requires the use of multiple control or measurement devices. In addition, these control or measurement devices do not make it possible to obtain precise, repetitive and rapid measurements. Finally, these control or measurement devices are not able to provide sufficiently complete information to determine the corrections to be made to the control parameters of the installation for forming glass containers.

The present invention aims to remedy the drawbacks of the prior art by proposing a method for controlling the quality of glass containers, designed to carry out, using a single machine, precise, repetitive and rapid measurements and suitable for provide more complete information on the corrections to be made to the control parameters of a forming process for glass containers in a forming installation.

Another object of the invention is to provide a new method making it possible to control both the quality of the glass containers, both the distribution of the glass in these containers, as well as the capacity of these containers or the rendering of reliefs presented by various types of glass. such glass containers.

Another object of the invention is to provide a new method giving the possibility of always checking, by a single machine, numerous other quality criteria of glass containers.

Another object of the invention is to provide a method for controlling the quality of the containers, suitable for being implemented at any time during the container-forming process but advantageously earlier after their forming, the containers having d 'elsewhere still a high temperature.

To achieve such objectives, the method aims to control a glass container forming process implementing an installation with several distinct forming sections in each of which at least one parison of molten glass is first formed into a roughing in at least one blank mold, then secondly final shaping in at least one finishing mold.

According to the invention, the method comprises the following steps:

- take a container called a sample from an identified blank mold and an identified finishing mold;

- placing the sample container on a sample holder of a computer assisted X-ray tomography machine;

- acquire by means of the tomography apparatus, several radiographic images of the sample container under different projection angles;

- transmit the radiographic images to a computer;

- provide the computer with the position of the sample container in the finishing mold, in a mold mark;

- analyze the radiographic images by the computer to:

■ construct, in a virtual landmark, a three-dimensional digital model of the sample container from the radiographic images;

■ determine the position of the three-dimensional digital model with respect to the position of the sample container in the mold mark;

- And analyze the three-dimensional digital model to determine at least one quality indicator of the sample container by refation of at least one region of the sample container, making it possible to deduce therefrom an adjustment information for at least one control parameter of the process. forming in relation to the mold of the sample container.

In addition, the method according to the invention may further comprise in combination at least one and / or the other of the following additional characteristics:

- to determine the position of the three-dimensional digital model with respect to the position of the sample container in the mold mark, a io

method implemented by an operator consists in locating a marking relief on the sample container and placing the sample container on the sample holder so that its marking relief is positioned relative to a visual or mechanical identification device of the door -sample;

- to determine the position of the three-dimensional digital model with respect to the position of the sample container in the mold mark, another method consists of:

■ choose a marking height on the sample container whose position is known in the mold marker;

■ locate on the three-dimensional digital model, the virtual registration relief corresponding to the chosen registration relief;

■ and determine the position of the virtual locations in the virtual terrain reference to deduce the position of the three-dimensional digital model in the mold frame;

- according to an advantageous variant for building the three-dimensional digital model, the method consists in taking into account the sample holder so as to have a virtual vertical axis extending perpendicularly to the virtual plane of installation of the sample container on the holder -sample and to ensure a relative rotation around the virtual vertical axis, of the three-dimensional digital model in order to bring the virtual registration relief in a position corresponding to the position of the registration relief in the mold mark;

- it is advantageous to identify the blank mold and / or the finishing mold from which the sample container taken by a mold or location number comes from and to provide this mold number or this location number in relation the quality indicator of the sample container;

- to identify the blank mold and / or the finishing mold from which the sample container is taken, bearing a relief which indicates the mold or location number in the form of a code or alphanumeric, the method consists of:

■ ensure reading of the relief carried by the sample container and communicate the number read to the computer;

8 or to analyze the three-dimensional digital model of the sample container, by searching for the location of a virtual relief corresponding to the relief of the sample container, and to read this virtual relief so that it is made available to the computer;

- According to a preferred application, the sample container is taken at the latest before entering the annealing arch of the installation;

- Advantageously, the method consists in determining a quality indicator of the sample container, making it possible to deduce adjustment information for at least one control parameter of the container forming process for the identified molds, among:

■ the weight or shape of the glass parison loaded into the identified blank mold;

“ The position or speed of the glass parison when it is loaded into the Identified blank mold;

■ synchronization or speed or force in the movement of the mechanisms of the drilling punches, the identified molds, the transfers of the blank, the extraction clamps;

8 cooling of the identified molds or an associated punch;

“■ a blowing or pressing pressure for the identified molds;

8 replacement of an identified mold;

- According to an example of application, the method consists in determining, as a quality indicator of the sample container, the distribution of the glass of the sample container;

- According to another example of application, the method consists in determining, as a quality indicator of the sample container, at least one volume measurement of the sample container taken from, the capacity of the sample container, the volume of the casing of the sample container and the glass volume of the sample container;

- According to another example of application, the method consists in determining, as an indicator of the quality of the sample container, the rendering of reliefs arranged on the sample container;

- According to another example of application, the method consists in determining, as a quality indicator of the sample container, the internal geometry of the neck of the sample container;

- According to another example of application, the method consists in determining, as a quality indicator of the sample container, the flatness of the ring surface of the sample container;

- According to another example of application, the method consists in determining, as an indicator of the quality of the sample container, the outside diameters of the body of the sample container;

- for the determination of the distribution of glass as an indicator of the quality of the sample container, the method consists in determining the position of the center of mass of the three-dimensional digital model or of a portion of said model, and by comparing this position with a reference position;

- for the determination of the distribution of glass as an indicator of the quality of the sample container, the method consists in determining the thickness of the glass wall over at least one region of the sample container, by searching in this region for the position d 'a zone with a thickness greater than a predefined value and / or a thickness less than a predefined value, possibly by determining the extent of said zone, and / or by searching for the presence and the position of the place of the wall presenting the minimum or the maximum thickness in said region;

- for the determination of the distribution of glass as a quality indicator of the sample container, the method consists:

■ determining the volume of glass contained in at least two regions of three-dimensional digital model is divided by a vertical section plane containing the virtual vertical axis of three-dimensional digital model or either by a horizontal sectional plane perpendicular to said vertical virtual axis;

- and comparing said volumes with reference volume values ​​and / or between several regions of the same sample container, and / or between several sample containers;

- for the determination of the rendering of reliefs arranged on the sample container as an indicator of the quality of the sample container, the method consists of:

» Positioning at least one cutting plane on the three-dimensional digital model of the sample container so that it cuts at least part of a virtual relief of the external surface of said model;

* determine in the section plane, the curve representative of the section of the virtual relief;

■ superimposing at least partially on the representative curve, a zero altitude curve representing the curve of the external surface of the sample container devoid of said virtual relief;

* compare the representative curve with the zero altitude curve, by calculating as criterion for rendering the virtual relief at least one of the following quantities;

• a distance between the representative curve and the zero altitude curve;

• a slope deviation at a given position between the representative curve and the zero altitude curve;

• a variation in the slope of the representative curve;

• an area delimited by the representative curve and the zero altitude curve;

- for the determination of the rendering of reliefs arranged on the sample container as an indicator of the quality of the sample container, one variant consists of:

■ determining the representative surface terrain as an outer surface portion of the three-dimensional digital model in the area of interest containing at least a part of a virtual terrain;

■ superimposing at least partially on the external surface of the zone of interest, a surface of zero altitude representing the surface of the zone of interest devoid of said virtual relief;

■ compare the representative surface with the surface of zero altitude, by calculating as a criterion for rendering the relief at least one of the following quantities:

* a distance between the zero elevation surface and the representative surface;

* the slope deviation at a given position between the surface of zero altitude and the representative surface;

* a variation of the slopes of the representative surface;

* volumes delimited by the surface of zero altitude and the representative surface;

- for the determination of the rendering of reliefs arranged on the sample container as an indicator of the quality of the sample container, another variant consists of:

■ determine the representative surface of a virtual terrain such as an outer surface portion of the three-dimensional digital model in the area of interest containing at least one part of the relief at the corresponding virtual terrain sample container;

" Superimposing at least partially on the external surface of the zone of interest, a theoretical relief surface representing the surface of the zone of interest if the virtual relief is rendered correctly;

» Compare the representative surface with the theoretical surface, by calculating as a criterion for rendering the relief, at least one of the following quantities:

* a distance between the representative surface and the theoretical surface;

* a slope deviation at a given position between surfaces;

* volumes delimited by surfaces;

- for the determination of the rendering of reliefs arranged on the sample container as a quality indicator of the sample container, another variant consists of:

“ Select on the three-dimensional digital model, a virtual relief corresponding to a relief with a technical function whose position is known;

■ positioning a section plane so that it intersects said relief in a section plane corresponding to a design plane;

“ Obtain a curve representative of the section of the virtual relief;

■ measure on this representative curve, a radius of curvature and / or an angle, a length, a distance to a curve of zero altitude;

■ compare the measurement to predefined tolerance values.

- for the determination of the capacity of the sample container as a quality indicator of the sample container, the method consists of:

■ determine the internal surface of the three-dimensional digital model of the sample container;

■ determining a filling level plane on the three-dimensional digital model of the sample container, the filling level being either the virtual ring surface plane or a nominal filling level plane;

■ and measured by calculation, Se internal volume of the three-dimensional digital model of the sample defined by the inner surface of the container and the filling level plane, this measure being the ability of the sample container;

- for the determination of the volume of the envelope of the sample container as a quality indicator of the sample container, the method consists of:

» Determining the external surface of the three-dimensional digital model of the sample container;

" Determining a volume closure plane to be the ring surface plane or the bottom ring mold seal plane;"

» And measure by calculation the internal volume delimited by the external surface and the closure plane as being the volume of the envelope of the sample container;

- for the determination of the glass volume of the sample container as a quality indicator of the sample container, the method consists in determining the volume of the wall of the three-dimensional digital model of the sample container;

an advantageous variant consists in analyzing the three-dimensional digital model by looking for bubbles corresponding to material shortages between the internal surface and the external surface, and in measuring the volumes of said bubbles, which are then subtracted from the volume of the wall of the digital model three-dimensional, determined between the internal surface and the external surface, in order to obtain a volume corresponding to the volume of glass of the parison loaded into the identified blank mold from which the blank has been transferred into the finishing mold from which the sample container originates ;

- According to an advantageous application, the method consists of;

* consider as being a measurement of the volume of the parison loaded in the blank mold, the volume of glass of the three-dimensional digital model, with or without taking into account the material shortages;

- consider the internal volume delimited by the external surface of the three-dimensional digital model and a closure plane as being a measure of the internal volume of the finishing mold;

■ consider the volume delimited by the internal surface of the three-dimensional digital model and a fill level plane as a measure of the capacity of the sample container;

* deduce from the measurements of the capacity of the sample container and of the internal volume of the finishing mold, the volume of the parison to be loaded into the blank mold from which the sample container comes;

■ and decide when the capacity of the sample container is not compliant, to modify the weight of the parison for at least the mold

blank from which the sample container is taken or to replace the finishing mold;

- for the determination of the geometry of the neck of the sample container as an indicator of the quality of the sample container, the method consists of:

* determine on the three-dimensional digital model the internal surface corresponding at least to that of the neck;

» Positioning at least one cutting plane parallel to a virtual laying plane;

“ Measure in this plane several diameters of the internal surface and determine the minimum and / or the maximum in the section plane;

- Advantageously, the method aims to determine as an indicator of the geometry of the neck:

"the diameter at the opening;

■ and / or the broaching diameter;

■ and / or the internal profile of the sample container;

- for the determination of the flatness of the ring surface of the sample container as a quality indicator of the sample container, the method consists of:

“ Determining from the three-dimensional digital model, a closed three-dimensional curve or an annular surface representative of the ring surface;

■ positioning a ring surface reference plane in relation to the closed three-dimensional curve or the annular surface;

» And measuring the deviations between the reference plane and the closed three-dimensional curve or the annular surface;

- for the determination of the outside diameters of the body of the sample container as an indicator of the quality of the sample container, the method consists of:

was determined from the three-dimensional digital model, the outer surface corresponding to at least the portion of the sample container in which an outer diameter is to be measured;

» Positioning a cutting plane parallel to the virtual laying plane of the model according to at least one height of the container;

B measure several diameters in this section plane with respect to the external surface and compare these measurements to reference values.

Thus, the method according to the invention makes it possible to carry out, in addition to previously impossible measurements such as the distribution of the glass, or with separate devices (capacity control and gauging of the molds), all the measurements carried out by the glass metrology machines by prior art probes and / or optical sensors.

The invention also relates to a machine for controlling a method for forming glass containers using an installation with several distinct forming sections in each of which at least one parison of molten glass is first formed from a blank in the invention. at least one blank mold, then secondly final shaping in at least one finishing mold.

According to the invention, the machine comprises:

a computer-assisted X-ray tomography apparatus, capable of producing several radiographic images at different projection angles of a sample container placed on a sample holder of said apparatus;

a device for knowing the position of the sample container in the finishing mold, according to a mark on the mold;

- a computer connected to the device and to the tomography apparatus and configured to analyze the radiographic images for:

■ construct, in a virtual landmark, a three-dimensional digital model of the sample container from the radiographic images;

■ determine the position of the three-dimensional digital model with respect to the position of the sample container in the machine coordinate system;

■ analyze the three-dimensional digital model to determine at least one quality indicator of the sample container in relation to at least one region of the sample container, making it possible to deduce therefrom adjustment information for at least one control parameter of the forming process in relation to the mold of the sample container;

- and a system for delivering at least the quality indicator of the sample container in relation to at least one region of the sample container.

In addition, the machine according to the invention may further include in combination at least one and / or the other of the following additional characteristics:

- the system for delivering at least the quality indicator of the sample container in relation to at least one region of the sample container comprises a display system for the quality indicator in relation to the identity of the finishing mold;

the system for delivering at least the quality indicator of the sample container in relation to at least one region of the sample container comprises a connection for transmitting to a control system of the forming installation, the quality indicator in relation the identity of the finishing mold;

- a system providing the computer with the mold or location number of the sample container.

The invention also relates to an installation for forming glass containers comprising several distinct forming sections in each of which at least one parison of molten glass is first formed from a blank in at least one blank mold, then secondly. place final shaping in at least one finishing mold.

According to the invention, the installation comprises a machine in accordance with the invention placed at the outlet of the finishing molds.

Various other characteristics emerge from the description given below with reference to the appended drawings which show, by way of non-limiting examples, embodiments of the object of the invention.

Figure 1 is a schematic top view showing a control machine according to the invention positioned by way of example at the outlet of a container forming installation.

Figure 2 illustrates schematically, in side view along a transverse axis X, a molding installation known per se.

Figure 3 is a schematic top view showing the finishing molds being opened from forming glass containers.

Figure 4 is a schematic perspective view of an example of a three-dimensional digital model of a container obtained using a computer assisted tomography apparatus.

FIG. 4A is a plan view showing an example of an image of a code resulting from a modeling of a container.

Figure 5 is a schematic sectional elevation view of an example of a three-dimensional digital model of a container.

Figures 6 and 7 are top views of the three-dimensional digital model in two characteristic positions relative to a virtual landmark.

Figures 8 and 9 are sectional elevation views of the three-dimensional digital model showing the position of the center of mass relative to a center of mass.

FIG. 10 is a schematic sectional elevation view passing through the virtual vertical axis Zv of the three-dimensional digital model giving the distribution of the glass volumes Vr along the virtual vertical axis Zv.

Figure 11 is a schematic plan view passing through the virtual vertical axis Zv of the three-dimensional digital model giving the distribution of the glass volumes distributed in eight zones A to H.

Figure 12 is a schematic view of a container explaining the definition of the capacity of a container.

Figure 13A is a view of a three dimensional digital model of a container.

Figures 13B to 13D are sectional views taken along the lines CC of FIG. 13A and illustrating different rendering inspection methods for reliefs.

Figure 14 is a sectional view of a three-dimensional digital model showing the neck of a container and illustrating the method of checking the internal geometry of the neck of a container.

FIG. 14A is a curve representing the values ​​of the internal diameter Di of the neck along the vertical axis Zv of the virtual mark.

Figure 15 is a sectional view of a three dimensional digital model showing the neck of a container and illustrating the method of checking the flatness of the surface of the ring of a container.

Figure 16 is a perspective view of a three-dimensional digital model of a container and illustrating the method of checking the outer diameters of the body of a container.

As emerges more precisely from FIG. 1, the object of the invention relates to a machine 1 making it possible to control a method for forming transparent or translucent glass containers 2 manufactured by a manufacturing or forming installation 3 of all types known per se. On leaving the forming installation 3, the containers 2 such as for example bottles or glass flasks, have a high temperature typically between 300 ° C and 600 ° C.

In known manner, the containers 2 which have just been formed by the installation 3 are placed successively on an output conveyor 5 to form a line of containers. The containers 2 are transported in line by the conveyor 5 in a transfer direction F so as to convey them successively to different treatment stations and in particular an annealing arch 6, upstream of which is placed a surface treatment hood 7 constituting usually the first of the processing stations after forming.

Figs. 1 to 3 illustrate an embodiment of a forming installation 3 known per se and which will be described succinctly for

only allow an understanding of the operation of the machine I according to the invention in relation to the forming installation 3.

The installation 3 comprises several distinct forming sections 12 each comprising at least one blank mold 13 and at least one finishing mold 14. The installation 3 comprises a source 16 of malleable glass, therefore of hot glass, and a distributor 17 of parisons. of glass which distributes, by gravity, malleable glass parisons 18 to each blank mold 13. In known manner, the malleable glass source 16 is a reservoir supplied with molten glass, at the bottom of which is a bowl comprising one to four openings circulars. A height-regulated rotating tube controls the flow of glass over the cuvette, and a system of one to four back-and-forth plunger (s) extrudes the glass through the one to four openings of the bowl in order to deliver by gravity, malleable glass in the form of one to four strings in parallel. The malleable glass strings are definitively separated into independent drops by a scissor system 19 arranged at the outlet of the hot glass source 16 and which is actuated at regular intervals to cut the malleable glass from the source 16 into sections.

For installations comprising several (up to four) mold cavities per section, possibly several sections are delivered in parallel simultaneously. In the present description, parison 18 is called a drop or extruded section of malleable glass as fed by the scissor system 19. In English, the parison is, at this stage of a forming process, called a “gob”. The malleable glass, at the level of the cut by the scissor system 19, generally has a temperature above 900 ° C, for example between 1100 and 1300 ° C. This parison is generally a solid cylinder of malleable glass having a volume and a length defined by the adjustment of the source 16 cooperating with the section of the scissor system 19. Indeed, the diameter of the parisons is defined by that of the openings of the bowl. The flow is controlled both by the height of the tube which acts on the overall flow and by the movements of the one to four plungers, which allows the flow to be varied.

separately for each opening of the cuvette. The time interval between two actuations of the scissor system 19 determines the length of the parison. To summarize the length, weight and volume of each parison are determined by the parameters of the source 16 (the tube and the plungers) and the scissor system 19. The source 16 of malleable glass is arranged above the blank molds. 13 to allow the distribution by gravity of the parisons which are loaded through openings 22 made in the upper faces of the blank molds 13.

The distributor 17 extends in several branches between the source 16 of hot glass and the blank molds 13 of each of the forming sections. Generally, the source 16 of hot glass, via the scissor system 19, simultaneously delivers as many parisons as there are blank molds (respectively finishing molds) in a forming section. It is therefore understood that the forming sections are supplied with parisons successively one after the other.

The distributor 17 therefore collects the parisons cut by the scissor system 19 and leads them to each of the blank molds 13 of each of the forming sections 12 along a corresponding loading path. The loading paths for the different blank molds 13 include common portions and specific portions. A specific portion is a portion of the loading path corresponding to a blank mold 13 which is followed only by the parisons which are directed by the distributor towards this blank mold.

The distributor 17 therefore comprises switching means which is a kind of chute or group of pivoting chutes, then guiding the parisons comprising chutes and deflectors at the end of their travel, above the blank molds. In particular, the position of the deflectors relative to the associated blank molds partly determines the position and orientation of the loading of each parison in said blank molds. In the distributor, the chutes, deflectors and switches determine the loading path of the parisons.

Glass container forming installations implement various processes combining successive filling, then pressing and / or blowing steps. For the clarity of the description, the example is taken of the forming of the containers according to the known methods called press-soufflé or blow-blow.

In container forming installations, each forming section 12 may include several molds, for example two molds, one of which is a blank mold 13 and the other is a finishing mold 14. Each section 12 may include a set of molds. blanks and a set of associated finishing molds. It is understood in this case, that a given parison is guided by the distributor 17 towards a blank mold, for example a blank mold 13 of the forming section where the parison undergoes a first forming operation, called drilling, carried out by blow molding. compressed air or by penetration of a punch. A transfer system (not shown) is then able to take the parison which has undergone the first forming operation, namely the blank, in the blank mold 13 for the take into a finishing mold 14 where the blank can undergo at least a second forming operation, the last so-called finishing operation. Generally, each blank or finisher mold of a forming section comprises two half-molds respectively 13a, 13b and 14a, 14b which are movable with respect to each other in a direction perpendicular to a parting plane P via which the two half-molds 13a, 13b and 14a, 14b are in contact in a closed position. In the example illustrated, the parting line P extends in the vertical direction Z and the transverse direction X. a forming section comprises two half-molds respectively 13a, 13b and 14a, 14b which are movable relative to each other in a direction perpendicular to a parting plane P through which the two half-molds 13a, 13b and 14a, 14b are in contact in a closed position. In the example illustrated, the joint plane P extends in the vertical direction Z and the transverse direction X. a forming section comprises two half-molds respectively 13a, 13b and 14a, 14b which are movable relative to each other in a direction perpendicular to a parting plane P through which the two half-molds 13a, 13b and 14a, 14b are in contact in a closed position. In the example illustrated, the joint plane P extends in the vertical direction Z and the transverse direction X.

A section 12 can include a single finishing mold 14 receiving a blank of a single blank mold 13. However, as mentioned above, each of the different forming sections 12 can include at least two distinct finishing molds 14 and as many blank molds 13. The Figures show the case of four forming sections 12 offset in a longitudinal direction Y perpendicular to the transverse direction X. According to this example, each forming section 12

comprises three blank molds 13 respectively front, central and rear (or external, central and internal) each associated with a finishing mold 14 respectively front, central and rear, that is to say each receiving the blank from a mold blank 13. In the illustrated example, the g

different blank molds 13 and respectively the finishing molds 14 of the same section are offset with respect to one another in a transverse direction X. In the example illustrated, the finishing molds 14 of the same section are of the shape identical, therefore generally intended to form identical containers, but one could provide different shapes and 0 different weights.

It should be noted that each finishing mold 14 is identified in the forming installation with respect to the other finishing molds 14. Likewise, each blank mold 13 is identified in the forming installation. It is thus possible to identify the forming section 12, the blank mold 5 13 and the finishing mold 14 from which each container 2 comes.

In an installation for forming glass containers, each blank mold location 13 of each section carries, according to different possible conventions, an identifier, for example a number or a letter. For example, the three locations for the second section of the installation shown in Fig, 1 can be identified by the letters a, b and c therefore forming the locations 2a, 2b, 2c to respectively designate the front, central and mold. rear of section number 2, these identifications will be called in the remainder of the description, “location numbers”.

Furthermore, the finishing molds of the bottom or of the body may bear an imprint in order to imprint in relief on the containers 2, the number of the mold for example between 1 and 99 or between 1 and 128, etc. A correspondence table between the location numbers and the mold numbers is permanently available for the operators or the installation information system. In some installations, a laser marker is used as described in patent EP 2 114 840 B1 in order to print

to each container still hot immediately after forming, a code indicating the mold number or the location number.

Thus, the receptacles generally bear either in a coded manner (bar code, point code, Datamatrix code) or in an alphanumeric manner, the indication of the mold number or the location number. In order to read these mold or location numbers carried by the containers, there are various optical reading systems for the production lines, such as those described in EP 1 010 126 or EP 2 297 672 or EP 2 992 315.

Thus, in the present description, it is understood that identifying the finishing mold from which a sample container comes therefore amounts to knowing either the location number or the mold number. It is understood that the identification of the finishing mold makes it possible to directly identify the associated blank mold providing the blank.

It also emerges from the above description that each blank mold 13 and each finishing mold 14 has a mold mark X, Y, Z making it possible to precisely locate each container in this mold mark (FIGS. 1 and 3). In other words, each manufactured container 2 can thus be located in this mold marker X, Y, Z of the blank mold 13 and of the finishing mold 14 from which each container 2 originates. The vertical axis Z is the axis of symmetry of the container passing through the axis of its neck while the transverse axis X is contained in the parting plane of the mold so that the plane XZ is called the parting plane P of the mold. The positive longitudinal axis Y is placed on the side of the right half shell of the mold for an observer O located in front of the

In forming installations, the control and synchronization of operations for forming parisons, chisel cutting, mold movements, punch movements, blowing, transfers, etc. are carried out by means of a control system 23 in the general sense, making it possible to control the various mechanisms necessary for the operation of the installation for the implementation of the container forming method.

In accordance with a characteristic of the control method according to the invention, a container 2 called a sample from a finishing mold 14 is taken at the outlet of this finishing mold 14. The sample container 2 is taken from all places of the various stations of treatment after forming. According to an advantageous implementation characteristic, the sample container 2 is taken at the latest before entering the annealing arch of the installation. In this case, the sample container 2 has a high temperature typically between 300 and 600 ° C. It should be noted that the finishing mold 14 from which this sample container came is identified as explained previously, that is to say that the forming section 12 to which this finishing mold 14 belongs is known as well as

This sample container 2 is intended to be inspected by the inspection machine 1 in accordance with the invention and more precisely by a computer-assisted X-ray tomography apparatus 30 forming part of this machine. Typically, this computer-assisted X-ray tomography apparatus 30 comprises a sample holder 31 on which the sample container 2 is deposited.

As emerges more precisely from FIG. 1, a computer-assisted tomography device 30 conventionally comprises, in an X-ray sealed enclosure, at least one source 32 for generating X-rays from its emission focus and at least one sensitive linear or matrix sensor 33 to X-rays. The sample holder 31 of the apparatus 30 serves as a mechanical laying plane Pp for the sample container 2 and is adapted to position between the source 32 and the sensor 33, the sample container 2 which is thus irradiated by X-rays. By absorption and diffusion, the material of the sample container 2 attenuates the X-rays which pass through it as a function of the atomic mass and the thickness of the material crossed. With sample container 2 empty,

receives the attenuated X-rays, and delivers an image of the attenuation caused only by the material of the container, i.e. an X-ray image I of the wall of the sample container 2.

The apparatus 30 also comprises a system 35 for creating a relative movement between the sample container 2 and the source torque 32 -sensor 33. Conventionally, this system 35 causes a displacement of known value of the sample container 2 relative to the source torque 32 - sensor 33, which remains fixed. Advantageously, this movement system 35 ensures the rotation of the sample container on itself about an axis of rotation which preferably but not necessarily coincides with the vertical axis of symmetry of the sample container.

The apparatus 30 also comprises a unit 36 ​​for controlling the source 32, the sensor 33 and the displacement system 35 allowing the operation of the apparatus and the obtaining of the radiographic images. Thus, this control unit 36 ​​ensures a known relative displacement of the sample container 2 with respect to the source 32 and to the sensor 33 so as to produce projections of the sample container at variable angles. The control unit 36 ​​ensures the acquisition during this movement of several radiographic images. Thus, the sample container 2 is moved between each acquisition of a radiographic image, so that each radiographic image is a projection of the sample container in directions different from each other.

It should be noted that the sensor 33 may have a height of field greater than the size of the sample container 2. The displacement system 35 is controlled to ensure the rotation of the sample container 2 on itself, typically over one revolution and the unit 36 ensures the acquisition of the various projections of the container over the 360 ​​° of rotation.

According to another variant embodiment, the sensor 12 may have a field height less than the size of the sample container 2. According to this example, the displacement system 35 is designed to ensure

also a relative vertical translational movement between the sample container 2 and the source 32 and / or the sensor 33 to scan the entire sample container 2.

For example, the displacement system 35 ensures the rotation of the sample container 2 on itself and a vertical translation of the sample container 2 with respect to the source 32-sensor 33 pair, which remains fixed. In the case where the sensor 33 is a linear horizontal field sensor, the unit 36 ​​controls the displacement system to position the sample container 2 so that the upper end of the sample container is positioned in the field of the sensor 33. L unit 36 ​​then controls the rotation of the sample container 2 on one turn and ensures the acquisition of the projections of the sample container on the sensor during this tour. The movement system 35 translates downwardly the sample container at an incremental step before the rotation of the sample container on itself and itself. acquisition of projections from the sample container. The displacement and acquisition steps are repeated until the lower end of the sample container 2 is positioned in the field of the sensor 33.

Alternatively in the case where the sensor 33 is a linear horizontal field sensor, the unit 36 ​​can control the displacement system to give the container a helical movement continuously combining the rotation around the axis and the translation along said axis, which allows the acquisition of a multitude of radiographic images or projections of the sample container 2.

A known computer-assisted tomography apparatus 30 as described above is marketed by the company RX SOLUTIONS under the trade name EasyTom.

Such a computer-assisted tomography apparatus 30 is connected to the computer 38 which has the radiographic images of the sample container 2 under different projection angles. The computer 38 is programmed to analyze the radiographic images in order to implement the control method in accordance with the invention.

It should be noted that the computer 38 is connected to a device 39 for knowing the position of the sample container 2 in the finishing mold 14 identified, according to the mold mark X, Y, Z, In other words, the computer 38 receives the information concerning the position of the sample container 2 in the identified finishing mold 14, according to the mold mark X, Y, Z.

The computer 38 is configured or programmed to analyze the radiographic images in order to construct, in a virtual frame Xv, Yv, Zv, a three-dimensional digital model M of the sample container 2 from the radiographic images (FIGS. 4 and 5). As the x-ray images are taken while the sample container 2 is empty, the x-ray images I show only the material of the sample container in contrast to air, the attenuation of which is negligible compared to that of the glass constituting the sample container. The three-dimensional digital model M thus has an external surface Se corresponding to the external surface of the sample container 2 and an internal surface Sf corresponding to the internal surface of the sample container 2.

The construction of the three-dimensional digital model M is carried out in any suitable manner known to those skilled in the art. Typically, the analysis of the radiographic images of the empty sample container 2 makes it possible to reconstruct a three-dimensional digital model of the sample container in the form of a set of “voxels”, that is to say of unit volumes whose value is l. absorption of the X-rays that they create, which therefore results in a volume distribution function very similar to a density distribution.

Making a three-dimensional digital model is the way - in mathematical, graphical and data structure terms - three-dimensional objects are represented and manipulated in computer memory. This three-dimensional digital model is analyzed to measure dimensions (lengths, areas, thicknesses, volumes). The three-dimensional digital model can remain solid or be transformed into a surface model, that is to say in which surfaces are modeled separating homogeneous volumes.

In surface models, an object is defined by its envelope, its boundary surfaces, which makes it possible to understand the interior / exterior notions, and the closed surfaces define volumes, to which a mass can be assigned for example as soon as we give a density of matter. Surfaces are modeled in several ways such as by polygonal modeling, by curves or parametric surfaces (cylinders, cones, spheres, splines, ...) or by subdivision of surfaces. Using a mesh of polyhedra, for example triangles, the surfaces of objects are represented by sets of plane facets connected by their edges.

A volume modeling consists in basing the representation on sets of identical elementary volumes called Voxels.

In order to operate length measurements there are several approaches.

In a first volume method, it is possible to travel through a volume model along a line or a bundle of lines and determine the material / air boundary voxels.

In a second surface method, it is possible to calculate a segment whose ends are the intersections of a line with the surface of a surface model. The algorithms solve topological problems quite well. The point is unique. Finally, a mixed method consists in transforming the solid model into a surface model, then in applying the second method.

In the present description, it should be understood that the correspondence between an element of the three-dimensional digital model M and an element of the sample container 2 means that the element of the three-dimensional digital model M is the virtual representation of the element of the sample container 2.

The computer 38 is configured or programmed to determine the position of the three-dimensional digital model M with respect to the position of the sample container 2 in the mold mark X, Y, Z. In other words, the three-dimensional digital model M corresponding to the sample container 2 is analyzed so as to be able to be located in a known position with respect to the position of the sample container 2 in the finishing mold. Thus, it is possible for any region of the three-dimensional digital model M, to know the position in the finishing mold, of the region of the sample container 2 corresponding to this region of the three-dimensional digital model M.

Of course, different methods of locating the three-dimensional digital model M can be implemented with respect to the position of the sample container in its identified finishing mold.

A first so-called manual solution can be envisaged consisting in considering a marking relief R on the sample container 2. on the containers either for aesthetic functions such as coats of arms or decorative engravings or for technical functions (text, code or other inscription of capacity, mold number, lot number, brand, model) or either for mechanical functions such as the backing ring or a plug thread, a positioning pin or notch, the bottom contact ridges, a label guard. In the example illustrated in FIG. 3,

The position of the marking relief R is known in the mold marking X,

Y, Z.

This sample container 2 is positioned on the sample holder 31 so that its locating relief R is positioned relative to a device for visual or mechanical locating of the sample holder 31. Thus, like the computer-assisted tomography apparatus 30 knows the position of the visual or mechanical locating device of the sample holder 31, the apparatus constructs the three-dimensional digital model M in a virtual frame of reference Xv, Yv, Zv, known with respect to the mold marker X, Y, Z. In d ' other words, relative to the actual position of the sample container on the sample holder, the three-dimensional digital model M of this container

sample is created making it possible to locate in particular the right part of the left part of this model corresponding respectively to the right and left parts of the sample container, separated by the mold parting line.

To ensure the identification of the three-dimensional digital model M, another so-called software solution can be envisaged consisting in choosing a marking relief R on the sample container 2 whose position is known in the mold reference X, Y, Z of the finishing mold which is from said sample container 2. The method then consists in locating on the three-dimensional digital model M, the relief corresponding to the registration relief R chosen on the sample container 2, and designated virtual registration relief Rv (FIG. 4). It is thus possible to determine the position of the virtual registration relief Rv in the virtual reference frame Xv, Yv, Zv, in order to deduce therefrom the position of the three-dimensional digital model M in the mold marker X, Y, Z of the identified finishing mold. Thus, for any region of the three-dimensional digital model M,

According to an advantageous variant embodiment, this locating method consists in constructing the three-dimensional digital model M by taking into account the sample holder 31 which serves as a mechanical laying plane Pp for the sample container 2. This method consists in positioning the digital model three-dimensional M of the container placed on its bottom, on a reference plane Pr of the virtual coordinate system considered as corresponding to the mechanical laying plane Pp, this reference plane Pr also being designated by a virtual laying plane in the remainder of the description.

According to an advantageous embodiment characteristic, the method consists in positioning the three-dimensional digital model M of the sample container on the reference plane or virtual laying plane Pr so that the three-dimensional digital model M of the sample container is placed in equilibrium. static on three points of its bottom in contact with the reference plane or virtual installation plane Pr. This technique takes into account the value of a density for the material constituting the container.

It can be chosen for this positioning to simulate gravity so that the three-dimensional digital model M of the sample container is raised in static equilibrium on three points of its bottom in contact with the reference plane or virtual landing plane Pr.

According to another advantageous variant embodiment, when the method aims to determine the capacity of the container, the method consists in positioning the three-dimensional digital model M of the sample container on the reference plane or virtual laying plane Pr so that by simulation gravity, the three-dimensional digital model of the container virtually filled to a level plane filled with a liquid of determined density, is standing in static equilibrium on three points of its bottom in contact with the reference plane or laying plane virtual Pr. This simulation method makes it possible to best approach the reality of a sample container filled with a liquid and resting on an installation plane.

It is thus possible, as appears from FIG. 5, to have a virtual vertical axis Zv extending perpendicularly relative to the virtual laying plane Pr of the sample container on the sample holder. As illustrated in Figs. 6 and 7, the method then consists in ensuring a relative rotation around the virtual vertical axis Zv, of the three-dimensional digital model M in order to bring the virtual registration relief Rv in a position corresponding to the position of the registration relief R in the mold mark on the finishing mold.

In the analysis of the three-dimensional digital model M, it advantageous, as explained previously, to determine the laying plane of the sample container and to use this plane as the base Xv, Yv of the virtual coordinate system.

Other markings are advantageous. For example we may have to define the vertex of the three-dimensional digital model M. This will be the point furthest from the pose plane. It is also possible to determine a surface plane of the ring Pb as:

• a plane passing through three points of the ring surface;

e or a mean plane of the ring surface;

<”Or a plane positioned in static equilibrium on the ring surface.

The method according to the invention then aims to analyze the three-dimensional digital model M to determine at least one quality indicator A of the sample container 2 in relation to at least one region of the sample container. In other words, the computer 38 is programmed to analyze the three-dimensional digital model M so as to determine at least one quality indicator A of the sample container 2 in relation to at least one region of the sample container from a finishing mold. identified. In accordance with the invention, the analysis leads to obtaining at least one quality indicator A of the sample container 2 making it possible to deduce therefrom an adjustment information for at least one control parameter of the forming process in relation of the identified mold of the sample container 2.

These control parameters relate to the control parameters of the forming process in relation in particular to the identified mold of the sample container 2. It is recalled that the blank mold 13 and / or the finishing mold 14 from which the sample container taken is identified are identified. by a mold number or a location number.

According to a preferred application, the method according to the invention aims to identify the blank mold 13 and / or the finishing mold 14 from which the sample container 2 originates by a mold number or by a location number and to update. layout, this mold number or this location number in relation to the quality indicator A of the sample container. Identifying the mold and providing the mold or location number can be accomplished in a number of ways.

In fully manual use, the operator takes a sample container 2 knowing its mold or location number. Once the computer 38 has delivered the value (s) of the quality indicator (s), the operator can act on the process according to the mold number or the location of the sample container.

In the other modes of use, the machine 1 according to the invention comprises a system 40 supplying the computer 38 with the mold or location number of the sample container 2. This system 40 provides the mold or location number according to the following various solutions, a) During the manual loading of the sample container on the sample holder 31, the system 40 is an input interface allowing the operator to enter the mold number or location of the sample container.

b) In case of automatic loading of a series of sample containers, an order is pre-established with the sequence of mold numbers or known successive sample container locations. This sequence of mold or sample container location numbers is provided by the system 40 to the computer 38. Alternatively, the member for taking and loading the sample containers or a computer supervision system, provided by the system 40, the numbers mold or location of each successive sample container.

c) Provision may be made to equip the machine 1 with a system 40 comprising an automatic reader 40a, for example optical, with a relief carried by the sample container and indicating the mold number, this system communicating the numbers to the computer 38. read and possibly the correspondence table with the location numbers.

d) Provision can also be made for the system 40 to supply the mold or location number to be produced by analysis means implemented by the computer 38 to analyze the three-dimensional digital model M of the sample container 2. This analysis aims to find on the three-dimensional digital model M, the location of a virtual relief Rn indicating the mold or location number and corresponding to the mold or location number carried by the sample container 2. In the example illustrated in FIG. 4, the three-dimensional digital model M of the sample container 2 comprises, as virtual relief Rn indicating the mold or location number, a series of imprints distributed spatially to form a code.

After having located this virtual relief Rn, the analysis means ensure the reading of this virtual relief Rn. According to a first method, the computer isolates said virtual relief from the background by subtracting a background surface matched by a “best fit” algorithm. It is possible to obtain as illustrated in FIG. 4A, a two-dimensional image le, in which the code appears in black on white or white on black contrast. To read this virtual relief according to a second method, the computer projects the thicknesses of the wall of the zone containing the virtual relief Rn to obtain an image of projected thickness. In this image of thickness le, which is a two-dimensional image in which the gray level represents the thickness of the projected glass, the code appears in black on white or white on black. From the two-dimensional images obtained, the code can then be analyzed and then read by an image processing algorithm known elsewhere, comprising for example the steps of segmentation and decoding or of OCR (Optical Character Recognition). The code corresponding to this virtual relief is made available to the computer 38.

The machine 1 according to the invention delivers the quality indicator (s) A from the sample container 2 in all possible exploitable forms. In this regard, the machine 1 according to the invention comprises a system 41 for delivering at least the quality indicator A of the sample container in relation to at least one region of the sample container. For example, the system 41 for delivering at least one quality indicator A of the sample container in relation to at least one region of the sample container comprises a display system 42 for the quality indicator in relation to at least one region of the sample container, this display being accompanied by the identity or identification of the finishing mold and / or the blank mold identified. From this quality indicator A,

According to another exemplary embodiment whether or not combined with the example described above, the system 41 for delivering at least one quality indicator of the sample container in relation to at least one region of the sample container comprises a connection 43 for transmitting to the sample container. control system 23 of the forming installation 3, the quality indicator A in relation to the identity of the finishing mold. This control system 23 can automatically or after validation take appropriate corrective measures I! It is thus possible to imagine setting up a correspondence table between the quality indicators A and the effects on the control parameters of the forming process of the forming installation 3.

In a nonlimiting manner, the quality indicator A of the sample container makes it possible to deduce adjustment information for at least one control parameter of the container forming process for the identified molds, among:

- the weight or shape of the glass parison loaded into the identified blank mold;

- the position or speed of the glass parison when it is loaded into the identified blank mold;

- synchronization or speed or force in the movement of the mechanisms of the piercing punches, of the identified molds, of the transfers of the blank, of the extraction clamps;

- cooling of the identified molds or of an associated punch;

- a blowing or pressing pressure for the identified molds;

- the replacement of an identified mold.

According to an advantageous characteristic of the invention, the method consists in determining, as quality indicator A of the sample container, at least one quality indicator taken from the following list, namely:

- the distribution of the glass of the sample container;

- the measurement of at least one volume of the sample container taken from the capacity of the sample container, Se volume of the envelope of the sample container, the volume of glass of the sample container and the volume of glass of the parison loaded into the blank mold identified from which the blank was transferred into the finishing mold from which the sample container 2 was taken;

- rendering of reliefs arranged on the sample container;

- the internal geometry of the neck of the sample container;

- the flatness of the surface of the ring of the sample container;

- the outside diameters of the body of the sample container.

The following description aims to describe the determination of the glass distribution as an indicator of quality A of the sample container. Of course, the glass distribution of the sample container 2 can be demonstrated according to various parameters or characteristics determined from the analysis of the three-dimensional digital model M.

Thus, the position of the center of mass is a characteristic of the glass distribution of the sample container 2.

The method according to the invention aims to determine the position of the center of mass Gv of the three-dimensional digital model M or of a portion of said model, and to compare this position with a reference position Gr of the center of mass.

For a container of revolution (for example with a generally conical or cylindrical body and without engraving), there is a center of mass theoretically centered horizontally on the axis of symmetry of the container. One method of verifying this property is to calculate the projection parallel to the vertical axis, on a section plane, of all the material in the container. The center of mass of this projection must be centered at the intersection of the vertical axis and the section plane.

If the container is not of simple revolution (general asymmetric shape, presence of engravings), it is possible to memorize a position of the reference center of mass learned for example by analyzing the three-dimensional digital model of a reference container whose glass distribution is correct.

Fig, 8 illustrates an exemplary embodiment in which the center of mass Gv of the three-dimensional digital model M in its entirety is projected into a plane Xv, Yv of the virtual frame of reference Xv, Yv, Zv, The position of the reference center of mass Gr of a reference container whose glass distribution is correct is calculated and projected into the plane Xv, Yv of the virtual reference frame Xv, Yv, Zv. If the centers of mass Gv and Gr are the same, then it can be concluded that the glass distribution of the sample container 2 is correct. In the example illustrated, the center of mass Gv of the three-dimensional digital model M is offset between the positive directions X and Y, that is to say towards the front of the right half-mold.

Fig. 9 illustrates an exemplary embodiment in which the position of the reference center of mass Gr of a reference container of which the glass distribution is correct is calculated and placed along the vertical axis Zv of the virtual reference frame Xv, Yv, Zv (for a revolution container for example). The center of mass Gv of the three-dimensional digital model M in its entirety is calculated and possibly projected onto the vertical axis Zv, of the virtual frame of reference Xv, Yv, Zv. If the centers of mass Gv and Gr are the same, then it can be concluded that the glass distribution of the sample container 2 is correct. In the example illustrated, the center of mass Gv of the three-dimensional digital model M is shifted downwards.

This information on the offset of the center of mass provides information for adjusting the control parameters of the forming process such as, for example, the speed of the parison, the moment of arrival of the parison, the lubrication of the molds, etc.

According to another example, the thickness of the glass wall is also a characteristic of the glass distribution of the sample container 2.

According to this example, the method according to the invention consists in determining the thickness of the glass wall on at least one region of the sample container, by searching for the position of a zone with a thickness greater than a predefined value and / or a thickness less than a predefined value, and / or by searching the different zones for the position and value of the minimum or maximum thicknesses. The method thus aims to

analyze the three-dimensional digital model M to measure the thickness between the external surface Se and the internal surface Sf over a region or all of this three-dimensional digital model M. These measurements are compared with minimum and maximum threshold values ​​making it possible to detect areas that are too thin or too thick and measure their extent. This method naturally makes it possible to obtain a map of the thickness of the sample container 2.

It is also possible:

- determine the volume of glass contained in at least two regions of the three-dimensional digital model M divided either by a vertical section plane containing the virtual vertical axis Zv of the three-dimensional digital model M or by at least one horizontal section plane perpendicular to said virtual vertical axis Zv;

- And to compare said volumes with reference volume values ​​and / or between several regions of the same sample container, and / or between several sample containers.

Fig. 10 illustrates an example of analysis of the three-dimensional digital model M making it possible to represent the distribution along the virtual vertical axis Zv of the volume Vr of glass taken along parallel slices perpendicular to the virtual vertical axis Zv. Of course, this distribution is compared to a distribution of volumes obtained from a three-dimensional digital model of a reference container.

Fig. 11 illustrates another example of analysis of the three-dimensional digital model M making it possible to represent the distribution of the volumes in a plane containing the virtual vertical axis Zv. According to this example, on either side of the virtual vertical axis Zv, the glass volumes located in four superimposed sections, namely AB, CD, E ~ F and GH, are shown. Each of these areas can be compared to reference volume values ​​or some of these areas can be compared to each other. Thus, the volumes of the CD zones can be compared to the volumes of the GH zones to assess the vertical distribution of the glass while a

global comparison or two by two of zones A, C, E and G with zones B, D, F and H makes it possible to assess the lateral distribution of the lens.

This information on the distribution of the thickness of the glass wall provides information for adjusting the control parameters of the forming process such as, for example, the loading conditions of the finishing mold (by acting for example on the position of the deflector), ventilation of the blank mold, lubrication, etc.

The following description aims to describe as a quality indicator A of the sample container, at least one volume measurement of the sample container 2 taken from, the capacity of the sample container, the volume of the shell of the sample container, the volume of glass of the sample container and the volume of glass of the parison loaded into the identified blank mold, which is recalled that this is the blank mold from which the blank was transferred into the identified finishing mold from which the container came sample 2.

Fig. 12 illustrates the definition of the capacity of the glass containers 2. A container 2 is a hollow object conventionally comprising a bottom 2a from which rises a body 2b extending by a neck 2c terminated by a ring 2d delimiting the opening or the mouth making it possible to fill or empty the container. The capacity or the content of the container 2 is the volume of liquid which it contains through the internal surface of its wall when the container rests at its bottom, in static equilibrium generally by gravity on a horizontal plane called the mechanical laying plane Pp.

The brimful capacity of the container 1 corresponds to the volume of liquid filling the container up to the so-called plane of the ring Pb passing through the ring 2d of the container, and more precisely at the level of the surface of the ring of the container. The nominal capacity Cn of the container 1 corresponds to the volume of liquid filling the container up to a level plane Pn for filling the liquid, extending parallel to the mechanical laying plane Pp and located at a determined height Hn from the ring plane Pb .

The determination of the capacity of the sample container 2 involves a step of analyzing the three-dimensional digital model M of the sample container 2 aimed at;

- determining the internal surface Sf of the three-dimensional digital model M of the sample container 2;

- Positioning a filling level plane Pn on the three-dimensional digital model M of the sample container 2 parallel to the laying plane and at a distance Hn from the top of the digital model of the container;

- To measure by calculation, the internal volume of the three-dimensional digital model M delimited by the internal surface Sf and by the filling level plane Pn, knowing that this measurement corresponds to the filling capacity Cn of the container.

From the three-dimensional digital model M, the method consists in determining the internal surface Sf of the three-dimensional digital model as corresponding to the internal surface of the sample container 2.

The method then consists in positioning the filling level plane Pn so as to close the internal surface of the three-dimensional digital model M of the sample container 2. Thus, a closed surface is defined which completely surrounds or envelops the filling volume of the container.

The method then consists in measuring by calculation the interior volume delimited by this closed surface, namely by the internal surface Sf of the three-dimensional digital model M and the filling level plane Pn. Indeed, the internal volume delimited by this closed surface corresponds to the internal filling volume of the sample container up to the filling level.

According to an advantageous embodiment characteristic, the method consists in positioning the three-dimensional digital model M of the sample container placed on its bottom on a reference plane Pr of the virtual space considered as horizontal by hypothesis. As this reference plane simulates the laying of the sample container on a mechanical laying plane, this reference plane Pr is also designated by a virtual laying plane.

As explained previously, the virtual installation plane can be the representation of the mechanical installation plane in virtual space.

Then, the filling level plane Pn is positioned parallel to the reference plane or virtual landing plane Pr at a distance Hn from the top of the three-dimensional digital model of the container.

According to an advantageous variant embodiment, the method consists in positioning the three-dimensional digital model M of the sample container on the reference plane or virtual positioning plane Pr so that by simulation of gravity, the three-dimensional model of the container is found. standing in static equilibrium on three points of its bottom in contact with the reference plane or virtual installation plane Pr. This technique takes into account the value of a density for the material constituting the container.

According to another advantageous variant embodiment, the method consists in positioning the three-dimensional digital model M of the container on the reference plane or virtual laying plane Pr so that by simulation of gravity, the three-dimensional digital model of the virtually filled container up to the level plane of filling by a liquid of determined density, is standing in static equilibrium on three points of its bottom in contact with the reference plane or virtual laying plane Pr. This simulation method makes it possible to approach as closely as possible the reality of a container filled with a liquid and resting on a laying plane defining the filling level plane.

In the case where the filling level plane Pn is positioned at a distance Hn from the top of the three-dimensional digital model M of the sample container, the top of the three-dimensional digital model M of the container is determined as the point belonging to the three-dimensional digital model, the most remote from the reference plane or virtual pose plane Pr or as the point of intersection of a ring surface plane Pb of the three-dimensional digital model with an axis of symmetry of said model. In the latter case, the axis of symmetry is substantially orthogonal to the reference plane or virtual laying plane Pr and the ring surface plane Pb is defined as a plane passing through three points of the ring surface, or a mean plane of the ring surface or a plane positioned in static equilibrium on the ring surface. Of course,

It follows from the above description that in order to measure the capacity at the edge of the container, the method consists in positioning the filling level plane Pn at a distance Hn of zero from the top of the three-dimensional digital model.

According to a variant of the method, to measure the capacity at the edge of the container, the method consists in considering that the filling level plane Pn coincides with the surface plane of the ring Pb.

In the same direction, to measure the nominal capacity Cn of the container, the method consists in positioning the filling level plane Pn at a nominal distance Hn from the top of the three-dimensional digital model.

Another measure of sample container volume 2 is the volume of the sample container shell. This measurement makes it possible to go back to the volume of the identified finishing mold from which the sample container 2. For the determination of the volume of the envelope of the sample container, the method consists of:

- determining the external surface Se of the three-dimensional digital model M of the sample container 2;

- determining a volume closure plane as being the ring surface plane Pb or the lower ring mold seal plane;

- And measure by calculation the internal volume delimited by the external surface Se and the closure plane as being the volume of the envelope of the sample container.

According to an advantageous variant, the volume of the identified finishing mold from which the sample container 2 comes is determined by considering the shrinkage of the sample container due to the cooling that it has undergone between the time of its molding and the time of acquisition of the images. radiographic.

According to another variant of this measurement, it is possible to determine which part of the identified finisher mold is involved, by dividing the measured volume, by the virtual mold parting line Pv into two half-mold volumes. In doing so, for greater precision, it is also possible to envisage eliminating the influence of the volume contained in the molds of the ring and the volume contained in the bottom mold. Indeed, the positions of all the mold gaskets and joint planes being determined in the mold reference X, Y, Z, they are known in the virtual reference Xv, Yv, Zv, according to the invention. It is therefore possible to subtract from the volume of the external surface, the volumes contained in the molds of the ring and of the base.

Another volume measure of the sample container 2 is the glass volume of the sample container. To this end, the method consists in determining the volume of the wall of the three-dimensional digital model M of the sample container, corresponding to the volume of the glass wall of the sample container 2. The method aims to determine the area which completely encompasses the wall of the model. three-dimensional digital M, and which therefore comprises the internal surface Sf connected at the level of the ring by the ring surface, to the external surface Se. This volume is a first usable measure of the glass volume of sample container 2.

Another volume measure of sample container 2 is the actual glass volume of the sample container. This measurement takes into account the lack of material in the wall of the sample container, which is in the form of bubbles. To this end, the method analyzes the three-dimensional digital model M by looking for bubbles corresponding to material shortages between the internal surface Sf and the external surface Se. The method measures the volumes of said bubbles, which are then subtracted from the volume of the wall of the three-dimensional digital model M, determined between the internal surface Sf and the external surface Se. This volume measurement corresponds to the volume of glass of the parison loaded into the identified blank mold, the blank of which has been transferred into the finishing mold from which the sample container 2 is taken. The bubbles taken into account are bubbles with a dimension greater than a threshold. Indeed, the extremely fine bubbles and evenly distributed in the material are linked to the refining of the glass in the oven. The tomograph would need a very high resolution to see them, which increases the cost of the equipment (nano-focus and the resolved sensor) and the cost of use due to the acquisition time that would be necessary with the equipment currently available. These refining bubbles being present in the parison are not to be taken into account for the calculation of the parison volume based on the volume of the container. On the other hand, bubbles with dimensions greater than a given threshold, which are visible with a single micro-focus tomograph, are created in the delivery channels or during loading or even during rough drilling for larger ones. It is therefore necessary to subtract their volume from the volume of the container in order to calculate the parison volume from the actual volume of the container.

The presence, dimensions and position of the loading or blowing bubbles or broths constitute a quality criterion of the sample container in relation to the process parameters such as the forming of the parisons (the temperature of the glass too cold near the plunger), the conditions for loading the parison into the blank, ventilation of the blank and punch mold (too hot) and other conditions for drilling the blank.

According to an advantageous characteristic of using the measurements of the volumes of the sample container, the method according to the invention consists in:

- Consider as being a measurement of the volume of the parison loaded in the blank mold, the volume of glass of the three-dimensional digital model M, with or without taking into account the material shortages;

- Consider the internal volume delimited by the external surface Se of the three-dimensional digital model M and a closure plane as being a measurement of the internal volume of the identified finishing mold;

- consider the volume delimited by the internal surface Sf of the three-dimensional digital model and a filling level plane Pn as being a measure of the capacity of the sample container;

- Deducing from the measurements of the capacity of the sample container and of the internal volume of the finishing mold, the volume of the parison to be loaded into the blank mold from which the sample container 2 comes;

- And decide when the capacity of the sample container is not compliant, to modify the weight of the parison for at least the blank mold from which the sample container originates or to replace the finishing mold.

Of course, one and / or the other of the measurements of the volumes of the sample container make it possible to deduce adjustment information for various other control parameters of the forming process in relation to the mold of the sample container. Measuring the capacity may lead to modifying, for example, the device for extracting the finishing mold. The parison volume measurement can be used to adjust the parison source and the scissor cut. The measurement of the internal volume of the identified finisher mold can make it possible to identify abnormal wear linked to lubrication parameters (frequency, dosage).

The following description aims to describe, as a quality indicator A of the sample container, the rendering of reliefs B arranged on the sample container 2.

By relief B, it is understood in particular, reliefs carried by the external surface of the receptacles such as the mold seal reliefs or reliefs arranged on the receptacles either for aesthetic functions such as coats of arms or decorative engravings or for functions technical (text, code or other inscription of capacity, mold number, batch number, brand, model) or either for mechanical functions such as the counter ring or cap thread, lug or positioning notch, contact streaks bottom, label guard.

The method according to the invention aims to inspect the relief (s) B whose rendering or appearance is to be checked, in particular by checking their geometric characteristics. In the example illustrated in FIG. 12, the relief B on the sample container 2 corresponds to a shield arranged at the level of the shoulder on the external surface of the sample container. Of course, it can be chosen to partially or completely inspect one or more of the reliefs present on the sample container 2.

The method consists in locating on the three-dimensional digital model M as illustrated in FIG. 13A the virtual relief Bv corresponding to the relief B of the sample container 2, All the localization methods can be implemented knowing that this localization is all the more facilitated by the fact that, as explained previously, the position of the three-dimensional digital model M , is known in the virtual frame whose relation to the mold coordinate system is also known.

For the determination of the rendering of a relief B, several methods are possible, considering that the rendering of the virtual relief corresponds to the rendering of the relief carried by the sample container. According to the example illustrated more precisely in FIG. 13 B, the method according to the invention consists of:

- Positioning at least one section plane CC on the three-dimensional digital model M of the sample container so that it sections at least part of said virtual relief Bv;

- determining in the section plane CC, the representative curve Cr of the section of the virtual relief;

superimposing at least partially on the representative curve Cr, a zero altitude curve Ca corresponding to the curve of the external surface Se of the sample container devoid of said relief;

and compare the representative curve Cr with the zero altitude curve Ca, by calculating a criterion for rendering the relief B which can be presented in different magnitudes.

For example, as a criterion for rendering the relief B, a distance can be taken between the zero altitude curve Ca and the representative curve Cr. It is also possible to take a slope deviation at a given position between the zero altitude curve Ca and the representative curve Cr or a variation of the slope of the representative curve Cr. Fig. 13B illustrates in the form of an angle alpha, the slope deviation at a given position between the zero altitude curve Ca and the representative curve Cr and, by a beta angle, a variation of the slope of the representative curve Cr. The area N delimited by the curves

of aitude zero Ca and representative of Cr can also be taken as a criterion for rendering the relief B.

It should be noted that this variant embodiment is advantageous in the case where the relief has a technical function and whose position is of course known. This method consists of:

selecting on the three-dimensional digital model M, a virtual relief corresponding to a relief with a technical function, the position of which is known;

- Positioning on the three-dimensional digital model M, a section plane so that it intersects said virtual relief in a section plane corresponding to a design or normative definition plan bearing indications of tolerance of the relief with a technical function;

- Obtain a representative curve Cr of the section of the relief;

- measure on this representative curve, a radius of curvature and / or an angle, a length, a distance to a curve Ca of zero altitude;

- compare these measurements with the relief tolerance indications.

For the determination of the rendering of the reliefs, it can be considered, as illustrated in FIG. 13C, another method consisting of:

determining the surface Sr representative of the relief as a portion of the external surface of the three-dimensional digital model M in the zone of interest containing at least part of the virtual relief corresponding to the relief;

superposing at least partially on the external surface Se of the area of ​​interest of the virtual relief, a surface of zero altitude Sa representing the surface of the area of ​​interest devoid of said relief;

and compare the representative surface Sr with the surface of zero altitude Sa, by calculating a criterion for rendering the relief B which may be presented in different sizes such as those described above. Thus, as a criterion for rendering the relief, at least one of the following quantities can be chosen:

• a distance d between the surface of zero altitude Sa and the representative surface Sr;

• the slope deviation a at a given position between the zero altitude surface Sa and the representative surface Sr;

• a variation b of the slopes of the representative altitude surface

Sr;

• volumes V delimited by the surface of zero altitude Sa and the representative surface Sr.

For determining the rendering of the reliefs, another method can be considered as illustrated in FIG. 13D, consisting of:

determining the surface Sr representative of the relief as a portion of the external surface Se of the three-dimensional digital model in the zone of interest containing at least part of the virtual relief corresponding to the relief;

superimposing at least partially on the external surface Se of the area of ​​interest, a theoretical relief surface Sri representing the surface of the area of ​​interest if the relief is rendered correctly;

- compare the representative surface Sr with the theoretical surface Sri, by calculating as a criterion for rendering the relief, at least one of the following quantities:

• a distance between the representative surface Sr and the theoretical surface Sri;

• a slope deviation at a given position between the representative surface Sr and the theoretical surface Sri;

• volumes delimited by the representative surface Sr and the theoretical surface Sri.

One and / or the other of these quantities are compared, for example, with reference values ​​to determine the quality of rendering of these reliefs B to make it possible to deduce therefrom an adjustment information for at least one control parameter of the forming process in relation to the identified finishing mold of the sample container. Typically, to improve the rendering of a relief, it is possible to act generally on the final forming step in the finishing mold, by modifying the ventilation of the mold, or the timing of.

blowing (the duration of the stretching) the duration of blowing, the maintenance of the finishing mold, the evacuation of the vents.

The following description aims to describe, as a quality indicator A of the sample container, the internal geometry of the neck As explained previously, this geometry is defined by the values ​​of internal diameters of the neck at different heights, or even over the entire height.

According to the invention, the method consists, as illustrated in FIG. 14, to be determined in the three-dimensional digital model M, the internal surface Sf corresponding at least to the neck of the sample container. The method consists in choosing a section plane Pg, for example parallel to the laying plane Pr of the model (Fig. 16), and cutting at a given height, the neck of the three-dimensional digital model. It is then possible to measure several diameters from 0 to 360 ° in this section plane. The method consists in measuring in this plane, several diameters of the internal surface and in determining at least the minimum and / or the maximum in the section plane.

It is also possible to determine the ring surface of the three-dimensional digital model in order to determine the plane of the Pbv ring surface of the model as explained previously. Thus, it is possible to determine the diameter at the opening Do (or mouth), for example at a distance p = 5 mm below the mouth, by positioning a cutting plane 5 mm below the ring surface.

The diameters can also be determined over the entire height of the neck, by traversing the neck of the ring surface (or pian of the Pbv ring surface) to the bottom of the neck by a cutting plane parallel to the laying plane Pr or to the Pbv ring surface plane by measuring several diameters from 0 to 360 ° in each of these section planes. It is possible, for example, to determine the minimum diameter over 360 ° for each cutting plane, and to consider this diameter value as a function of its depth of the cutting plane so as to obtain the internal or unblocking profile. FIG. 14A gives by way of example the internal profile measured, that is to say the evolution of the measurements of the minimum internal diameter Di along the vertical axis Zv over the entire height of the neck

Alternatively, to measure the "diameter at opening", which is specified by a minimum and maximum diameter tolerance, for example a tolerance interval of 18mm +/- 0.5, to a given depth from the ring surface , for example 5 mm, it is possible to position in a virtual manner, a first cylindrical surface of 5 mm height, of maximum diameter inscribed in the modeled internal surface of the neck, and likewise a second cylindrical surface of 5 mm height, of minimum diameter containing the modeled internal surface, and to consider as measurements of the diameter at the opening of the sample container, the diameters of the inscribed and excribed cylindrical surfaces, which are respectively compared to the tolerances.

It is also possible to determine a minimum diameter over the entire height of the internal surface of the neck to check the broaching diameter.

The diameter at the opening, the broaching diameter, the internal profile of the neck, are related to parameters of the forming process such as the temperature of the parisons, those of the punches and blank molds, the geometry of the ring molds at the blank, the compression, drilling and blowing “timing”.

The following description aims to describe, as a quality indicator A of the sample container, the measurement of the flatness of the ring surface. The measurement of the flatness of the ring surface carried out on the three-dimensional digital model M can be carried out in various ways.

As shown in Fig. 15, one method consists in determining an annular surface Csb representative of the surface of the ring. Said surface is in theory a plane ring or a perfect torus, but there are other profiles. It is then possible to position a ring surface reference plane Pcsb and analyze the differences between the representative surface of the ring and said plane. The torsions of the surface are measured and analyzed transversely and / or tangentially. These twists can be angles or curvatures of the surface. It is alternatively possible to determine and measure the differences between said three-dimensional curve closed to a reference plane positioned in different ways as explained below. Methods for measuring gaps between surfaces have already been explained. Thus, the comparison of the representative surface with a plane consists in measuring distances between points of surfaces and / or volumes delimited by the surfaces. In this case for example, if the ring surface is correct, the volume between this surface and the ring surface reference plane must be zero.

According to another variant, a three-dimensional curve representative of the ring surface is determined. This curve is for example the set of highest points relative to the virtual exposure plane Pr, detected over the entire periphery of the ring. It may also be the junction points between the internal surface Sf and the external surface Se of the model. It is possible to determine and measure the differences between said closed three-dimensional curve representative of the ring surface and a reference plane positioned in different ways as explained below. Measuring the differences between the representative curve and the reference plane consists, for example, in measuring distances between points on the curve and corresponding points on the ring surface reference plane. These distances are for example along the Zv axis.

The reference plane can be the ring surface plane as explained previously, that is to say either:

I. a plane passing through three points on the surface of the ring; one can find an iterative algorithm simulating the installation of a plane in a position of static equilibrium on the curve representing the ring surface;

II. or else a mean plane of the ring surface, which is for example the plane passing at best according to a mathematical function of distance through the point of the closed surface.

The flatness criterion can also be defined by the curvature of the representative curve which is normally zero (infinite radius of curvature).

Another method is to use the cylindrical coordinates (r,

Z, Q: radius r, height Z, angle Q) with the vertical axis z corresponding to the axis of the neck or the ring. The flatness defects of the ring surface

are often distinguished into at least two types. Defects of the “lack of glass” type are linked to problems with filling the ring mold with molten glass when the parison is loaded into the finishing mold. They are characterized by height differences (Dz) which extend over a small angular amplitude (DQ) around the direction of the vertical axis. "Veiled ring" type defects are generally less marked differences in height, which extend over a greater angular amplitude around the theoretical axis, but are nevertheless annoying defects, often due to sagging, to problems. mechanical during the transfer of extracting articles from the mold, or to thermal problems of glass temperature and cooling.

It thus appears that the measurement of the flatness of the ring surface is a quality indicator that can be linked to parameters of the forming process. For example, a non-delivered type defect corresponds either to an insufficient volume (or weight) of parison to fill the blank mold, or insufficient pressure of the punch in press-blown, or insufficient blowing pressure, or poor compression.

The following description aims to describe, as an indicator of quality A of the sample container, external diameters of the body of the sample container.

According to the invention, the method consists, as illustrated in Fig, 16, in determining in the three-dimensional digital model M, the external surface Se corresponding to at least the part of the sample container for which an external diameter is to be measured, The method consists in choosing at a given height a section plane Pd for example parallel to the virtual laying plane Pr of the model, and in measuring several diameters Dv from 0 to 360 ° in this section plane with respect to the external surface Se. Of course, provision can be made to position the section plane at different heights of the body of the sample container at which the outside diameter is to be measured. The method consists in comparing these measurements with reference values.

The measurement of the outside diameters of the body of the sample container is a quality indicator that can be linked to parameters of the forming process such as the cooling of the molds, the maintenance of the molds, the time between mold opening and extraction, etc.

It should be noted that the machine 1 according to the invention also makes it possible to determine various other quality indicators of the sample container. From the analysis of the three-dimensional digital model M, it is possible to measure:

• the verticality of the body, neck or overall sample container; e at as many heights as desired, the external diameters of the body, their minimum and maximum and the ovality of the sample container;

• the height of the sample containers;

• the inclination of the ring relative to the bottom of the sample container;

• the orientation of the ring relative to the body of the sample container;

• the quality of the mold joints (from the burrs left at the mold joints);

• abnormal curvature of the indented or bumpy (swollen) wall of the sample container;

• a sagging shoulder of the sample container.

It emerges from the foregoing description that the machine 1 according to the invention can have different configurations depending on the users' need to know the quality indicator (s) of the sample container.

According to an advantageous configuration, the machine according to the invention is able to determine, as a quality indicator of the sample container, at least one quality indicator taken from the following list, namely:

- the distribution of the glass of the sample container;

- the measurement of at least one volume of the sample container taken from the capacity of the sample container, the volume of the envelope of the sample container, the volume of glass of the sample container and possibly the volume of glass of the parison loaded into the mold identified blank from which the blank was transferred into the finishing mold from which the sample container 2 originated;

- and the rendering of reliefs arranged on the sample container.

According to another advantageous configuration, the machine according to the invention is able to determine as a quality indicator of the sample container, the measurement of the capacity of the sample container, the volume of the envelope of the sample container, the volume of glass. of the sample container and optionally, the volume of glass of the parison loaded into the identified blank mold, the blank of which has been transferred into the finishing mold from which the sample container 2 is taken.

According to another advantageous configuration, the machine according to the invention is able to determine, as an indicator of the quality of the sample container, the distribution of the glass of the sample container, the measurement of the capacity of the sample container, the volume of the envelope. of the sample container, the glass volume of the sample container and optionally, the volume of glass of the parison loaded into the identified blank mold, the blank of which has been transferred into the finishing mold from which the sample container 2 comes.

According to another advantageous configuration, the machine according to the invention is able to determine, as an indicator of the quality of the sample container, the rendering of reliefs arranged on the sample container, the distribution of the glass of the sample container, the measurement of the capacity. of the sample container, the volume of the envelope of the sample container, the volume of glass of the sample container and optionally, the volume of glass of the parison loaded into the identified blank mold whose blank has been transferred into the finishing mold from which is from the sample container 2.

According to another advantageous configuration, the machine according to the invention is able to determine, as an indicator of the quality of the sample container, the rendering of reliefs arranged on the sample container, the distribution of the glass of the sample container, the measurement of the capacity. of the sample container, the volume of the envelope of the sample container, the volume of glass of the sample container and optionally, the volume of glass of the parison loaded into the identified blank mold whose blank has been transferred into the finishing mold from which is from sample container 2, and at least one other criterion taken from the following list:

- the internal geometry of the neck of the sample container;

- the flatness of the surface of the ring of the sample container;

- the outside diameters of the body of the sample container.

According to another advantageous configuration, the machine according to the invention is able to determine, as an indicator of the quality of the sample container, the distribution of the glass of the sample container, the measurement of the capacity of the sample container and at least one other criterion taken. from the following list:

- the internal geometry of the neck of the sample container;

- the flatness of the surface of the ring of the sample container;

- the outside diameters of the body of the sample container.

According to an advantageous embodiment characteristic, it can be carried out an operation of matching the three-dimensional digital model of the sample container with a three-dimensional digital reference model, representing a perfect container, then to determine the dimensional differences by measuring distances between surface elements belonging to the digital reference model and surface elements belonging to the three-dimensional digital model.

It should be noted that the machine 1 in accordance with the invention may include various means of loading and unloading. These means may include a conveyor, a linear actuator with a gripper, a robot arm, a trolley provided with cells receiving series of sample containers to be measured, etc.

The computer 38 can be connected to various organs, such as a supervision system, a control and statistical analysis system, a system for controlling the forming installation.

The machine 1 is preferably installed near the manufacturing installation as shown in FIG. 1 and the sample vessels are taken at the latest before entering the annealing arch of the installation, they are generally still hot, If the sample vessels are taken after passing through the annealing arch, then the time reaction time to take into account the indicators and modify the parameters of the process is lengthened in the order of 30 minutes to 1 hour, which is not favorable to the good use of the quality indicators.

It is therefore conceivable but unfavorable to install the machine 1 away from the manufacturing machine, for example in the cold sector, after the annealing arch, or close to a quality service.

The invention is not limited to the examples described and shown because various modifications can be made to it without departing from its scope.
CLAIMS

1 - Method for controlling a process for forming glass containers (2) implementing an installation with several distinct forming sections (12) in each of which at least one parison of molten glass (18) is first formed of a blank in at least one blank mold (13), then secondly final shaping in at least one finishing mold (14), characterized in that it comprises the following steps:

- Take a container said sample from a blank mold (13) identified and a finishing mold (14) identified;

- depositing the sample container (2) on a sample holder (31) of a computer assisted X-ray tomography machine (30);

- Acquiring by means of the tomography apparatus (30), several radiographic images of the sample container under different projection angles;

- transmitting the radiographic images to a computer (38);

- provide the computer with the position of the sample container in the finishing mold, in a mold mark;

- analyze the radiographic images by the computer to:

· Construct in a virtual frame, a three-dimensional digital model (M) of the sample container from the radiographic images;

• determine the position of the three-dimensional digital model with respect to the position of the sample container in the mold mark;

- and analyze the three-dimensional digital model (M) to determine at least one quality indicator (A) of the sample container in relation to at least one region of the sample container, making it possible to deduce therefrom adjustment information for at least one control parameter of the forming process in relation to the mold of the sample container.

2 - Method according to claim 1, characterized in that, in order to determine the position of the three-dimensional digital model (M) relative to the position of the sample container (2) in the mouie mark, the method consists in locating a marking relief ( R) on the sample container and to place the sample container on the sample holder (31) so that its marking relief (R) is positioned relative to a visual or mechanical tracking device of the sample holder.

3 - Method according to claim 1, characterized in that to determine the position of the three-dimensional digital model (M) relative to the position of the sample container in the mold mark, the method consists of:

- choose a marking relief (R) on the sample container whose position is known in the mold marker;

- Locate on the three-dimensional digital model (M), the virtual location relief (Rv) corresponding to the location relief (R) chosen;

- And determine the position of the virtual registration relief in the virtual coordinate system in order to deduce therefrom the position of the three-dimensional digital model (M) in the mold coordinate system.

4 - Method according to the preceding claim, characterized in that it consists in constructing the three-dimensional digital model (M) taking into account the sample holder (31) so as to have a virtual vertical axis extending perpendicularly through relative to the virtual installation plane (Pr) of the sample container on the sample holder and to ensure a relative rotation around the virtual vertical axis, of the three-dimensional digital model (M) in order to bring the virtual registration relief (Rv) in a position corresponding to the position of the marking relief in the mold mark.

5 - Method according to one of the preceding claims, characterized in that it consists in identifying the blank mold (13) and / or the finishing mold (14) from which the sample container taken by a mold number or d 'location and to make available this mold number or this location number in relation to the quality indicator of the sample container.

6 Method according to the preceding claim, characterized in that to identify the blank mold (13) and / or the finishing mold (14) from which the sample container is issued bearing a relief which indicates the mold number or location under in the form of a code or alphanumeric, the method consists of:

- read the relief carried by the sample container and communicate the number read to the computer (38);

- or to analyze the three-dimensional digital model (M) of the sample container (2), by searching for the location of a virtual relief corresponding to the relief of the sample container, and to read this virtual relief for its provision to the computer (38 ).

7 - Method according to one of the preceding claims, characterized in that it consists in taking the sample container (2) at the latest before entering the annealing arch of the installation.

8 - Method according to one of the preceding claims, characterized in that it consists in determining a quality indicator (A) of the sample container, making it possible to deduce adjustment information for at least one control parameter of the forming process containers for the identified mussels, among:

- the weight or shape of the glass parison loaded into the identified blank mold;

- The position or speed of the glass parison (18) when it is loaded into the identified blank mold;

- synchronization or speed or force in the movement of the mechanisms of the piercing punches, of the identified molds, of the transfers of the blank, of the extraction clamps;

- cooling of the identified molds or of an associated punch;

- a blowing or pressing pressure for the identified molds;

- the replacement of an identified mold.

9 - Method according to one of the preceding claims, characterized in that it consists in determining as a quality indicator (A) of the sample container (2), the distribution of the glass of the sample container. 10 - Method according to one of the preceding claims, characterized in that it consists in determining, as a quality indicator (A) of the sample container, at least one volume measurement of the sample container taken from, the capacity (Cn ) of the sample container, the volume of the envelope of the sample container and the volume of glass of the sample container.

11 - Method according to one of the preceding claims, characterized in that it consists in determining as a quality indicator (A) of the sample container, the rendering of reliefs (B) arranged on the sample container.

12 - Method according to one of the preceding claims, characterized in that it consists in determining, as a quality indicator (A) of the sample container, the internal geometry of the neck of the sample container.

13 - Method according to one of the preceding claims, characterized in that it consists in determining as a quality indicator (A) of the sample container, the flatness of the ring surface of the sample container.

14 - Method according to one of the preceding claims, characterized in that it consists in determining as a quality indicator (A) of the sample container, the outer diameters of the body of the sample container.

15 - Method according to claim 9, characterized in that it consists in determining the distribution of glass as a quality indicator (A) of the sample container, in determining the position of the center of mass (Gv) of the model three-dimensional digital (M) or of a portion of said model, and by comparing this position with a reference position (Gr).

16 - Method according to claims 9 or 15, characterized in that it consists in determining the distribution of glass as a quality indicator (A) of the sample container, in determining the thickness of the glass wall on at least one region of the sample container (2), by searching in this region for the position of a zone with a thickness greater than a predefined value and / or a thickness less than a predefined value, possibly by determining the extent of said zone , and / or by searching for the presence and the position of the part of the wall having the minimum or the maximum thickness in said region.

17 - Method according to one of claims 9, 15 or 16, characterized in that it consists for the determination of the distribution of glass as a quality indicator of the sample container:

determining the volume of glass contained in at least two regions of the three-dimensional digital model divided either by a vertical section plane containing the virtual vertical axis of the three-dimensional digital model or by a horizontal section plane perpendicular to said virtual vertical axis;

- and comparing said volumes with reference volume values ​​and / or between several regions of the same sample container, and / or between several sample containers.

18 Method according to claim 11, characterized in that it consists in determining the rendering of reliefs (B) arranged on the sample container as an indicator of the quality of the sample container;

- position at least one section plane (CC) on the three-dimensional digital model (M) of the sample container so that it cuts at least part of a virtual relief (Br) of the external surface (Se) of said model and corresponding to the relief (B);

- determining in the section plane, the representative curve (Cr) of the section of the virtual relief (Br);

- superimposing at least partially on the representative curve (Cr), a zero altitude curve (Ca) representing the curve of the external surface (Se) of the sample container devoid of said virtual relief (Br);

- compare the representative curve (Cr) with the zero altitude curve (Ca), by calculating as criterion for rendering the virtual relief (Br) at least one of the following quantities:

• a distance between the representative curve (Cr) and the zero altitude curve (Ca);

• a slope deviation at a given position between the representative curve (Cr) and the zero altitude curve (Ca);

“A variation of the slope of the representative curve (Cr);

® an area delimited by the representative curve (Cr) and the zero altitude curve (Ca).

19 - Method according to claims 11 or 18, characterized in that it consists in determining the rendering of reliefs (B) arranged on the sample container (2) as a quality indicator (A) of the sample container to:

- determining the representative surface (Sr) of the relief as a portion of the external surface of the three-dimensional digital model in the area of ​​interest containing at least part of a virtual relief corresponding to the relief (B);

- superimposing at least partially on the external surface of the zone of interest, a surface of zero altitude (Sa) representing the surface of the zone of interest devoid of said virtual relief;

- compare the representative surface (Sr) with the surface of zero altitude (Sa), by calculating as a criterion for rendering the relief at least one of the following quantities:

• a distance between the surface of zero altitude (Sa) and the representative surface (Sr);

• the slope deviation at a given position between the surface of zero altitude (Sa) and the representative surface (Sr);

• a variation in the slopes of the representative surface (Sr);

® volumes delimited by the surface of zero altitude (Sa) and the representative surface (Sr).

20 - Method according to one of claims 11, 18 or 19, characterized in that it consists in determining the rendering of reliefs arranged on the sample container as a quality indicator of the sample container:

determining the surface representative of a virtual relief (Sr) as a portion of the external surface of the three-dimensional digital model in the zone of interest containing at least part of the virtual relief corresponding to the relief of the sample container;

- Superimposing at least partially on the external surface of the area of ​​interest, a theoretical relief surface (Sri) representing the surface of the area of ​​interest if the virtual relief is rendered correctly;

- compare the representative surface (Sr) with the theoretical surface (Sri), by calculating as a criterion for rendering the relief, at least one of the following quantities:

• a distance between the representative surface (Sr) and its theoretical surface (Sri);

• a slope deviation at a given position between the surfaces (Sr) and (Sri);

• volumes delimited by the surfaces (Sr) and (Sri).

21 Method according to one of claims 11, 18, 19 or 20, characterized in that it consists in determining the rendering of reliefs arranged on the sample container as a quality indicator of the sample container at:

- select on the three-dimensional digital model (M), a virtual relief corresponding to a relief with a technical function, the position of which is known;

- Positioning a section plane so that it intersects said relief in a section plane corresponding to a design plane;

- obtain a representative curve (Cr) of the section of the virtual relief;

- measure on this representative curve, a radius of curvature and / or an angle, a length, a distance to a curve (Ca) of zero altitude;

- compare the measurement with predefined tolerance values.

22 - Method according to claim 10, characterized in that it consists in determining the capacity (Cn) of the sample container as a quality indicator of the sample container, in:

- determining the internal surface (Sf) of the three-dimensional digital model (M) of the sample container;

- determining a filling level plane (Pn) on the three-dimensional digital model of the sample container, the filling level (Pn) being either the virtual ring surface plane (Pr) or a nominal filling level plane;

- And measure by calculation, the internal volume of the three-dimensional digital model of the sample container delimited by the internal surface (Sf) and the filling level plane, this measurement being the capacity (Cn) of the sample container.

23 Method according to claim 10, characterized in that it consists for determining the volume of the envelope of the sample container as a quality indicator of the sample container at:

- determining the external surface (Se) of the three-dimensional digital model of the sample container;

- Determine a volume closure plane (Pf) as being the ring surface plane or the lower ring mold seal plane;

- And measure by calculation the internal volume delimited by the external surface and the closure plane as being the volume of the envelope of the sample container.

24 - Method according to claim 10, characterized in that it consists, for determining the glass volume of the sample container as a quality indicator (A) of the sample container, in determining the volume of the wall of the three-dimensional digital model of the sample container.

25 - Method according to the preceding claim, characterized in that it consists in analyzing the three-dimensional digital model (M) by looking for bubbles corresponding to shortages of material between the internal surface (Sf) and the external surface (Se), and in measuring the volumes of said bubbles, which are then subtracted from the volume of the wall of the three-dimensional digital model (M), determined between the internal surface (Sf) and the external surface (Se), in order to obtain a volume corresponding to the volume glass of the parison loaded into the identified blank mold, the blank of which has been transferred into the finishing mold from which the sample container (2) originates.

26 - Method according to the preceding claim, characterized in that it consists in:

- consider as being a measurement of the volume of the parison loaded in the blank mold, the glass volume of the three-dimensional digital model (M), with or without taking into account the material shortages;

- consider the internal volume delimited by the external surface of the three-dimensional digital model (M) and a closing plane as being a measure of the internal volume of the finishing mold;

- consider the volume delimited by the internal surface of the three-dimensional digital model (M) and a filling level plane as being a measure of the capacity (Cn) of the sample container;

- Deducing from the measurements of the capacity (Cn) of the sample container and of the internal volume of the finishing mold, the volume of the parison to be loaded into the blank mold from which the sample container comes;

- And decide when the capacity of the sample container is not compliant, to modify the weight of the parison for at least the blank mold from which the sample container originates or to replace the finishing mold.

27 - Method according to claim 12, characterized in that it consists, for its determination of the geometry of the neck of the sample container as a quality indicator of the sample container:

- determining on the three-dimensional digital model (M) the internal surface corresponding at least to that of the neck;

- positioning at least one cutting plane (Pg) parallel to a virtual laying plane (Pr);

- measure in this plane several diameters of the internal surface and determine the minimum and / or the maximum in the section plane.

28 - Method according to the preceding claim, characterized in that it consists in determining as an indicator of the geometry of the neck:

- the diameter at the opening;

- and / or the broaching diameter;

- and / or the internal profile of the sample container.

29 - Method according to claim 13, characterized in that it consists, for the determination of the flatness of the ring surface of the sample container as a quality indicator of the sample container:

- determining from the three-dimensional digital model (M), a closed three-dimensional curve or an annular surface representative of the ring surface;

- positioning a ring surface reference plane in relation to the closed three-dimensional curve or to the annular surface;

- and measure the differences between the reference plane and the closed three-dimensional curve or the annular surface.

Method according to claim 14, characterized in that it consists, for the determination of the outer diameters of the body of the sample container as an indicator of the quality of the sample container;

- determining from the three-dimensional digital model (M), the external surface (Se) corresponding to at least the part of the sample container for which an external diameter is to be measured;

- Positioning a section plane (Pd) parallel to the virtual laying plane (Pr) of the model according to at least one height of the container;

- measure several diameters in this section plane with respect to its external surface and compare these measurements with reference values.

31 - Machine for controlling a glass container forming process implementing an installation with several distinct forming sections (12) in each of which at least one parison of molten glass (18) is first formed into a blank in at least one blank mold (13), then secondly final shaping in at least one finishing mold (14), characterized in that it comprises:

- a computer assisted X-ray tomography apparatus (30), capable of producing several radiographic images at different projection angles of a sample container placed on a sample holder of said apparatus;

- a device (39) for knowing the position of the sample container in the finishing mold, according to a mark on the mold;

- a computer (38) connected to the device (39) and to the tomography apparatus (30) and configured to analyze the radiographic images for:

• construct in a virtual frame, a three-dimensional digital model (M) of the sample container from the radiographic images;

• determine the position of the three-dimensional digital model (M) with respect to the position of the sample container in the machine coordinate system;

• analyze the three-dimensional digital model (M) to determine at least one quality indicator of the sample container in relation to at least one region of the sample container, making it possible to deduce therefrom adjustment information for at least one control parameter of the method of forming in relation to the mold of the sample container;

- and a system (41) for delivering at least the quality indicator (A) of the sample container in relation to at least one region of the sample container.

32 - Machine according to the preceding claim, characterized in that the system (41) for delivering at least the quality indicator of the sample container in relation to at least one region of the sample container

comprises a display system (42) for the quality indicator in relation to the identity of the finishing mold.

33 - Machine according to the preceding claim, characterized in that the system (41) for delivering at least the quality indicator of the sample container in relation to at least one region of the sample container comprises a connection (43) for transmitting to a control system (23) of the forming installation, the quality indicator (A) in relation to the identity of the finishing mold.

34 - Machine according to one of claims 31 to 33, characterized in that it comprises a system (40) providing the computer (38), the mold number or location of the sample container (2).

35 - Installation for forming glass containers comprising several distinct forming sections (12) in each of which at least one parison (18) of molten glass is first formed from a blank in at least one blank mold (13 ), then secondly final shaping in at least one finishing mold (14), characterized in that it comprises a machine (21) according to one of claims 31 to 34, arranged at the outlet of the finishing molds .