The present invention relates to the preparation, processing, recycling and utilization of waste composite films (at least two layers), especially those comprising PET (polyethylene terephthalate, polyethylene terephthalate in English) inked.
The invention relates, in particular, a method and a plant adapted for the preparation and densification, for recycling of PET film inked waste from the manufacture of thermal transfer films, as well as heat transfer film rolls Used.

The invention also relates to products obtainable by this method, and possible uses of these products.

The technology called "thermal transfer" used widespread and massive way in the world, allows you to print bar codes, batch numbers ... etc on many media (labels, flexible packaging ...) with good quality, sustainably and in all types of environments. The manufacture and use of thermal transfer rolls of film as a heat transfer printer consumables generate falls thermal transfer film productions and used thermal transfer film rolls.

thermal transfer film waste generally come in three different forms:

- small rolls (film wound around a core of cardboard or plastic) of dimensions (width, diameter ...) heterogeneous of which the width is for example between 30 and 170 mm,

- the "Jumbo", ie the rollers whose width is, for example 1010 mm and the diameter for example, between 450 and 700 mm, and

- a film bulk.

The film is formed for example of a "support film PET" (polyethylene terephthalate) thermoplastic representing between 69% and 76% by weight of the film, an ink layer comprising waxes, resins and the least one pigment, eg carbon black, representing between 24% and 31% by weight, and a "back" consisting of silicone derivatives representing less than 0.3% by mass. The thickness of the thermal transfer film is very low, for example between 8 and 10 μηι.

Current treatment solutions for thermal transfer film waste is disposal options (landfill) or recovery

Energy. Because of their widespread use, recycling of heat transfer film waste is a major economic and environmental issue.

It appears that all conventional methods for transformation and use of the thermoplastic does not accept the presence of cardboard. For thermal transfer film waste roll form and "Jumbo", so it is necessary to separate the cores and the film. There are separation processes guillotine operation or draw for large rolls. However, there are no technically and economically satisfactory solution for small-sized rolls such as small roller above.

As part of its research, the Applicant has carried out thermal transfer film of waste grinding tests. It turned out that, for greater than 1500 μηι particle sizes, the resulting milled is very volatile and that its flow, eg in hoppers, is problematic. One such product is difficult to implement.

It is also known to transform thermoplastic materials at temperatures above the melting temperature of the semi-crystalline polymers or the glass transition temperature for amorphous polymers typically between 150 and 300 ° C.

However, the presence of ink in proportion in the heat transfer film waste creates problems. For example, inks stand interstices of equipment used.

There is also the de-inking processes using chemical baths or mechanical scraping. The purpose of these processes is to get a PET film which would then inked recycled through traditional recycling channels. The disadvantage of these deinking methods is to create new waste containing ink and liquid waste. In addition, processes using solvents have negative toxicological and environmental impacts. The deinking methods are not currently used for the treatment of thermal transfer film waste, at least not on an industrial scale. In addition, there are so far very few applications for PET got inked.

JP-A-2014124855 discloses a method of recycling of used thermal transfer ribbons and the use of recycled products obtained as black coloring agent mixed with the plastics.

This method provides multistage separation films medium or cardboard core. harvested ribbons of waste is then introduced into a vessel equipped with a rotating rotor propeller for performing densification by water. The material is frozen by adding water in the form of small agglomerated granules. The agglomerate undergoes further micronization step to be used in particular as black coloring agent in a mixture with other plastics.

However, the step of agglomeration in the tank is carried out batchwise (batch English), discontinuously. Moreover, the nature of heat transfer films, thin and heavily inked, impedes the agglomeration step. This results in a charcoal black appearance, and the release of a lot of gas.

It therefore appears that the existing methods of processing or preparation for recycling are not suitable for certain types of complex films, including thermal transfer films heavily inked and very thin.

An object of the invention to provide an improved method of producing a densified material directly used and obtained from waste of complex films, including heat transfer, while limiting the number of steps to encourage recycling, and possible uses of the material obtained.

To this end, the invention concerns a method for producing a densified material, the method comprising at least the steps of:

- obtaining a film having at least a first layer of plastic, for example PET, and a second layer of different composition from the first layer, for example ink, the first layer having a first melting temperature, or obtaining pieces of such a film,

- compression of the resulting film or film pieces obtained through at least one of at least one extruder die, and obtaining at least one profile of the densified material, the extruder comprising at least one rotatable auger to push the resulting film or film pieces obtained according to a screw axis with respect to the extruder, and - optional cutting of the profile to obtain pellets of the densified material, the pressing step being performed at a maximum compression of the film obtained or film pieces obtained, the maximum compression temperature being lower than the first melting temperature.

According to particular embodiments, the method comprises one or more of the following features, (s) according to all technically possible combinations:

- the second layer has a second melting temperature lower than or equal to the first melting temperature, preferably lower by at least 10 ° C, the temperature of the compressing step being between the second melting point less than 60 ° C and the second melting temperature 60 ° C, preferably

between the second melting temperature less 35 ° C and the second melting temperature more than 35 ° C;

- the endless screw comprises at least one cutting element for cutting the film obtained or the film pieces obtained, and / or at least a portion in which the screw has an inner diameter perpendicular to the screw axis, the diameter internal being ascending along the axis of screw to compress, at the densification step, the obtained film or film pieces obtained;

- the worm is part of a system with two conical extruder screws;

- the die has a compression height between 1, 5 and 15;

- the extruder defines a sheath traversed by the worm, the worm having a nominal diameter, and separate threads of the sheath by a distance greater than or equal to 0.001 times the nominal diameter; and

- the method further comprises the steps of: obtaining the film by unrolling, the flow being produced by suction of the film or by a direct drive or of the film by the worm, and continuous feed of the extruder in the film.

The invention also relates to an installation for producing a densified material, the installation comprising:

- a source of a film or film pieces, the film comprising at least a first layer of plastic, for example PET, and a second layer of different composition from the first layer, for example of the ink,

- at least one extruder adapted to compress the film or film pieces, the extruder comprising at least one outlet nozzle at least one profile of the densified material, and at least one rotatable auger for urging the film or film pieces along an axis of screw relative to the die, the extruder being adapted to carry out the compression at a maximum compression of the film or pieces of film, the maximum compression temperature being lower than the first melting temperature and

- optionally at least one cutting device adapted to produce granules of densified material from the profile.

The invention also relates to granules of densified material obtainable by a method as described above, a bed of the material densified granules having a bulk density greater than 120 kg / m 3 , and the pellet densified material each having a smallest dimension larger than 2 mm.

The invention also relates to a use of at least one section of material densified or densified material of granules obtained by a method as described above, the profile or the granules being used as:

at. dye to a thermoplastic material,

b. filler within a thermoplastic matrix,

c. raw material in the formulation of thermosetting,

d. raw material in a concrete, cement, asphalt, or a paint, e. raw material in the manufacture of dunnage products,

f. filling material or filling of an empty space,

g. release agent in a thermoplastic matrix,

h. compatibilizer in a mixture with thermoplastic materials to increase the compatibility of said materials with each other or

i. viscosity modifier in a thermoplastic matrix.

The invention will be better understood from reading the description which follows, given as an example only and with reference to the accompanying drawings, wherein:

- Figure 1 is a schematic view of a thermal transfer film roll,

- Figure 2 is a diagram showing a method according to the invention for transforming the roller shown in Figure 1 in the densified material usable for various applications,

- Figure 3 is a schematic view of an installation according to the invention,

- Figure 4 is an axial schematic view of the installation shown in Figure 3,

- Figure 5 is a schematic view of the die of the extruder shown in Figures 3 and 4, and

- Figures 6 and 7 are perspective views of densified material of granules obtained using the plant shown in Figures 3 and 5.

thermal transfer film roll

Referring to Figure 1, there is disclosed a roller one thermal transfer film. The roller 1 is for example a "small roller" as defined above.

The roller 1 has a mandrel axis 3 of D1 mandrel 5 and a film wound around the mandrel around the mandrel axis.

The roller 1 is for example a used roll, that is to say, a roller whose film has been used in a thermal transfer printing machine (not shown) and wound on the mandrel 3.

According to a variant not shown, the roll 1 is a roll which has not been used, but it is desired to recycle. For example, it may be a generation from fall of a thermal transfer film manufacturing process.

The chuck 3 is for example made of cardboard.

The film 5 has a width L along the axis of D1 mandrel, for example between 30 and 170 mm. As shown in enlargement in the right part of Figure 1, the film 5 includes, in this example, a first layer 7 of plastics material and a second layer 9 disposed on a first side 1 1 of the first layer.

The film 5 is said "complex" because it comprises at least two layers of different natures.

The film 5 preferably includes a third layer 13 disposed on a second face 15 of the first layer, the second face being opposite to the first face in a direction E perpendicular to the film locally.

The film 5 has a low thickness E1 in the direction E, of less than 3 mm, and preferably less than 10 μηι.

In general, the term "film" means a flat appearance article which may be wound and extending in a main direction F. For example, the film 5, in unrolled state, is at least 50 times more long in the main direction F, that wide along the axis of D1 mandrel.

According to variants not shown, the film 5 has only the first layer 7 and the second layer 9, or these layers and at least one further, all distinct.

The first layer 7 is made of polymer or mixture of polymers (usually referred to by the term compound) thermoplastic, for example PET.

According to variants, the first layer 7 is HDPE (high density polyethylene), LDPE (low density polyethylene), PP (polypropylene), EVA (ethylene - vinyl acetate), EVOH (ethylene vinyl alcohol), PVC (polyvinyl chloride vinyl), PBT (polybutylene terephthalate), PS (polystyrene), ABS (acrylonitrile butadiene styrene), PMMA (polymethyl methacrylate), PVB (polyvinyl butyral), PA (Polyamide), PC (Polycarbonate) or PEN (poly naphthalate or polyethylene naphthalate) ...

The first layer 7 is for example between 69% and 76% by weight of the film

5.

The first layer 7 has a first T1 melting temperature, for example between 245 and 265 ° C for PET (in particular for the thermal transfer film).

In the present application, the term "melting point" shall be defined as the melting temperature for semi-crystalline polymers or, in an enlarged manner, the glass transition temperature for amorphous polymers.

The second layer 9 comprises, for example, one or more waxes, or one or more resins and at least one pigment or colorant, such as carbon black (including thermal transfer film).

According to variants, the second layer 9 comprises a plurality of inks. The second layer 9 is for example between 24% and 31% by weight of the film 5, preferably about 30%.

The second layer 9 has a second melting temperature T2 lower than T1, for example at least 10 ° C. In the example shown (and in particular for the thermal transfer film), T2 is between 40 and 90 ° C.

The third layer 13 form a "back" comprising silicone, silicone derivatives or mixtures thereof. The third layer 13 is for example less than 0.3% by weight of the film 5.

A method of producing

Referring to Figure 2, there is disclosed a production method according to the invention.

The method transforms the rolls such that the roll 1 and to produce a densified material is in the form of granules 20 of densified material stored in a container 22 for later use, or directly used for various applications.

Alternatively, the method of transforming other rolls of composite films or other films, such as thin films of organic electronics, such as organic photovoltaic films third generation (English OPV organic photovoltaics).

The method comprises a step 30 for obtaining a roller 1, a step 40 of separating the mandrel 3 and the film 5, and 50 a step of feeding an extruder 55 shown in Figs 3 to 4) film 5. the method also includes a step 60 of compression of the film 5 to obtain a densified material section 65, and an optional step of cutting 70 of the profile 65 to obtain the granules 20 of densified material.

Steps 30, 40 and 50 together constitute a step of obtaining the film 5.

Alternatively, the film 5 is obtained in another way, for example in bulk or in the form of pieces (not shown). These pieces are for example obtained by shredding the film 5. Shredding can be done on site or at another location. Shredding is for example made using chippers slowly rotating single or twin rotor (s), fast cutting mills.

The pieces preferably have greater than 1500 μηι dimensions. In this embodiment, the extruder 55 is fed by these pieces and, in step 60 of compression, it is these bits which are densified.

The method finally comprises optionally a step 80 to use granules 20 of densified material obtained, use being made immediately or later, on-site or in another place.

Alternatively, the profile 65 of the densified material is sent directly to step 80 use without passing through the step 70 of cutting, especially when use is local and does not require storage in the form of granules 20 densified material.

Step 40 of the film separation - mandrel

For "small rolls"

The roller 1 is optionally prepared to be able to take place freely. If necessary, a cutting tool such as a cutter or knife is used on the length of the width L to release the film 5. This is done manually or automatically.

For example, the rollers are manually or automatically placed loose on a grid 87 (Figure 3) defining passageways 89 of dimensions smaller than the dimensions of the mandrel 3.

A suction system 91, located below the gate 87 sucks the film 5 and conveys it into a hopper 93 of the extruder 55. The delivery is for example pneumatic.

According to variants not shown, the film 5 is attracted and held by a system generating electrostatic forces, or by an injection system or air suction, such as a pneumatic gun system advantageously placed under the gate 87 .

According to particular embodiments, the gate 87 is driven movements (not shown) relative to the extruder 55, tilt and / or translation, and / or is mounted on a vibrating table (not shown) for increase the efficiency of separation.

In one particular embodiment not shown, the gate 87 is closed and form a cage around the rollers during separation for safety issues.

When the film 5 is fully unrolled from the rollers, the mandrels 3 are discarded. The cores are removed for example by tilting the grid 87.

To obtain a continuous feed of the extruder 55, a turning system (not shown) having a plurality of indexed grids is advantageously used. Such a system comprises for example a filling current grid, two gates located on the vacuum system, and a gate for discharging the mandrels. The rotation of the grids is carried out when there is more than mandrels (without film 5) on the one of the two grids having been placed on the vacuum system since the longest duration.

Always in order to allow a continuous operation, the grid being filled is advantageously placed on weighing system (not shown) for introducing a relatively constant weight by gate rollers.

According to another example (not shown), the rollers are placed on mobile unwinders for free rotation about their axis. The film 5 is driven by the worm screw 95 of the extruder 55, or by pulling systems with rollers or belts, or by suction systems.

The worm screw 95 passes through a sleeve 97 defined by the extruder 55 and extends along a screw axis D2.

Advantageously, the film 5 is twisted on itself in order to facilitate incorporation into the extruder 55.

Another possibility is to place the rollers horizontally (lying down) on a motorized axis. The assembly is placed vertically with respect to the extruder 55. The motorized shaft rotates the roller 1 in the direction of unwinding of the film 5, which preferably falls by gravitation.

For the "Jumbo"

The "Jumbo" are for example placed on drives to unwind the film 5.

The "Jumbo" are either placed securely on one of their sides, or mounted on a freewheel in rotation, or motorized. In order to increase the input capacitance film, several "Jumbo" are advantageously held simultaneously.

The unwinding of the film is carried out by driving the screw of the extruder 55, by pulling systems (roller pulling system or belt pulling system), or by suction systems.

In the latter case, a closed chamber (not shown) wherein the "Jumbo" is placed on a freewheel (or motor) to rotate is used. This allows the sequence of "Jumbo" multi turns (consisting of several unrelated film lengths therebetween but being wound onto the same mandrel) without human intervention.

The film advantageously 5 is twisted on itself in this step to facilitate incorporation into the extruder 55.

Step supply 50 of the film 5 in the extruder 55

For example, the film 5 is incorporated by gravity into the hopper 93 to the worm 95 which drives by friction phenomena.

Alternatively, the suction system (pneumatic conveying type) feeds the film 5 to the worm 95 which drives it by friction.

Alternatively, the power is assisted by a tamper roller (not shown, eg of the same type as those used for extruding rubber) that helps the film 5 to penetrate between the threads 97A of the worm 95. The tamper roller rotates at the same speed as the worm 95, but in opposite direction. At this tamper roller are optionally combined two elements called "brush-scraper" (not shown) placed in upper and lower position and to avoid that the film 5 does not come wrap around the tamper roller.

By "up" and "down" here means the top and bottom of the figure to which it is directly or indirectly refers.

According to a particular embodiment, the power is assisted by two rollers (not shown), movable in rotation and placed in the hopper 93. These two rollers have different directions of rotation for driving the film 5 down and therefore to the (or) the extruder screw 55. the space between these two rollers is large enough to allow the passage of a large volume film 5. to these drive rollers are optionally combined of said catching elements "scraper-brush" positioned in upper and lower position and to avoid that the film 5 does not come wrap around these rollers.

According to a particular embodiment, the power is assisted by a sliding drawer 98 (Figure 4), hydraulically driven and pressing the film 5 against the worm 95. In this case, the hopper 93 is not located above of the worm 95, but is offset perpendicularly to the axis of screw D2.

According to another embodiment, and in particular to film bulk (incorporated in the hopper 93 via a grapple or in the form of balls (obtained during the preconditioning of the bulk film by a press type of equipment bale) Power be assisted by a vertical piston system (not shown), located at the entrance to the hopper 93 and pushing the film 5 in the screw 95 to allow a better grip of the film.

Advantageously, at the feed zone of the extruder 55, the auger 95 includes elements (not shown) for attaching the film 5 more easily.

The sheath 97 is preferably grooved.

Step 60 compression

The film 5 is pushed by the screw 95 inside the sleeve 97 along the axis of screw D2 to a die 99. The film 5 is further compressed into the extruder 55.

The film 5 progressively initially fills the free space between the sleeve 97 and the worm 95, and is compressed in the sleeve 97.

In the example shown, the extruder 55 has a single worm.

According to variants not shown, the extruder 55 is a co-rotating twin-screws (two screws rotating in the same direction) or counter-rotating bis-screws (two screws rotating in opposite directions.

Optionally, the extruder 55 is equipped with one or more vent zones (not shown).

Advantageously, the extruder 55 is devoid of distribution grid and / or filtration system. Metal parts (not shown) as blank rings (for passing the flow of material) are optionally placed at the end of the screw 95 instead of a grid and / or system filtration.

The extruder 55 has for example a right head which allows to remove the rail in the extension of the axis of the screw or D2.

The sleeve 97 is preferably cylindrical.

The die 99 is for example located in the axial extension of the auger

95.

The worm 95 is single or double thread (s). The screw 95 has an axially length LL and a nominal diameter DN (diameter of the threads 97A) by constant following example the axis of screw D2. The worm 95 includes, for example, successively in the axial direction, a portion 101 in which the screw has a constant inner diameter Dl, and a portion 103 in which the inner diameter increasing along the axis of screw to D2 the sector 99.

Advantageously, the worm 95 and the sleeve 97 are separated by a greater distance ES or equal to 0.001 times the nominal diameter DN.

ES distance is for example constant along the axis of screw D2.

Part 101 comprises, for example, cutting elements 105, advantageously located on the radial ends of the threads 97A of the worm 95, and adapted to cut the film 5.

The cutting elements 105, optionally in combination with non-represented against knives, used to shred and grind the film 5 during its conveying.

In the portion 103, the height and volume of the threads 97A of the screw 95 decreases.

A heat input is optionally carried inwardly of the sleeve 97 to heat the film 5.

Under the combined action of the worm 95 and the possible supply of heat, the film 5 is pressed through the die 99 to form the densified material in the form of the profile 65 of the densified material.

Alternatively (not shown), the extruder 55 has several dies, and optionally several screw, and more densified material profiles are obtained at the output of the extruder.

The extruder 55 is advantageously controlled in temperature, for example at the sleeve 97.

An important parameter is the maximum temperature Tm at which compression is carried the film 5 during step 60 of compression.

Tm is lower than the first melting temperature T1.

In addition, it is advantageous if Tm is between the second melting temperature T2 least 60 ° C and T2 greater than 60 ° C, preferably between T2 least 35 ° C and T2 more than 35 ° C.

Thus, the second layer 9 is advantageously acts as a binder during densification resulting in the profile 65 of the densified material. This role binder to ensure and maintain cohesion of PET and thus the densified material rush after leaving the die. The temperature Tm, in particular with respect to T2, also seems to be a parameter for playing on the desired level of hardness to the rod of densified material (hardness defined below).

Advantageously, there is defined a sheath of temperature desired profile 97 and the die 99, taking into account the self-heating related to work of the worm 95 and the shearing and frictional forces of the material in the scabbard. The set temperature profile depends on the film inlet in capacity, rotation speed of screws and dimensions (including length) of the extruder according to the screw axis D2, and extruder screw profiles .

The sheath 97 and / or the die 99 are for example equipped with a thermal control system 107 for heating and / or cooling of the sheath and / or the die.

The system 107 comprises, for example:

- the heating resistive strips (not shown),

- an air cooling device pulsed (not shown), and / or

- a temperature control device (not shown) through fluid flow (water or oil).

According to a variant not shown, the screw 95 is hollow and cooled by water or oil.

According to another variant, the extruder 55 has an adiabatic operation. It is provided with no thermal control system, or they only work in a startup phase of the process. In this case, the heat is supplied only by the internal friction in the extruder 55.

For example, the set temperature profile is along the axis of D2 am going to the die 99, linear, increasing, decreasing, increasing and then decreasing, then increasing or decreasing.

According to an advantageous variant, a feeding area 109 (first part of the worm beginning at the hopper of the extruder 55) is cooled in order to avoid feeding problems (e.g. material plugs in the feed zone or feed irregularities) and a delivery of the film 5 from the extruder.

The speed of rotation of the worm 95 is determined based on flow profile 65 of desired densified material. However, the faster the worm 95 rotating, the higher the self-heating is important, with a risk of exceeding the first melting temperature T1, this risk is reduced if the control devices are used.

In addition, the rotational speed of the worm screw 95 determines the residence time of the film 5 into the extruder 55. According to the configurations, a minimum residence time is recommended to provide the profile 65 of densified material the required properties. The skilled person will adjust the speed according to these parameters.

The speed of rotation of the auger 95 during a filling phase of the sleeve 97, is for example less than the rotational speed during a steady production phase. After filling, the speed is increased more or less rapidly.

An extruder corotating twin-screw allows a pattern of the film supply 5. The use of conical screw allows a compression of the film 5 to As transportation.

According to one embodiment, the ratio of the length LL of the nominal diameter

DN of the endless screw 95 is for example greater than 35, especially when the extruder 55 comprises a thermal regulation system.

According to another embodiment, the ratio of the length LL of the nominal diameter DN is less than 20, in order to limit the residence time in the extruder 55, in particular if the extruder is devoid of a thermal control system or that it is inefficient.

Die 99 shapes the profile 65 of densified material leaving the extruder 55.

In Figure 3, the die 99 is a single output (single port).

Alternatively (not shown), the die 99 has multiple outputs, depending on the film 5 rate input and the dimensions of the orifice or orifices. The die 99 comprises for example a plate or a cylindrical holes lip plate (rectangular section perpendicular to the axis of screw D2).

For example, the diameter of the cylindrical holes or rectangular sections in size from a few millimeters to a few centimeters to achieve or densified material profiles.

Alternatively, the diameter of the holes or cylindrical or rectangular section dimensions between several millimeters and several tens of centimeters for direct use profiles obtained (without cut).

Is defined for the die 99 a compression height as the ratio of a length LF (Figure 5) of the die according to the extrusion direction (here confused with the axis of screw D2) to the diameter D or width D3 orifices in a direction perpendicular to the extrusion direction.

The die 99 preferably has a height of compression between 1, 5 and 15 to select and optimize the degree of densification desired for the densified material.

The level of densification refers to the level of hardness of the densified material, that is to say at the level of compressive strength and fracture. The desired level of densification is not necessarily the highest possible. Indeed for some end applications, it is preferable that the densified material has a low compressive strength and fracture.

If the compression height is too large, there is a risk that the profile 65 of the densified material is de-densifies after exiting the extruder 55.

As shown in Figure 5, the die 99 has, for example, according to a plane parallel to the extrusion axis, a straight profile (left of FIG 5), a bevelled profile (center of Figure 5) input and / or output, or a rounded profile input and / or output (to the right of Figure 5).

Advantageously, a special treatment or coating (not shown) of the surface S of the orifice of the die 99 allows a better sliding of the profile 65 of densified material from the die.

For example, in some configurations, the die 99 is closed during the filling phase the extruder 55. Also by way of example, the die 99 is itself equipped with a temperature regulation system ( not shown) to perform a heating or cooling of the section 65 coming out of the extruder 55.

Alternatively, it is possible to add more products that the film 5 (or the pieces of yarn) in the extruder 55, such as, for example, one or more thermoplastic materials, one or more additives binders, one or more compatibilizers additives, one or more anti-oxidant additives, one or more lubricant additives, one or more dispersant additives, one or more mineral fillers, one or more vegetable fillers, water, or more modifying additives of impacts, etc. .

Step 70 cutting

The profile 65 of the densified material is severed by a cutting device 1 1 1. 1 1 1 the cutting device comprises a cutting tool, for example turning and mounted in die tip (cutting head). The cutting tool preferably comprises rotating knives hard steel, with adjustable cutting angles. The cup

advantageously performed at room temperature using a jet 1 13 supply air, the air also serving to convey and cool the pellets 20 obtained.

Alternatively, the conformers (cooled or otherwise) or a cooling conveyor are placed at the outlet of the die 99. After an optional passage over a cooler (not shown), or the densified material profiles are incorporated in a tool granulator type of cutting (e.g. milling or mill-saw-circular) to obtain the granules 20.

After cutting, the granules 20 of densified material are optionally sieved. The fines are preferably returned to the input of the extruder 55 to be incorporated into the profile 65 of densified material produced.

The granules 20 of densified material are, for example packaged in bags to be stored or transported for later use. The granules 20 of densified material can also be temporarily stored in buffers silos.

The profile 65 of densified material and granules 20 of densified material

The profile 65 of densified material or granules 20 of densified material are ready to be easily incorporated in any method, as raw material.

We define a section 65 of black particular densified material and / or granules 20 of material densified black individuals, obtained from thermal transfer film having black ink.

profiles 65 colored individual is defined (green, red, yellow, blue, white, or gray in particular) and / or granules 20 of densified material colored individuals (green, red, yellow, blue, white, or gray in particular) obtained from films corresponding colors.

Alternatively, we define a material profile densified floréal obtained from thermal transfer films without selection color (embedded film can be all possible colors).

The densified material is not classified as hazardous under Directive

1999/45 / EC and complies with REACH.

The granules 20 are, for example block-shaped (Figure 6) or cylinder (figure 7).

The properties of the densified material granules obtained are advantageously substantially constant.

The main properties are given in Table 1 below.

The dimensional characteristics (length, diameter, width, size) are measured using a caliper.

The melting temperatures are measured by means of analysis by differential scanning calorimetry (English, Differential Scanning Calorimetry or DSC). Density is the mass of material contained in a given volume comprising the volume of interstitial air.

The humidity is measured according to EN 14346-A.

The ash content is measured according to ISO 3451 standard.

The fines content is measured by the following method. At least three samples of 2 kg minimum are taken. For each sample, the total weight is measured with a balance (minimum accuracy of 0.001 kg) and fine (having at least two dimensions less than 2 mm - measured by a caliper) are manually separated using d a small clamp. The slurry of fine is then measured with the same scale and the calculation of the mass ratio of the fine on total weight is achieved. The fines content to remember is the average of at least three results obtained from three different samples.

Nominal Unit

Granules 20 length L1 ≥ 2 mm

densified material

forme cylinders diameter DD1 ≥ 2 mm

Length L2 ≥2 mm

Granules 20

densified material width LL2 ≥2 mm

form pavers

≥2 mm height H2

Dimension 1 ≥2 mm

Granules 20

densified material Dimension 2

another form (in a direction

≥2 mm

perpendicular to that

of dimension 1)

fine mass rate

(Having at least two dimensions less than <20%

2 mm)

Melting point PET 245-265 ° C

Ash rate <5%

moisture content <3%

bulk density (of the bed of granules 20

> 120 kg/m3

uncompacted or packed)

Table 1

Example of production method according to the invention

The complex film rolls are thermal transfer film roll width L of between 10 and 120 mm

To feed the extruder 55, the roll is placed on a free axis. The film is unwound and is driven by the action of extruder screw 55.

The extruder 55 used is a twin screw extruder (twin screw) co-rotating. The screws have a length less than 200 mm, a nominal diameter less than 15 mm, and conjugate profiles (with each other) single net.

The die 99 has a single output, of rectangular section, and of length less than 20 mm LF.

The extrusion parameters are:

- screw speed of rotation of less than 50 turn / min,

- set temperature of the sheath heater 97 of less than 65 ° C,

In step 70 of cutting, a pair of scissors was used.

The granules obtained are 20 blocks of dimensions 4-5 mm x 3-5 mm x 2 to 3 mm and an average weight of 35 mg. The bed of granules 20 has a density (apparent) average between 200 and 400 kg / m 3 .

Step 80 Use the densified material

The profile 65 of densified material or granules 20 of densified material are used as raw material in industrial applications, for example in admixture with other thermoplastics in conventional plastics processing methods: injection, compression, extrusion, extrusion, thermoforming, compression, intrusion ... etc.

The profile 65 of densified material or granules 20 of densified material are mixed with other materials and incorporated through mixing equipment, e.g., slow mixers, rapid mixers, silos, barrel mixers, V or through dispensing equipment, for example volumetric or g m delighted narrow.

Exemple A

The granules 20 of densified material are used in admixture with other thermoplastics, for example polyolefins (HDPE, PP ...). Tests conducted by the Applicant have enabled to validate the feasibility of processing by extrusion and injection of a mixture containing, by weight, for example, 10% of granules 20 of densified material and 90% of polyolefin material.

The characteristics of the polymer blend (or compound) obtained (see Table 2 below) are equivalent to that of only polyolefins in terms of rheological properties, physico-chemical and mechanical.

Table 2 - Characterization of compound "granules 20 of material densified +

90% Feःd »

example B

The granules 20 of densified material are used in plastics as black masterbatch (or as a color masterbatch following references). The pellets 20 are thus a masterbatch recycled may substitute for virgin masterbatches.

Numerous tests conducted by the applicant have validated this use as masterbatch black or colored.

Tests have especially identified that the addition of granules 20 black densified material in a natural thermoplastic material allows to obtain a black coloring of quality since the granules comprise at least 0.5% by weight of the product color.

other examples

For example, the granules 20 of densified material (or the profile 65 of densified material) are used in the plastics industry as a filler within a thermoplastic matrix shaped by injection, compression, extrusion, extrusion, thermoforming, compression, intrusion, etc. .

According to another example, the granules 20 of densified material (or sections 65 of densified material) are used in the plastics industry as an additive in a mixture of thermoplastic initially little or not compatible so as to improve the compatibility of the blend components together. To illustrate, tests have shown that the pellets 20 through the ink they contain, improve compatibility between HDPE and PET a factor of 10 compared to a mixture without the additive.

According to another example, the granules 20 of densified material (or the profile 65 of densified material) are used in the plastics industry to modify the viscosity within a thermoplastic matrix shaped by injection, compression, extrusion, extrusion, thermoforming, compression, intrusion, ... etc.

According to another example, the granules 20 of densified material (or the profile 65 of densified material) are used as fillers or raw materials within a thermosetting matrix (e.g. shaping by compression, or by injection molding RIM) , an elastomeric matrix or a rubber based matrix.

According to another example, the granules 20 of densified material (or the profile 65 of densified material) are used in other sectors such as:

- costs or raw materials in the manufacture of concrete, cement, asphalt, bitumen, ceramic products, ... etc,

- raw materials in the manufacture of thermal and acoustic insulation,

- filling material or filling voids or

- raw material in the manufacture of rigging products.

According to a last example, the granules 20 of densified material (or the profile 65 of densified material) are used in plastics as release agents within a thermoplastic matrix shaped by injection, compression, extrusion, extrusion, thermoforming, compression, intrusion ... etc.

Advantages

Thanks to the characteristics described above, the invention provides an improved method of producing densified material directly usable in the form of granules 20 of densified material or one or more sections of densified material from waste complex films including thermal transfer film, while limiting the number of steps to promote recycling, as well as possible uses of the resultant densified material.

Through the use of at least one endless screw, it is possible, according to an advantageous embodiment, to feed the extruder 55 by the film 5 without shredding / prior grinding. It is further possible to incorporate directly the profile 65 of the densified material in processes for final application without the step 70 prior to cutting.

The method of the invention can transform and use films with a very high rate of inks, even when inked waste is used alone, and allows for example that these inks are used as binders in step compression.

Within the framework of his research, the Applicant has tested use granules 20 of densified material or profile 65 of densified material obtained in admixture with other thermoplastics. It turned out, for example, processing is technically feasible when the densified material in a suitable particle size, is mixed with other thermoplastic materials.

The method is particularly suited to thermal transfer film waste (presence of cardboard cores, very low thickness of the film, the film heavily inked).

The steps of separating the mandrels of the rolls, compressibility, possible cutting and use of the densified material obtained as raw material in a final application may be advantageously formed on the same production line.

The granules 20 of densified material have a particle size and a bulk density facilitating their packaging, transport and their implementation in conventional conversion processes in the plastics industry (injection, extrusion ...).

The densified material is usable in many applications, particularly as a mixture in polyolefin materials or other thermoplastic materials without loss of properties, incorporation rates up to 10% by weight of the densified material, or as as a black masterbatch, or colored, recycled substitutable blank masterbatches.

CLAIMS
1 .- A method for producing a densified material, the method comprising at least the steps of:
- obtaining a film (5) having at least a first layer (7) of plastic material, for example PET, and a second layer (9) of distinct composition of the first layer, e.g., ink, first layer (7) having a first melting temperature (T1), and obtaining pieces of such a film (5),

- compression of the film (5) obtained or film pieces (5) obtained through at least one die (99) of at least one extruder (55), and obtaining at least one profile (65) of material densified, the extruder (55) having at least one worm (95) rotating to urge the film (5) obtained or film pieces (5) obtained according to a screw axis (D2) with respect to the extruder (55), and

- optional cutting of the profile (65) to obtain granules (20) of densified material,

the compressing step being performed at a maximum compression temperature (Tm) of the film (5) obtained or film pieces (5) obtained, the maximum compression temperature (Tm) is lower than the first melting temperature (T1 ).

2.- Method according to claim 1, wherein the second layer (9) has a second melting temperature (T2) less than or equal to the first melting temperature (T1), preferably lower by at least 10 ° C, the temperature (Tm) of the compressing step being between the second melting temperature (T2) less than 60 ° C and the second melting temperature (T2) greater than 60 ° C, preferably between the second melting temperature ( T2) minus 35 ° C and the second melting temperature (T2) plus 35 ° C.

3.- Method according to claim 1 or 2, wherein the worm (95) comprises:

- at least one cutting element (105) for cutting the film (5) obtained or film pieces (5) obtained, and / or

- at least a portion (103) wherein the worm (95) has an internal diameter (DI) perpendicular to the screw axis (D2), the inner diameter (Dl) is growing according to the screw axis ( D2) for compressing, at the densification step, the film (5) obtained or film pieces (5) obtained.

4. A method according to any one of claims 1 to 3, wherein the worm (95) is part of a system with two conical extruder screws (55).

5. A method according to any one of claims 1 to 4, wherein the die (99) has a compression height between 1, 5 and 15.

6. A method according to any one of claims 1 to 5, wherein the extruder (55) defines a sleeve (97) through which the worm (95), the worm (95) having a nominal diameter ( DN), and threads (98) separated from the sleeve (97) by a distance (ES) greater than or equal to 0.001 times the nominal diameter (DN).

7. Method according to any one of claims 1 to 6, further comprising the steps of:

- obtaining the film (5) by unwinding a roll (1), the flow being produced by suction of the film (5) or by a direct drive or of the film (5) by the screw (95), and

- continuous feed of the extruder (55) the film (5).

8.- Installation for producing a densified material, the installation comprising:

- a source of a film (5) or film pieces (5), the film (5) having at least a first layer (7) of plastic material, for example PET, and a second layer (9) separate composition of the first layer (7), for example ink,

- at least one extruder (55) adapted to compress the film (5) or the film pieces (5), the extruder (55) having at least one die (99) output of at least one profile (65) densified material, and at least one worm (95) rotating to urge the film (5) or the film pieces (5) in a screw axis (D2) with respect to the die (99), the extruder (55) being adapted to carry out the compression at a maximum compression temperature (Tm) of the film (5) or film pieces (5), the maximum compression temperature (Tm) is lower than the first melting temperature (T1 ), and

- optionally at least one cutting device (1 1 1) adapted to produce granules (20) of densified material from the profile (65).

9. - Pellets (20) of densified material obtainable by a method according to any one of claims 1 to 7, a bed of said granules (20) of compacted material having a bulk density greater than 120 kg / m 3 , and the granules (20) of densified material each having a smaller dimension (DD1 or L1, LL2 or H2 or L2) greater than 2 mm.

10. - Use of at least one profile (65) of densified or granular material (20) of densified material obtained by a method according to any one of claims 1 to 7, the profile (65) or the granules (20 ) being used as:

at. dye to a thermoplastic material,

b. filler within a thermoplastic matrix,

c. raw material in the formulation of thermosetting,

d. raw material in a concrete, cement, asphalt, or a paint, e. raw material in the manufacture of dunnage products,

f. filling material or filling of an empty space,

g. release agent in a thermoplastic matrix,

h. compatibilizer in a mixture with thermoplastic materials to increase the compatibility of said materials with each other or

i. viscosity modifier in a thermoplastic matrix.