FORM-2
THE PATENTS ACT, 1970
(39 of 1970]
&
THE PATENTS RULES, 2006
COMPLETE
Specification
(See Section 10 and Rule 13)
AN INJECTION MOULDING APPARATUS AND PROCESS
NILKAMAL LIMITED,
an Indian Company,
of Survey No.354/2 & 354(3),Near Rakholi Bridge,
Silvassa-Khanvel Road,Village Vasona ,Silvassa(D & NH),
India
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF INVENTION
The invention relates to an injection moulding machine and the method of manufacturing an article by using the same.
BACKGROUND OF THE INVENTION
Plastic moulded articles/ product are generally manufactured by injection moulding. Injection moulding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Typically, material is fed into a heated barrel where they are melted and mixed and forced into a mould cavity so as to cool and harden to the configuration of the mould cavity.
The use of plastic articles/ product has been increasing as they are light in weight. However, presently the plastic article/ product are generally manufactured of single colour. This is achieved by mixing colour to the raw material in a blender and thereafter the blended material is injected into a mould by means of a screw barrel, a shut off nozzle and a machine nozzle.
In order to manufacture plastic moulded article/ product of more than one colour, separate injection barrel is connected after the shut off nozzle. This is carried out in a double barrel injection moulding machine. However, using the plastic moulded article/ product contain thick bands/striations of distinct colours.
Thus, the prior art helps in manufacturing plastic moulded article/ product of single colour or having striations of distinct colours. They cannot be used to

produce plastic moulded article/ product having finishing of natural materials like wood, marble, granite, stone and the like. Hence, there was felt a need for a moulding machine and method which can produce a plastic moulded article/ product having finishing of natural materials.
OBJECT OF THE INVENTION
An object of the present invention is to provide an injection moulding machine which is capable of producing plastic moulded article/ product having finishing of natural materials.
Another object of the present invention is to provide plastic moulded article/ product having better aesthetic appearance.
Yet another object of the present is to provide an injection moulding machine which is simple in construction.
Still another object of the present invention is to provide an injection moulding machine which is efficient.
An added object of the present invention is to provide an injection moulding machine which is cost effective.
An additional object of the present invention is to provide an injection moulding machine which is easy to install.

SUMMARY OF THE INVENTION
In accordance with the present invention there is provided an injection moulding apparatus for moulding an article from a molten raw material, the apparatus comprising:
> an injection unit having a main transfer unit and at least one auxiliary transfer unit;
> a die head cooperating with the main transfer unit and the at least one auxiliary transfer unit, the die head having a back plate, a mid plate and a top plate; and
> a clamping unit cooperating with the die head through a nozzle, the clamping unit having a mould and mechanism for sealing the mould, the nozzle adapted to inject the molten raw material into the mould.
Typically, the main transfer unit and the at least one auxiliary transfer unit has a main screw and barrel assembly and at least one auxiliary screw and barrel assembly respectively, the main screw and barrel assembly and the at least one auxiliary screw and barrel assembly is adapted to receive the molten raw material from a main hopper and at least one auxiliary hopper respectively,
Typically, a main screw and barrel assembly and at least one auxiliary screw and barrel assembly are adapted to mix the molten raw material with at least one colour.
Typically, the main transfer unit has a metering zone, the die head being located after the metering zone.

Typically, the top plate is provided with a first set of holes located in first radius, a second set of holes located in second radius and a third set of holes located in third radius, the first set of holes being adapted to receive molten raw material from the main transfer unit, the second set of holes and the third set of holes being adapted to receive molten raw material from the at least one auxiliary transfer unit.
Typically, the first set of holes is located in a circular passage and each of the holes in the second set of holes and the third set of holes located with arcuate grooves.
Typically, the circular passage is connected to each of the arcuate grooves by means of connecting channels.
Typically, the back plate and the mid plate are provided with a fourth set of holes, a fifth set of holes and a sixth set of holes along a fourth radius, a fifth radius and a sixth radius respectively, the fourth radius, the fifth radius and the sixth radius are equal to the first radius, the second radius and the third radius respectively.
Typically, the fourth set of holes are aligned with the first set of holes, the fifth set of holes cooperates with the arcuate grooves of the second set of holes and a sixth set of holes cooperates with the arcuate grooves of the third set of holes.
Typically, the sets of holes are of same or varying dimensions.
Typically, the main screw and barrel assembly and the at least one auxiliary screw is controlled by a control system, the control system having a hydraulic system integrated with an electronic and/or electrical circuit adapted to monitor the injection sequence, the flow patterns of the molten

raw material through the main screw and barrel assembly and the at least one auxiliary screw and barrel assembly.
Typically, the main screw and barrel assembly and the at least one auxiliary screw and barrel assembly are adapted to inject the molten raw material at an injection pressure in the range of 40% to 99% of hydraulic pressure.
Typically, the main screw and barrel assembly and the at least one auxiliary screw and barrel assembly has a rotational speed of 1 to 99 RPM.
Typically, the clamping unit is hydraulically operated.
Typically, the clamping unit is provided with an ejector cylinder for removal of the article from the mould.
Typically, the article is cooled in the mould to a temperature of 8° C to 30° C by circulation of cooling water through water flow channels.
Typically, the mould is attached to a fixed platen and is closed by means of a moving platen, the moving platen is adapted to be moved to a predetermined position by means of a plurality of tie bars and at least one toggle plate.
Typically, the clamping unit is provided with at least one door for inspection.
In accordance with the present invention there is provided a method for moulding an article from a molten raw material, the method comprising the steps of:
> blending a group of raw material with at least one colour master batch;
> feeding a part of the mixture of material blended with at least one master batch colour to a main hopper and feeding the

remaining of the mixture of raw material blended with at least one second colour to at least one auxiliary hopper;
> heating and causing the molten raw material to pass through a main screw and barrel assembly and at least one auxiliary screw and barrel assembly;
> allowing the molten raw material to flow from the main screw and barrel assembly and the at least one auxiliary screw and barrel assembly to pass through a die head into a nozzle;
> injecting the molten raw material through the nozzle into a mould to form the article; and
> cooling the article in the mould and withdrawing the article from the mould.
Typically, the step of allowing the molten raw material to flow is controlled by means of at least one electronic controller.
BRIEF DESCRIPTION OF THE FIGURES
Other aspects of the invention will become apparent by consideration of the accompanying drawing and their description stated below, which is merely illustrative of a preferred embodiment of the invention and does not limit in any way the nature and scope of the invention.
Figure 1 illustrates the elevation view of the clamping unit of the injection moulding machine of the present invention;
Figure 2 illustrates the top view of the clamping unit of the injection moulding machine of the present invention;

Figure 3 illustrates the elevation view of the injection unit of the injection
moulding machine of the present invention;
Figure 4 illustrates the side view of the injection unit of the injection
moulding machine of the present invention;
Figure 5 illustrates the top view of the injection unit of the injection
moulding machine of the present invention;
Figure 6 illustrates the front view of the die head in accordance with the
present invention;
Figure 7 illustrates the side view of the die head in accordance with the
present invention;
Figure 8 illustrates of the back plate of the die head in accordance with the
present invention;
Figure 9 illustrates the side view of the back plate of the die head in
accordance with the present invention;
Figure 10 illustrates the front view of the mid plate of the die head in
accordance with the present invention;
Figure 11 illustrates the side view of the mid plate of the die head in
accordance with the present invention;
Figure 12 illustrates the front view of the top plate of the die head in
accordance with the present invention;
Figure 13 illustrates the side view of the top plate of the die head in
accordance with the present invention; and
Figure 14 illustrates the flow of the raw material to the mould through the
injection unit.

DETAILED DESCRIPTION
The invention will now be described with reference to the accompanying drawings which do not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.
The process of moulding of the present invention is carried out in a moulding machine having a clamping unit (10), shown in figure 1 and figure 2, and an injection unit (32), shown in figure 3, figure 4 and figure
5.
The clamping unit (10), mounted on a damping, unit base (11), comprises at least one hydraulic cylinder (12), at least four tie bars (14) each having two tie bar nuts (16), a moving platen (18), a fixed platen (20), a toggle plate (22), at least one toggle (24) and a mould (not particularly shown in the figure). The mould (not particularly shown in tf>e figure) is attached to the fixed platen (20) on one side and is closed by means of the moving platen (18). The moving platen (18) is moved from a mould closing position to a mould opening position by means of the tie bafs (14) and the toggle plate (22). The clamping unit (10) is further provided with a front door (26) and a rear door (28) to facilitate inspection and maintenance work. An ejector cylinder (30) is provided to help in ejecting the moulded article from the mould (not particularly shown in the figure).
The injection unit (32), mounted on a injection unit base (33), comprises of a main hopper (H) with a main screw and barrel assembly (M), a first auxiliary hopper (HI) with a first auxiliary screw and barrel (Al) and a second auxiliary hopper (H2) with a second auxiliary screw and barrel (A2).

The injection unit (32) further comprises a controller (34), a die head (36) and a nozzle (38) having a nozzle body (37). The nozzle (38) is provided within a nozzle body adapter (39) for connecting the nozzle (38) to the die head (36).
The main hopper (H) with a main screw and barrel assembly (M), the first auxiliary hopper (HI) with the first auxiliary screw and barrel assembly (Al) and the second auxiliary hopper (H2) with the second auxiliary screw and barrel assembly (A2) helps in feeding the molten raw material mixed with one or more colours. Typically, the molten raw material is fed through the main screw and barrel assembly (M), first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2) at a screw rotation speed of 1 to 99 RPM. The main screw and barrel assembly (M) is provided with a metering zone (40). The raw material from the main screw and barrel assembly (M), the first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2) is injected into the mould through the die head (36). Typically, the injection pressure for the main screw and barrel assembly (M), the first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2) is set in the range of 40% to 99% of hydraulic pressure of the injection moulding machine.
The main screw and barrel assembly (M), the first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2) is controlled by a control system (not shown in figure). The control system is provided with a hydraulic system which is integrated with an electronic and/or electrical circuit for monitoring the injection sequence and the flow

patterns of the molten raw material through the main screw and barrel assembly (M)} the first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2).
The die head (36), shown in figure 6 and figure 7, is provided with plurality of passages and typically has 3 parts - a back plate (42), shown in figure 8 and figure 9, a mid-plate (44), shown in figure 10 and figure 11, and a top plate (46), shown in figure 12 and figure 13. The die head (36) is located after the metering zone (40) of the main screw barrel assembly (M). The top plate (46) of the die head (36) is typically provided with a first set of holes (25a) in circular passage (35c) in a first radius (Rl), a second set of holes (27a) in a second radius (R2) and a third set of holes (29a) in a third radius (R3). The circular passage (35c) is connected to the second set of holes (27a) by a connecting channel (35a) while to the third set of holes (29a) by a connecting channel (35b). The raw material from the main screw and barrel assembly (M) flows through the groove (35c) and first set of holes (25a), the raw material from the first auxiliary screw and barrel assembly (Al) flows through the groove (31a) and the second set of holes (27a) and the raw material from the second auxiliary screw and barrel assembly (A2) flows through groove (31b) and the third set of holes (29a). The second set of holes (27a) in the second radius (R2) is provided with arcuate groove (31a) while the third set of holes (29a) in the third radius (R3) is provided with openings (31b). The first set of holes (25a), the second set of holes (27a) and the third set of holes (29a) are of the same dimension or of varying dimensions. The back plate (42) and the mid plate (44) of the die head (36) is typically provided with a forth set of holes (25b) in a fourth radius (R4), a fifth set of holes (27b) in a fifth radius (R5) and a sixth set of holes (29b) in

a sixth radius (R6). The first radius (Rl) is equal to the fourth radius (R4), the second radius is equal to the fifth radius (R5) and the third radius (R3) is equal to the sixth radius (R6). The first set of holes (25a) of the top plate (46) and the fourth set of holes (25b) of the back plate (42) are typically of the same dimensions. The fourth set of holes (25b), the fifth set of holes (27b) and the sixth set of holes (29b) are of the same dimension or of varying dimensions. The first set of holes (25a) of the top plate (46) is aligned with the fourth set of holes (25b) of the back plate (42) and the mid plate (44) to form a first passage. The fifth set of holes (27b) and the sixth set of holes (29b) of the back plate (42) and the mid plate (44) are aligned with the arcuate groove (31a) and the opening (31b) of the top plate (46) respectively to form a second passage and a third passage for the raw material. The first set of holes (25a), the second set of holes (27a), the third set of holes (29a), the fourth set of holes (25b), the fifth set of holes (27b) and the sixth set of holes (29b) are of same or varying dimensions.
The number of passages for the raw material, the variation in the diameter of the channel (not shown in figure) leading from the main screw and barrel assembly (M), the channel (41) leading from the first auxiliary screw and barrel assembly (Al) and the channel (43) leading from the second auxiliary screw and barrel assembly (A2) creates streaks and flow of the colours of the main screw and barrel assembly (M), the first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2) on the moulded article/product so as to resemble finishing of natural materials such as wood, marble, granite, stone and the like. The number of passages can be varied/reduced by blocking one or more passages by grub screws as per requirement. Alternatively, the die head (36) can be made with various

combinations by varying the number of passages, varied diameter of the channel from the main screw and barrel assembly (M), the channel (41) from the first auxiliary screw and barrel assembly (Al) and the channel (43) from the second auxiliary screw and barrel assembly (A2) to flow independently in the desired combinations so as to create the desired flow patterns.
The controller (34) is typically a hydraulic system. The controller (34) is integrated with electronic and electrical circuits forming a control system for monitoring the injection sequence, for achieving flow patterns of two or more colours in the main screw and barrel assembly (M), the first auxiliary screw and barrel assembly (Al) and the second auxiliary screw and barrel assembly (A2) thereby giving the moulded articles a finish resembling natural materials like wood, marble, granite, stone and the like.
Figure 14 illustrates the flow of the raw material to the mould through the main screw and barrel assembly (M) and the auxiliary screw and barrel assemblies Al and A2. The molten raw material is fed into the main hopper (H), the first auxiliary hopper (HI) and the second auxiliary hopper (H2) where from the raw material flows through the main screw and barrel assembly (M) and the auxiliary screw and barrel assemblies Al and A2. The molten raw material allowed to flow through the main screw and barrel assembly (M) and the auxiliary screw and barrel assemblies Al and A2 are blended with distinct colours. The controller (34) is adapted to control the flow of the raw material through the channel (not shown in figure) from the main screw and barrel assembly (M), the channel (41) from the first auxiliary screw and barrel assembly (Al) and the channel (43) from the second auxiliary screw and barrel assembly (A2) to the die head (36). The

amount of raw material flowing from the main screw and barrel assembly (M) is metered in the metering zone of the main screw and barrel assembly (M). The raw material from the auxiliary screw and barrel assemblies Al and A2 and the raw material from the metering zone of the main screw and barrel assembly (M) are allowed to flow through the multiple passages of the top plate (46), the mid plate (44) and the back plate (42) of the die head (36). The molten raw materials from the main screw and barrel assembly (M) and the auxiliary screw and barrel assemblies Al and A2 mixes and is injected into the mould (not particularly shown in the figure) through the nozzle (38) so as to provide the moulded article/product with finishing of natural materials such as wood, marble, granite, stone and the like. The moulded article is allowed to cool to a temperature in the range of 8° C to 30° C by circulation of cooling water through water flow channels.
TECHNICAL ADVANTAGES
The product and process as described herein above helps in manufacturing article/product having finishing resembling that of natural materials. Further, the present invention helps in manufacturing article/product having better aesthetic appearance.
Wherever a range of values is specified, a value up to 10% below and above the lowest and highest numerical value respectively, of the specified range, is included in the scope of the invention.
In view of the wide variety of embodiments to which the principles of the present invention can be applied, it should be understood that the illustrated

embodiments are exemplary only. The numerical values given of various physical parameters and dimensions are only approximations and it is envisaged that the values higher or lower than the numerical values assigned to the parameters, dimensions and quantities fall within the scope of the invention.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim:
1. An injection moulding apparatus for moulding an article from a molten raw material, said apparatus comprising:
> an injection unit having a main transfer unit and at least one
auxiliary transfer unit;
> a die head cooperating with said main transfer unit and said at least one auxiliary transfer unit, said die head having a back plate, a mid plate and a top plate; and
> a clamping unit cooperating with said die head through a nozzle, said clamping unit having a mould and mechanism for sealing the mould, said nozzle adapted to inject said molten raw material into said mould.

2. The injection moulding apparatus as claimed in claim 1, wherein said main transfer unit and said at least one auxiliary transfer unit has a main screw and barrel assembly and at least one auxiliary screw and barrel assembly respectively, said main screw and barrel assembly and said at least one auxiliary screw and barrel assembly is adapted to receive the molten raw material from a main hopper and at least one auxiliary hopper respectively.
3. The injection moulding apparatus as claimed in claim 2, wherein a main screw and barrel assembly and at least one auxiliary screw and barrel assembly are adapted to mix the molten raw material with at least one colour.

4. The injection moulding apparatus as claimed in claim 1, wherein said main transfer unit has a metering zone, said die head being located after said metering zone.
5. The injection moulding apparatus as claimed in claim 1, wherein said top plate is provided with a first set of holes located in first radius, a second set of holes located in second radius and a third set of holes located in third radius, said first set of holes being adapted to receive molten raw material from said main transfer unit, said second set of holes and said third set of holes being adapted to receive molten raw material from said at least one auxiliary transfer unit.
6. The injection moulding apparatus as claimed in claim 5, wherein said first set of holes is located in a circular passage and each of the holes in said second set of holes and said third set of holes located with arcuate grooves.
7. The injection moulding apparatus as claimed in claim 5, wherein said circular passage is connected to each of said arcuate grooves by means of connecting channels.
8. The injection moulding apparatus as claimed in claim 1, wherein said back plate and said mid plate are provided with a fourth set of holes, a fifth set of holes and a sixth set of holes along a fourth radius, a fifth radius and a sixth radius respectively, said fourth radius, said fifth radius and said sixth radius are equal to said first radius, said second radius and said third radius respectively.
9. The injection moulding apparatus as claimed in claim 8, wherein said fourth set of holes/channel are aligned with said first set of holes, said

fifth set of holes cooperates with the arcuate grooves of the second set of holes and a sixth set of holes cooperates with the arcuate grooves of the third set of holes.
10.The injection moulding apparatus as claimed in claim 5 and claim 8, wherein said sets of holes are of same or varying dimensions.
11. The injection moulding apparatus as claimed in claim 3, wherein said main screw and barrel assembly and said at least one auxiliary screw is controlled by a control system, said control system having a hydraulic system integrated with an electronic and/or electrical circuit adapted to monitor the injection sequence, the flow patterns of the molten raw material through said main screw and barrel assembly and said at least one auxiliary screw and barrel assembly.
12.The injection moulding apparatus as claimed in claim 3, wherein said main screw and barrel assembly and said at least one auxiliary screw and barrel assembly are adapted to inject the molten raw material at an injection pressure in the range of 40% to 99% of hydraulic pressure.
13.The injection moulding apparatus as claimed in claim 3, wherein said main screw and barrel assembly and said at least one auxiliary screw and barrel assembly has a rotational speed of 1 to 99 RPM.
14.The injection moulding apparatus as claimed in claim 1, wherein said clamping unit is hydraulically operated.
15. The injection moulding apparatus as claimed in claim 1, wherein said clamping unit is provided with an ejector cylinder for removal of the article from said mould.

16. The injection moulding apparatus as claimed in claim 1, wherein said the article is cooled in said mould to a temperature of 8° C to 30° C by circulation of cooling water through water flow channels.
17. The injection moulding apparatus as claimed in claim 1, wherein said mould is attached to a fixed platen and is closed by means of a moving platen, said moving platen is adapted to be moved to a predetermined position by means of a plurality of tie bars and at least one toggle plate.
18.The injection moulding apparatus as claimed in claim 1, wherein said clamping unit is provided with at least one door for inspection.
19. A method for moulding an article from a molten raw material, said method comprising the steps of:
> blending a group of raw material with at least one colour master batch;
> feeding a part of the mixture of material blended with at least one master batch colour to a main hopper and feeding the remaining of the mixture of raw material blended with at least one second colour to at least one auxiliary hopper;
> heating and causing the molten raw material to pass through a main screw and barrel assembly and at least one auxiliary screw and barrel assembly;
> allowing the molten raw material to flow from the main screw and barrel assembly and the at least one auxiliary screw and barrel assembly to pass through a die head into a nozzle:
> injecting the molten raw material through the nozzle into a mould to form the article; and

> cooling the article in the mould and withdrawing the article from the mould.
20. The method as claimed in claim 19, wherein said step of allowing the molten raw material to flow is controlled by means of at least one electronic controller.