Title of Invention

AN INJECTION MOULDING MACHINE AND A METHOD OF MANUFACTURING AN ARTICLE BY USING THE SAME

Abstract ABSTRACT This invention relates to an improved injection moulding machine and a method of manufacturing an article by using the same. The machine involves providing an auxiliary screw barrel with hopper, in addition to the main screw barrel with hopper, for feeding a blend material consisting of raw materials with one or more colours, through a feeding ring having multiple passages. The moulded articles have finish like the natural material. 4 FEB 2005
Full Text FORM-2 THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE
Specification
(See section 10 and rule 13)
AN INJECTION MOULDING MACHINE AND A METHOD OF MANUFACTURING AN ARTICLE BY USING THE SAME
NILKAMAL PLASTICS 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 PAR [ICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.


This invention relates to an injection moulding machine and a method of manufacturing an article by using the same.
More particularly this invention relates to an injection moulding machine in which an secondary/auxiliary unit is provided, in addition to a main unit, for feeding an additional blended material having different colours and the blended material flow pattern of the main unit and the auxiliary unit and the metering and injection sequence of the blended material being controlled by a hydraulic system integrated with electrical/electronic circuit, so as to achieve natural material finish of the moulded article, such as wood finish, marble finish, granite finish or stone finish and the like.
This invention also provides a method of manufacturing the moulded articles having surface finishing of natural materials like wood marble, granite or stone, by using multi/two colours blends feeding using for injection moulding machine, according to this invention.
Due to light weight and other convenience use of the plastic furniture or other articles has now become very common. These articles are mass produced by injection moulding. These articles are generally manufactured in a single colour which is added in the raw material and mixed in a blender, forming a blend material which is fed through a hopper and screw barrel of an injection moulding machine, which is further provided with a shut off nozzle and a machine nozzle to inject the blend material into a mould.
Thus an existing injection moulding machine mainly comprises a Hopper, a Screw barrel, a shut off nozzle, a machine nozzle and a mould.


For manufacturing plastic moulded articles in more than one colour say in two colours, a double barrel injection moulding machine is connected to the main screw barrel after shut off nozzle, on the front end, near the tip of the screw.
By using this double barrel injection moulding machine, known in the prior art, the articles moulded, contain only thick bands of two distinct colours, but the finishing of natural materials like wood, marble, granite or stone cannot be achieved in the hitherto available moulding machines of the prior art, which are more preferred.
The main object of this invention is to provide an improved injection moulding machine which is capable of providing natural material finishing to the moulded articles.
Another object of this invention is to provide a method of manufacturing moulded articles, by using the injection moulding machine, according to this invention, by which the moulded articles produced contain finish wood, marble, granite or stone, so as to look alike natural material articles.
Accordingly this invention provides an injection moulding machine wherein the improvements being made by providing an auxiliary screw barrel with hopper, in addition to the main screw barrel with hopper, for feeding a blend material consisting of raw materials with one or more colours, through a feeding ring having multiple passages, provided between the metering zone and the compression zone of the main screw barrel, a hydraulic system integrated with electronic and electrical circuit forming a control system, for metering and injection sequence, for


achieving flow pattern of two or more colours, giving the moulded articles a finish resembling to the products of natural materials like wood, marble, granite, stone and the like.
Typically, the multiple passages of the said feeding ring are of the same diameter or varying diameters.
Typically, the number of passages can be varied/ reduced by blocking one or more passages by grub screws, as per requirement.
Typically, the said feeding ring is removably fitted so as to replace it by another feeding ring has multiple passages of different larger diameters for varying, increasing the size of the multiple passages.
According to another aspect of the invention there is provided a method of manufacturing moulded articles having finish alike the natural material products, by using the improved injection-moulding machine according to this invention comprising following steps:
a) preparing a blend of a first coloured raw materials with white or yellow raw materials by mixing in a blender;
b) preparing a blend of a second coloured raw materials having a colour different from the first by mixing in a blender;
c) feeding the first and the second blended materials separately through the main screw barrel [blend of step(a)] and the auxiliary screw barrel [blend of step(b)] the temperature of the two barrels being maintained in the range of 175° C to 250° C;
d) feeding/injecting the blended material of the auxiliary screw barrel, into the main screw barrel through feeding ring provided in the compression zone of the main screw barrel, just before


the measuring zone and shut off nozzle, the said blended material from the auxiliary screw barrel being injected in the compression zone of the main screw barrel, while the main screw moving backward for the refilling the blended material of step (a);
e) injecting the blended materials through the main screw, metering zone, shut off nozzle and machine nozzle into the mould;
f) controlling the metering and injection sequence with the help of hydraulic system integrated with electronic and electrical circuit for achieving flow pattern of two or more colours of blended materials very close to natural material colours;
g) after filling the mould and holding for a set time, cooling the mould by flowing cold water at temperature of 8°C to 30°C, through water flow channels;
h) after solidifying, ejecting out the moulded articles having finish alike the natural material and then repeating the moulding process cycle.
Typically, the method involves of manufacturing moulded articles as claimed wherein number of injection / refill strokes of the auxiliary barrel depends upon the colour pattern and the weight of the moulded article.
Further, in accordance with a preferred embodiment of this invention injection pressure for both the screw barrels is set in the range of 40% to 99% of hydraulic pressure of the injection moulding machine.


Typically, the blend material is fed through the main screw and auxiliary screw at a screw rotation speed of 1 to 99 RPM.
The invention will become more clear from the following description with reference to accompanying drawings wherein :
FIG. 1. shows in part sectional elevation, the arrangement of the various
components of an existing injection moulding machine;
FIG. 2. shows, the flow chart of the blend material used for moulding an
article, in the existing injection moulding machine of figure 1;
FIG. 3. shows, in part sectional elevation, the arrangement of various
components and systems of the improved injection moulding machine,
according to an embodiment of this invention; and
FIG.4. shows, the flow chart, of the two blend materials, used for
moulding an article having finish alike natural material, in the improved
injection moulding machine, according to this invention.
Referring to Figs. 1 and 2, which relates to prior art injection moulding machine and the flow chart of the blend material for the moulding of an article. The injection moulding machine 10 is well known in the prior art and hence is not described herein. By manufacturing an article by the existing injection moulding machine, the blend material prepared by blending the raw materials, mixed with colours is fed into a hopper 'h' of the machine which passes through a screw barrel to shut off nozzle and through the machine nozzle is injected into the mould to obtain an article in single colour. Similarly by using a standard double barrel injection moulding machine of the prior art, in which a second blend material with another colour is fed through another auxiliary barrel, connected to main


barrel, after the shut off nozzle, on the front end, near the screw tip, an article with thick bands of two distinct colours is moulded out.
Now referring to Figs. 3 and 4 which relates to the improved injection moulding machine, of this invention and flow chart of feeding blend materials for moulding out articles having finish like natural materials such as wood, marble, granite, stone, and the like. Improvements in the injection moulding machine according to this invention mainly resides in providing an auxiliary hopper 'ah' and screw barrel in addition to main hopper 'h' and screw barrel for feeding two blend materials, say for example raw materials like yellow or white are mixed in a blender for about 10 minutes forming a blend material 'A' to be fed through the main hopper and screw barrel. Again raw materials like brown are mixed in a blender for about 10 minutes forming another blend material 'B' to be fed by auxiliary hopper and screw barrel.( Refer to flow chart shown in Fig.4) Blend materials 'A' and 'B' pass through respective screw and barrel gaps of screw barrels. The blend material 'B' fed through the auxiliary unit/screw barrel is mixed into the blend material 'A' in the main screw barrel, in its compression zone that is before nozzle shut off and before the metering zone of the main screw barrel. The blend material 'B' from the auxiliary screw barrel is fed into the compression zone of main screw barrel through a feeding ring, located between the metering zone and compression zone of the main screw barrel, before the shut off nozzle. The feeding ring is provided with a multiple passages of same or various diameters. The number of passage can be reduced or varied with the help of grub screws, removably provided in some of the passages in order to close them so as to reduce the number of effective passages in the feeding ring (7.8).




Further the feeding ring is replacable and by changing a feeding ring having passages of different diameters, passage size/diameter is changed.
Further the metering and injection sequence according to this invention is controlled by providing a hydraulic system integrated with the electonic and electrical circuit. Thus with the combination of colours mixed in the two blend materials 'A' & 'B' by varying the number and size of the passages of the feeding ring and by controlling the metering and injection sequences, the unique patterns similar to natural materials such as wood, marble, granite or stone are achieved in the moulded articles. Thus the improved injection moulding machine, according to this invention gives the flow pattern of two or more colours to achieve the finish of the moulded articles alike the finish of articles made of natural materials.
The operation of the improved injection moulding machine is as follows :
1. The main screw in its barrel is fully in forward position, such as after the completion of the injection sequence.
2. The main screw starts rotating and moving backward for refilling the blend material 'A' from the main hopper.
3. While the main screw moves back for refilling, the auxiliary screw in its barrel intermittently or continuously inject the material 'B' into the compression zone of the main screw barrel 'A' through the variable passages feeding ring. The rate of injection, the time of injection/stop time, total feed amount, the colours/shades of the blend materials and the concentration of the master batch within the blend materials which is fully


controlled by the hydraulic system integrated with electronic and electrical circuit gives various possibilities to produce various shade effects in the moulded product. It is possible to completely discharge the blend material of auxiliary screw barrel and once again refill and inject. Delay sequence of the auxiliary screw barrel is completed.
4. Once the refill of the main screw barrel is complete, the injection, refill, delay sequence of the main screw and the auxiliary screw is also completed.
5. The main screw is now ready for injection along with the input from auxiliary screw barrel.
At the end, the main screw is once again in the fully forward position.
For manufacturing moulded articles raw materials are blended in a blender and fed through the main and auxiliary screw barrels as described above. The barrel temperatures are set between 175°C to 250°C. Injection pressure for both the screw barrels, is set in the range of 40% to 99% of the hydraulic pressure of the injection moulding machine, screw speed is set from 1 to 99 RPM.
During main screw barrel refill operation, feeding of blend material from auxiliary screw barrel in main screw barrel 'takes place as per set timing (Injection, Refill, Delay).
The number of injection/refill strokes of auxiliary screw barrel depends upon, colour, pattern and weight required, of the moulded article. Blend materials 'A' & 'B' flow to mould via main screw barrel through material zone, shut off nozzle and machine nozzle. After refilling an holding, the


material solidifies on cooling by following cooling water through flow cannels, cooling water temperature is set between 8°C to 30°C. After solidifying moulded article falls down automatically with the help of ejection pin. After dropping the article machine closes and the cycle is repeated.


We Claim:
1. An injection moulding machine wherein the improvements being made by providing an auxiliary screw barrel with hopper, in addition to the main screw barrel with hopper, for feeding a blend material consisting of raw materials with one or more colours, through a feeding ring having multiple passages, provided between the metering zone and the compression zone of the main screw barrel, a hydraulic system integrated with electronic and electrical circuit forming a control system, for metering and injection sequence, for achieving flow pattern of two or more colours, giving the moulded articles a finish resembling to the products of natural materials like wood, marble, granite, stone and the like.
2.An improved injection-moulding machine as claimed in claim-1 wherein the multiple passages of the said feeding ring are of the same diameter or varying diameters.
3.An improved injection moulding machine as claimed in claims-1 or 2 wherein the number of passages can be varied/ reduced by blocking one or more passages by grub screws, as per requirement.
4.An improved injection moulding machine as claimed in claim-1 wherein the said feeding ring is removably fitted so as to replace it by another feeding ring having multiple passages of different larger diameters for varying, increasing the size of the multiple passages.
5. A method of manufacturing moulded articles having finish alike the natural material products, by using the improved injection-moulding machine as claimed in claims 1 to4 comprising following steps:


a) preparing a blend of a first coloured raw materials with white or
yellow raw materials by mixing in a blender;
b) preparing a blend of a second coloured raw materials having a colour different from the first by mixing in a blender;
c) feeding the first and the second blended materials separately through the main screw barrel [blend of step(a)] and the auxiliary screw barrel [blend of step(b)] the temperature of the two barrels being maintained in the range of 175° C to 250° C;
d) feeding/injecting the blended material of the auxiliary screw barrel, into the main screw barrel through feeding ring provided in the compression zone of the main screw barrel, just before the measuring zone and shut off nozzle, the said blended material from the auxiliary screw barrel being injected in the compression zone of the main screw barrel, while the main screw moving backward for the refilling the blended material of step (a);
e) injecting the blended materials through the main screw, metering zone, shut off nozzle and machine nozzle into the mould;
f) controlling the metering and injection sequence with the help of hydraulic system integrated with electronic and electrical circuit for achieving flow pattern of two or more colours of blended materials very close to natural material colours;
g) after filling the mould and holding for a set time, cooling the mould by flowing cold water at temperature of 8°C to 30°C, through water flow channels;
h) after solidifying, ejecting out the moulded articles having finish alike the natural material and then repeating the moulding process cycle.


6.A method of manufacturing moulded articles as claimed in claim 5 wherein number of injection / refill strokes of the auxiliary barrel depends upon the colour pattern and the weight of the moulded article.
7.A method of manufacturing moulded articles as claimed in claim-5, wherein injection pressure for both the screw barrels is set in the range of 40% to 99% of hydraulic pressure of the injection moulding machine.
8.A method of manufacturing moulded articles as claimed in claim-5, wherein blend material is fed through the main screw and auxiliary screw at a screw rotation speed of 1 to 99 RPM.
9. An improved injection-moulding machine substantially as herein described and illustrated in Figs. 3 & 4 of the drawings accompanying this specification.
10. A method of manufacturing moulded articles having finish like the natural material products, by using an improved injection moulding machine, as claimed in any of the claims 1 to 4, substantially as herein described.
Dated this 4th day of February 2005.

ofRKDewan&Co., Applicants' Patent Attorney
13

Documents:

1156-mum-2003-abstract(04-02-2005).doc

1156-mum-2003-abstract(04-02-2005).pdf

1156-mum-2003-abstract(complete)-(4-2-2005).pdf

1156-mum-2003-abstract(granted)-(11-4-2008).pdf

1156-mum-2003-abstract.doc

1156-mum-2003-abstract.pdf

1156-mum-2003-cancelled pages(17-03-2008).pdf

1156-mum-2003-claims(complete)-(4-2-2005).pdf

1156-mum-2003-claims(granted)-(11-4-2008).pdf

1156-mum-2003-claims(granted)-(17-03-2008).doc

1156-mum-2003-claims(granted)-(17-03-2008).pdf

1156-mum-2003-claims.doc

1156-mum-2003-claims.pdf

1156-mum-2003-correspondence(17-03-2008).pdf

1156-mum-2003-correspondence(17-3-2008).pdf

1156-mum-2003-correspondence(ipo)-(11-04-2008).pdf

1156-mum-2003-correspondence(ipo)-(2-5-2008).pdf

1156-mum-2003-correspondence(ipo).pdf

1156-mum-2003-correspondence.pdf

1156-mum-2003-description(complete)-(4-2-2005).pdf

1156-mum-2003-description(granted)-(11-4-2008).pdf

1156-mum-2003-description(granted).doc

1156-mum-2003-description(granted).pdf

1156-mum-2003-drawing(04-02-2005).pdf

1156-mum-2003-drawing(complete)-(4-2-2005).pdf

1156-mum-2003-drawing(granted)-(11-4-2008).pdf

1156-mum-2003-drawing(provisional)-(4-11-2003).pdf

1156-mum-2003-drawing.pdf

1156-mum-2003-form 1(04-11-2003).pdf

1156-mum-2003-form 1.pdf

1156-mum-2003-form 18(05-05-2006).pdf

1156-mum-2003-form 18.pdf

1156-mum-2003-form 2(cancelled)-4-feb-2005.pdf

1156-mum-2003-form 2(complete)-(4-2-2005).pdf

1156-mum-2003-form 2(granted)-(11-4-2008).pdf

1156-mum-2003-form 2(granted)-(17-03-2008).doc

1156-mum-2003-form 2(granted)-(17-03-2008).pdf

1156-mum-2003-form 2(granted).doc

1156-mum-2003-form 2(granted).pdf

1156-mum-2003-form 2(provisional).pdf

1156-mum-2003-form 2(title page)-(complete)-(4-2-2005).pdf

1156-mum-2003-form 2(title page)-(granted)-(11-4-2008).pdf

1156-mum-2003-form 2(title page)-(provisional)-(4-11-2003).pdf

1156-mum-2003-form 2(title page).pdf

1156-mum-2003-form 26(04-11-2003).pdf

1156-mum-2003-form 3(04-11-2003).pdf

1156-mum-2003-form 3.pdf

1156-mum-2003-form 4(15-12-2004).pdf

1156-mum-2003-form 4.pdf

1156-mum-2003-form 5(04-02-2005).pdf

1156-mum-2003-form 5.pdf

1156-mum-2003-power of attorney.pdf

abstract1.jpg


Patent Number 218748
Indian Patent Application Number 1156/MUM/2003
PG Journal Number 31/2008
Publication Date 01-Aug-2008
Grant Date 11-Apr-2008
Date of Filing 04-Nov-2003
Name of Patentee NILKAMAL PLASTICS LIMITED
Applicant Address
Inventors:
# Inventor's Name Inventor's Address
1 PAREKH HITEN
PCT International Classification Number B 29 C 45/66
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA