GB2139549A - Injection moulding - Google Patents

Injection moulding Download PDF

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Publication number
GB2139549A
GB2139549A GB08312934A GB8312934A GB2139549A GB 2139549 A GB2139549 A GB 2139549A GB 08312934 A GB08312934 A GB 08312934A GB 8312934 A GB8312934 A GB 8312934A GB 2139549 A GB2139549 A GB 2139549A
Authority
GB
United Kingdom
Prior art keywords
plastics material
moulding
mould
external pressure
valve member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08312934A
Other versions
GB8312934D0 (en
Inventor
James Watson Hendry
Geoffrey David Gahan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB08312934A priority Critical patent/GB2139549A/en
Publication of GB8312934D0 publication Critical patent/GB8312934D0/en
Publication of GB2139549A publication Critical patent/GB2139549A/en
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/1703—Introducing an auxiliary fluid into the mould
    • B29C45/174—Applying a pressurised fluid to the outer surface of the injected material inside the mould cavity, e.g. for preventing shrinkage marks
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
    • B29C44/04—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles consisting of at least two parts of chemically or physically different materials, e.g. having different densities
    • B29C44/0446—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles consisting of at least two parts of chemically or physically different materials, e.g. having different densities by increasing the density locally by compressing part of the foam while still in the mould
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/56—Means for plasticising or homogenising the moulding material or forcing it into the mould using mould parts movable during or after injection, e.g. injection-compression moulding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
    • B29C45/57—Exerting after-pressure on the moulding material
    • B29C45/572—Exerting after-pressure on the moulding material using movable mould wall or runner parts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/1703—Introducing an auxiliary fluid into the mould
    • B29C45/1704—Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles

Abstract

The invention concerns the production of an injection moulding which may have an internal cavity 21 or porous core (50), Fig. 7, not shown formed by the injection of a fluid within the plastics material simultaneously to the introduction of the plastics material into the mould space. Before opening the mould, there is applied at at least one selected position, an external pressure on one surface 23 of the plastics material which moves the plastics material at that position inwardly of the moulding away from the adjacent mould surface 26, the external pressure being maintained until the plastics material is self-supporting. The pressure may be applied by the introduction of a fluid 32 between the plastics material and the mould surface, or mechanically (Figs. 3 to 7, not shown). <IMAGE>

Description

SPECIFICATION Injection Moulding and Mouldings Produced Thereby This invention relates to a process and apparatus for injection moulding and mouldings produced thereby.
Our other British Patent Application filed today describes a method of injection moulding which involves injecting a fluid under pressure into the plastics material simultaneously to the introduction of the plastics material into a mould space for the creation of a pressurised mass of fluid or a porous core within the plastics material for the dual purpose of reducing the weight of the resultant moulding (and also the quantity of plastics material) and the application of an outward pressure on the plastics material urging it towards the mould surfaces until such time that the surrounding wall of plastics material is selfsupporting. The result is a moulding with an improved surface finish.
In some circumstances it may be desired to give the moulding local support or strengthening, for example, to reduce the apparent spongy feel of the moulding which may occur or to prevent any unacceptable sinking of the plastics material after the moulding is removed from the mould.
An object of the invention is to provide such local support or strengthening by an addition to the moulding process before opening the mould.
According to the invention there is provided a process of producing an injection moulding comprising introducing plastics material into a mould space, characterised by, before opening the mould, the steps of applying at at least one selected position an external pressure on one surface of the plastics material which moves the plastics material at that position inwardly of the moulding away from the adjacent mould surface, and maintaining the external pressure until the plastics material is self-supporting.
Preferably the external pressure applied at the or each selected position is sufficient to maintain the opposite surface of the plastics material against the mould surface.
In one embodiment the external pressure is applied by the introduction of a fluid between the plastics material and the mould surface at the or each selected position. Alternatively the external pressure is applied mechanically on said one surface of the plastics material at the or each selected position.
The moulding to be produced may have an internal cavity or porous core formed by the injection of a fluid within the plastics material simultaneously to the introduction of the plastics material, the external pressure being applied in the vicinity of the internal cavity or porous core.
In a case in which the moulding to be produced has an internal cavity, the external pressure may be applied against one wall of the cavity to an extent that it moves that wall into contact with the opposite wall of the plastics material and fuses therewith.
The invention also provides an apparatus for producing an injection moulding of plastics material comprising means for introducing plastics material into a mould space, characterised by means for applying at at least one selected position an external pressure on one surface of the plastics material which moves the plastics material at that position inwardly of the moulding away from the adjacent mould surface and for maintaining the external pressure until the plastics material is self-supporting.
In one embodiment the means for applying the external pressure is means for allowing a fluid under pressure to enter between the surface of the plastics material and the adjacent mould surface. Said means may be a valve member in the mould surface, and means for lifting the valve member off its seating, the fluid entering the mould space around the valve member.
In another embodiment the means for applying the external pressure may be a member in the mould surface and means, e.g. a ram, for moving the member into the mould space to apply a local mechanical pressure on the plastics material.
If desired the valve member or the pressure applying member may be an ejector pin of the mould.
The invention further provides an injection moulding of plastics material having at at least one position a local permanent deflection of one surface of the plastics material towards the opposite surface, the deflection being formed within the mould prior to the plastics material becoming self-supporting.
The moulding may also have an internal cavity or porous core. In one case the moulding has an internal cavity, and at the or each position the deflection has caused parts of the opposite walls of the moulding cavity to contact internally and become fused together. Preferably the moulding is formed by a process or apparatus as defined above.
By way of example, specific embodiments in accordance with the invention will be described with reference to the accompanying diagrammatic drawings in which:~ Figure 1 is a vertical section through a mould and a screw ram of an injection moulding press having a poppet valve member which allows fluid pressure to effect local support or strengthening of the resultant moulding; Figure 2 shows the poppet valve member in its operative position; Figures 3 and 4 are similar views to Figures 1 and 2 of a mould and a screw ram of another press which effects the local support or strengthening by mechanical pressure; Figures 5 and 6 show an arrangement suitable for applying an external pressure mechanically to a solid part of a moulding to counteract shrinkage and to form a downwardly open depression or cavity therein; and Figure 7 is a similar view to Figure 4 concerning the local support or strengthening of a moulding having a porous core instead of an internal cavity.
Regarding Figures 1 and 2, a mould 9, for use in an injection moulding press has mould parts 10, 11 defining a mould space 12. The mould parts are mounted between a fixed platen 13 and a platen 14 movable by a hydraulic ram 8 in the normal manner, and conventional ejector pins 15 are provided to assist the release of the moulding 16 when the mould is opened. Our other British Patent Application filed today describes the general method of producing the moulding which involves introducing thermoplastics material 20 from a known screw ram 17 through a sprue 18, and simultaneously injecting a fluid, preferably nitrogen, under pressure through a passageway 19 into the plastics material as the plastics material flows through the mould space between the mould surfaces.The fluid thereby forms a channel or channels or other mass 21, as desired, within the plastics material which reduces the weight of the resultant moulding and assists it to pick-up a greater surface definition from the mould surfaces by applying an outward pressure on the plastics material urging it towards the mould surfaces.
As in the case of our other patent application, this pressure is maintained until the surrounding plastics material is self-supporting and is then relieved before the mould is opened. The result is a moulding with an internal cavity or cavities.
However, in the case of the present invention there is a need to reduce the spongy feel of the moulding and to give local support or strengthening to the upper wall 22 of the moulding which carries the external surface which is visible when the moulding is used. To achieve this object it is desired to raise the lower wall 23 of the moulding at a desired position into internal contact with the upper wall and to fuse the walls together, prior to the pressure in the mass 21 being relieved. In this embodiment, the lower wall 23 is lifted locally by fluid pressure 32 (Figure 2).
A poppet valve member 24 is provided in the lower mould part 11, the valve member being held in its withdrawn, closed position by a spring 25. The conical head 26 of the valve member is open to a passageway 27 connected to a nitrogen supply 28 via a solenoid operated valve 29 and a pressure reducing valve 30. There is also a return connection via a solenoid operated valve 31 to waste.
In operation, the mould space 12 is filled with the plastics material 20 and the mass 21 of fluid, the pressure of the mass of fluid being maintained to exert an outward pressure urging the surrounding plastics material towards the mould surfaces (Figure 1). Valve 29 is then opened allowing nitrogen from the supply 28 at the pressure setting of the pressure reducing valve 30 (which setting is higher than the pressure in the mass 21) to enter the mould and the passageway 27 and to engage the conical head 26 of the poppet valve member 24. The valve member is thereby lifted against the spring pressure 25 and nitrogen passes between the lower wall 23 of the plastics material and the adjacent mould surface and lifts the lower wall into contact with the upper wall 22 (Figure 2). The contacting surfaces fuse together and some of the previous fluid filled cavity is eliminated.
When the plastics material has cooled sufficiently to become self-supporting, valve 29 is closed and valve 31 is opened to vent the nitrogen pressure 32 in the mould space 12 beneath the lower wall of the plastics material to atmosphere. At the same time, or shortly afterwards, the pressure in the mass 21 is relieved and the moulding process is completed in the manner described in our other patent application.
Figures 3 and 4 relate to an embodiment which is similar to the embodiment of Figures 1 and 2, except that the lower wall 23 of the plastics material is lifted into contact with the upper wall 22 by mechanical instead of fluid pressure. The mechanical pressure is effected by a member 40 mounted in the lower mould part 11 and attached to the piston of a hydraulic ram 41. The control means for the ram comprises a solenoid operated two-directional valve 42, and a hydraulic pump 43 driven by an electric motor 44 and protected by a relief valve 45.
As before, when the mould cavity is full, the valve 42 is energised to allow the pump to expand the ram 41 and cause the member 40 to lift the lower wall 23 of the plastics material and to maintain its raised position until the two walls fuse together (Figure 4) and the moulding is selfsupporting. The valve 42 is then reversed to return the member 40 to its inoperative position.
A limit switch (not shown) then signals that the moulding cycle may be completed.
It will be appreciated that, if desired, more than one poppet valve member 24 or lower wall lifting member 40 may be provided in different selected positions.
It is also possible that the valve member 24 or lifting member 40 may comprise one of the ejector pins 15 instead of a separate member.
In each embodiment described above, the lifting of the lower wall of the plastics material has the effect of locally closing the resultant cavity and giving support or strength to the upper wall of the moulding at that selected position.
Thus the invention can also be used to counteract any subsequent sinking of the upper wall of the plastics material which might otherwise occur after the moulding is removed from the mould, e.g. in the production of a moulding having the cavity in a strengthening rib or a boss.
In another embodiment (Figures 5 and 6) the moulding may have a part 60, e.g. a boss or rib, which is solid instead of having upper and lower walls spaced by a cavity. In this case, in accordance with the invention, an upward pressure may be applied to the lower surface of the part 60 by a rod 61 mounted for reciprocal movement in a sleeve 62 in the lower mould part 11 by a ram (not shown) in a manner similar to the embodiment of Figures 3 and 4. The external pressure applied is sufficient to counteract any sinking in the upper surface of the moulding which might otherwise occur in the vicinity of the part 60 due to shrinkage. At the same time the rod 61 is also used (see Figure 6) to form a downwardly open depression or cavity 63 in the boss 60 which has the peripheral configuration of the end of the rod, e.g. a hexagonal socket for a captive nut.As before, the applied pressure is maintained until the plastics material is selfsupporting.
The application of an external pressure, whether by a fluid as in the case of Figure 1 and 2 or mechanically as in the case of Figures 3 and 4 or Figures 5 and 6, may further be used to locally strengthen the moulding or counteract any tendency of the plastics material to sink, in the case of the moulding having a porous core instead of an internal cavity. The production of such a moulding is also described in our other patent application filed today, the porous core being formed by the injection of a liquid blowing agent instead of nitrogen. When the mould space is filled, the application of an external pressure as described above prior to the plastics material becoming self-supporting will act to locally increase the density of the plastics material.The effect is shown in Figure 7 in which the porous core 50 is compressed mechanically by the lifting member 40 between the non-porous skins 51, 52 of the plastics material. Alternatively, fluid pressure may be employed as in the case of the embodiment of Figures 1 and 2.
The resultant depression at the or each position at which the external pressure is applied need not be significant to the appearance of the moulding if the depression is on the surface of the moulding or in a position which is not visible in use. Alternatively, as in the case of the embodiment of Figures 5 and 6, a depression may be formed which has a secondary purpose during the use of the moulding.
It will be appreciated that the or each depression achieved by the application of an external pressure during the moulding cycle, as explained above, may be an isolated depression in one surface of the moulding, or one of a desired pattern of spaced depressions, or one of a plurality of depressions at specific points.

Claims (20)

1. A process of producing an injection moulding comprising introducing plastics material into a mould space, characterised by, before opening the mould, the steps of applying at at least one selected position an external pressure on one surface of the plastics material which moves the plastics material at that position inwardly of the moulding away from the adjacent mould surface, and maintaining the external pressure until the plastics material is selfsupporting.
2. A process as claimed in Claim 1, wherein the external pressure applied at the or each selected position is sufficient to maintain the opposite surface of the plastics material against the mould surface.
3. A process as claimed in Claim 1 or Claim 2, wherein the external pressure is applied by the introduction of a fluid between the plastics material and the mould surface at the or each selected position.
4. A process as claimed in Claim 1 or Claim 2, wherein the external pressure is applied mechanically on said one surface of the plastics material at the or each selected position.
5. A process as claimed in any one of the preceding claims, wherein the moulding to be produced has an internal cavity or porous core formed by the injection of a fluid within the plastics material simultaneously to the introduction of the plastics material, and wherein the external pressure is applied in the vicinity of the internal cavity or porous core.
6. A process as claimed in any one of the preceding claims, wherein the moulding to be produced has an internal cavity and the external pressure is applied against one wall of the cavity to an extent that it moves that wall into contact with the opposite wall of the plastics material and fuses therewith.
7. Apparatus for producing an injection moulding of plastics material comprising means for introducing plastics material into a mould space, characterised by means for applying at at least one selected position an external pressure on one surface of the plastics material which moves the plastics material at that position inwardly of the moulding away from the adjacent mould surface and for maintaining the external pressure until the plastics material is selfsupporting.
8. Apparatus as claimed in Claim 7, wherein the means for applying the external pressure is means for allowing a fluid under pressure to enter between the surface of the plastics material and the adjacent mould surface.
9. Apparatus as claimed in Claim 8, wherein said means is a valve member in the mould surface, and means for lifting the valve member off its seating, the fluid entering the mould space around the valve member.
10. Apparatus as claimed in Claim 9, wherein the valve member is a poppet valve member which allows the fluid to be inserted into the mould space around the valve head, to lift the valve member off its seating.
11. Apparatus as claimed in Claim 7, wherein the means for applying the external pressure is a member in the mould surface and means for moving the member into the mould space to apply a local mechanical pressure on the plastics material.
12. Apparatus as claimed in Claim 11, wherein the means for moving the member is a ram.
13. Apparatus as claimed in Claim 9 or Claim 11, wherein the valve member or the pressure applying member is an ejector pin of the mould.
14. An injection moulding of plastics material having at at least one position a local permanent deflection of one surface of the plastics material towards the opposite surface, the deflection being formed within the mould prior to the plastics material becoming self-supporting.
15. A moulding as claimed in Claim 14, wherein the moulding also has an internal cavity or porous core.
16. A moulding as claimed in Claim 15, wherein the moulding has an internal cavity, and at the or each position the deflection has caused parts of the opposite walls of the moulding cavity to contact internally and become fused together.
17. An injection moulding as claimed in Claim 12 or any one of Claims 14 to 16, formed by a process as claimed in any one of Claims 1 to 6 or apparatus as claimed in any one of Claims 7 to 13.
18. A process of producing an injection moulding substantially as hereinbefore described.
19. Apparatus for producing an injection moulding substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
20. An injection moulding of plastics material produced by a process or apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.
GB08312934A 1983-05-11 1983-05-11 Injection moulding Withdrawn GB2139549A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08312934A GB2139549A (en) 1983-05-11 1983-05-11 Injection moulding

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08312934A GB2139549A (en) 1983-05-11 1983-05-11 Injection moulding

Publications (2)

Publication Number Publication Date
GB8312934D0 GB8312934D0 (en) 1983-06-15
GB2139549A true GB2139549A (en) 1984-11-14

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Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2191442A (en) * 1986-06-14 1987-12-16 Dornier Gmbh Lindauer Producing thermoplastic parts having a structure on their surface
EP0289230A2 (en) * 1987-04-28 1988-11-02 Cinpres Limited Method of injection moulding and mouldings produced thereby
EP0309182A2 (en) * 1987-09-21 1989-03-29 Melea Limited Method, system and device utilized therein for injection molding and plastic article produced thereby
EP0309257A2 (en) * 1987-09-25 1989-03-29 Cinpres Limited Method and apparatus for injection moulding
EP0400135A1 (en) * 1988-12-05 1990-12-05 Robert E Carroll Injection mold method and apparatus.
EP0408359A1 (en) * 1989-07-12 1991-01-16 Jonathan Christopher Mott Shoe soles
GB2241663A (en) * 1990-03-06 1991-09-11 Takata Corp Moulding a vehicle air bag cover, incorporating a tear line groove for air bag release
US5204050A (en) * 1991-10-09 1993-04-20 Loren Norman S Gas assisted injection molding
WO1993014918A1 (en) * 1992-02-01 1993-08-05 Haywood Holdings Limited Gas-assisted injection moulding method and apparatus
US5273707A (en) * 1988-12-05 1993-12-28 Icp Systems, Inc. Method of injection molding
US5439365A (en) * 1992-03-23 1995-08-08 Icp Systems, Inc. Apparatus for fluid compression of injection molded plastic material
US5458846A (en) * 1988-12-05 1995-10-17 Carroll; Robert E. Method of injection molding
US5716560A (en) * 1995-09-14 1998-02-10 Icp Systems, Inc. Gas assisted injection molding combining internal and external gas pressures
US6071463A (en) * 1991-07-03 2000-06-06 Kontor Moulding Systems Limited Method and apparatus for preventing sink marks in the injection moulding of thermoplastic polymers
US6403014B1 (en) 1992-03-23 2002-06-11 Incoe Corporation Method for fluid compression of injection molded plastic material
CN104203531A (en) * 2012-04-06 2014-12-10 旭硝子株式会社 Planar body provided with resin frame and method for producing planar body provided with resin frame

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB539299A (en) * 1939-01-21 1941-09-04 Multiprises Inc Process for making articles from plastic materials by moulding under pressure
GB1176813A (en) * 1967-07-26 1970-01-07 Rolinx Ltd Hinged Articles.
GB1314452A (en) * 1970-05-06 1973-04-26 Ici Ltd Injection moulding

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB539299A (en) * 1939-01-21 1941-09-04 Multiprises Inc Process for making articles from plastic materials by moulding under pressure
GB1176813A (en) * 1967-07-26 1970-01-07 Rolinx Ltd Hinged Articles.
GB1314452A (en) * 1970-05-06 1973-04-26 Ici Ltd Injection moulding

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2191442A (en) * 1986-06-14 1987-12-16 Dornier Gmbh Lindauer Producing thermoplastic parts having a structure on their surface
EP0289230A2 (en) * 1987-04-28 1988-11-02 Cinpres Limited Method of injection moulding and mouldings produced thereby
EP0289230A3 (en) * 1987-04-28 1989-10-18 Cinpres Limited Method of injection moulding and mouldings produced thereby
US4923666A (en) * 1987-04-28 1990-05-08 Cinpres Limited Method of injection moulding
EP0309182A2 (en) * 1987-09-21 1989-03-29 Melea Limited Method, system and device utilized therein for injection molding and plastic article produced thereby
EP0309182A3 (en) * 1987-09-21 1989-10-18 Melea Ltd Method, system and device utilized therein for injection molding and plastic article produced thereby
EP0309257A2 (en) * 1987-09-25 1989-03-29 Cinpres Limited Method and apparatus for injection moulding
EP0309257A3 (en) * 1987-09-25 1989-10-18 Cinpres Limited Method and apparatus for injection moulding
US4923667A (en) * 1987-09-25 1990-05-08 Cinpres Limited Method and apparatus for injection moulding
US5643527A (en) * 1988-12-05 1997-07-01 Icp Systems, Inc. Method of injection molding
US5273707A (en) * 1988-12-05 1993-12-28 Icp Systems, Inc. Method of injection molding
EP0400135A1 (en) * 1988-12-05 1990-12-05 Robert E Carroll Injection mold method and apparatus.
US5458846A (en) * 1988-12-05 1995-10-17 Carroll; Robert E. Method of injection molding
EP0400135A4 (en) * 1988-12-05 1992-03-25 Robert E. Carroll Injection mold method and apparatus
EP0408359A1 (en) * 1989-07-12 1991-01-16 Jonathan Christopher Mott Shoe soles
US5149479A (en) * 1990-03-06 1992-09-22 Takata Corporation Method of manufacturing modular cover of air bag
GB2241663B (en) * 1990-03-06 1993-09-22 Takata Corp Method of manufacturing modular cover of air bag
FR2659267A1 (en) * 1990-03-06 1991-09-13 Takata Corp METHOD FOR MANUFACTURING A MODULAR COVER FOR INFLATABLE BALLOON FOR PROTECTION AGAINST COLLISIONS.
GB2241663A (en) * 1990-03-06 1991-09-11 Takata Corp Moulding a vehicle air bag cover, incorporating a tear line groove for air bag release
US6071463A (en) * 1991-07-03 2000-06-06 Kontor Moulding Systems Limited Method and apparatus for preventing sink marks in the injection moulding of thermoplastic polymers
US5204050A (en) * 1991-10-09 1993-04-20 Loren Norman S Gas assisted injection molding
WO1993014918A1 (en) * 1992-02-01 1993-08-05 Haywood Holdings Limited Gas-assisted injection moulding method and apparatus
US5439365A (en) * 1992-03-23 1995-08-08 Icp Systems, Inc. Apparatus for fluid compression of injection molded plastic material
US6403014B1 (en) 1992-03-23 2002-06-11 Incoe Corporation Method for fluid compression of injection molded plastic material
US5716560A (en) * 1995-09-14 1998-02-10 Icp Systems, Inc. Gas assisted injection molding combining internal and external gas pressures
CN104203531A (en) * 2012-04-06 2014-12-10 旭硝子株式会社 Planar body provided with resin frame and method for producing planar body provided with resin frame
EP2835244A4 (en) * 2012-04-06 2015-08-05 Asahi Glass Co Ltd Planar body provided with resin frame and method for producing planar body provided with resin frame
CN104203531B (en) * 2012-04-06 2017-03-08 旭硝子株式会社 The manufacture method of the plate body of the plate body of resin framework and resin framework

Also Published As

Publication number Publication date
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