Patent EP0321117A2 successfully refreshed from Google Patents.
EP0321117A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and system for localized fluid-assisted injection molding and body formed thereby
Assignee: Melea Ltd
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Filing: 1988-11-28
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Granted: —
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Expires: 2008-11-28
Abstract
Abstract A method and system are disclosed for locally introducing fluid, such as a gas, at a predetermined location into molten resin downstream from a resin injection aperture to form a hollow part. The gas is utilized at the localized area to distribute the molten resin, to eliminated molded in stress and to prevent formation of sink marks in the part during resin solidification. An overflow reservoir (112) outside of the mold cavity (114) is filled with the resin during resin injection and then the gas is introduced into the reservoir (112) through a fluid aperture (116, 118) and into the part. The reservoir creates a cocoon of solidified material to act as a seal to prevent gas leakage. One hollow body formed by the method and system includes a substantially endless hollow body portion with a fluid opening for communicating the interior of the hollow body portion with the locally introduced fluid. The hollow body provides an internal gas manifold and means for greater structural integrity.
Inventors
- 👤 Norman S. Loren
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 07:33
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/1703; B29C45/1704
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
154 words
A method for making a hollow-shaped body from a plastic resin in a fluid-assisted injection molding system including a mold having an injection aperture, a body forming cavity and a resin reservoir in communication with the cavity, the method comprising: injecting an amount of molten resin sufficient for the preparation of the body from an injection nozzle through the injection aperture, along a resin flow path and into the cavity in the mold, wherein the resin at least partially fills the reservoir; injecting fluid into the molten resin in the reservoir through at least one fluid aperture in the reservoir to at least partially distribute the resin over interior surfaces defining the cavity whereby the body is formed within a predetermined portion of the cavity; cooling the body so formed to a temperature beneath the softening point of the resin; relieving the pressure within the body; and opening the mold to remove the body.
Claim 2
Independent Claim
154 words
A method for making a hollow-shaped body from a plastic resin in a fluid-assisted injection molding system including a mold having an injection aperture, a body forming cavity and a resin reservoir in communication with the cavity, the method comprising: injecting an amount of molten resin sufficient for the preparation of the body from an injection nozzle through the injection aperture, along a resin flow path and into the cavity in the mold, wherein the resin at least partially fills the reservoir; injecting fluid into the molten resin in the reservoir through at least one fluid aperture in the reservoir to at least partially distribute the resin over interior surfaces defining the cavity whereby the body is formed within a predetermined portion of the cavity; cooling the body so formed to a temperature beneath the softening point of the resin; relieving the pressure within the body; and opening the mold to remove the body.
Claim 3
Dependent Claim
131 words
In an injection molding system for making a hollow-shaped body from a plastic resin, the system including a mold, a source of fluid and an injection molding machine having a nozzle for injecting an amount of molten resin sufficient for the preparation of the body into the mold through an injection aperture along a resin flow path and into a cavity in the mold, fluid injecting means for locally injecting fluid into the molten resin through at least one fluid aperture remote from the injection aperture to at least partially distribute the resin over the interior surfaces defining the cavity, the improvement comprising: the mold having a resin reservoir in communication with the cavity to receive the plastic resin and wherein the reservoir communicates the fluid aperture and the mold cavity.
Claim 4
Dependent Claim
131 words
In an injection molding system for making a hollow-shaped body from a plastic resin, the system including a mold, a source of fluid and an injection molding machine having a nozzle for injecting an amount of molten resin sufficient for the preparation of the body into the mold through an injection aperture along a resin flow path and into a cavity in the mold, fluid injecting means for locally injecting fluid into the molten resin through at least one fluid aperture remote from the injection aperture to at least partially distribute the resin over the interior surfaces defining the cavity, the improvement comprising: the mold having a resin reservoir in communication with the cavity to receive the plastic resin and wherein the reservoir communicates the fluid aperture and the mold cavity.
Claim 5
Dependent Claim
19 words
The invention as claimed in claim 1 or claim 2 wherein the mold has more than one injection aperture.
Claim 6
Dependent Claim
19 words
The invention as claimed in claim 1 or claim 2 wherein the mold has more than one resin reservoir.
Claim 7
Dependent Claim
16 words
The invention as claimed in claim 1 or claim 2 including more than one fluid aperture.
Claim 8
Dependent Claim
27 words
The invention as claimed in claim 2 wherein the fluid injecting means includes a valve mechanism for controlling the flow of the fluid into the resin reservoir.
Claim 9
Dependent Claim
17 words
The invention as claimed in claim 2 wherein the system includes a multi-nozzle, hot runner, manifold system.
Claim 10
Dependent Claim
15 words
The invention as claimed in claim 2 wherein the system includes a multi-gate runner system.
Claim 11
Dependent Claim
43 words
The invention as claimed in claim 1 or claim 2 wherein the mold has a resin spillover reservoir in communication with the cavity and wherein excess resin at least partially fills the spillover reservoir during distribution of the resin over the interior surfaces.
Claim 12
Dependent Claim
17 words
The invention as claimed in claim 9 wherein the mold has more than one resin spillover reservoir.
Claim 13
Dependent Claim
24 words
The invention as claimed in claim 1 or claim 2 wherein the mold includes a pin for at least partially forming the fluid aperture.
Claim 14
Dependent Claim
16 words
The invention as claimed in claim 11 wherein the pin has a thermally conductive tip portion.
Claim 15
Dependent Claim
72 words
In a plastic hollow body formed by a fluid-assisted injection molding system including a mold having a body forming cavity and an injection aperture wherein plastic resin is injected through the injection aperture and wherein fluid is injected into the resin through a separate fluid aperture in the mold to at least partially distribute the resin, the improvement comprising: a substantially endless hollow body portion formed within the body by the fluid.
Claim 16
Dependent Claim
72 words
In a plastic hollow body formed by a fluid-assisted injection molding system including a mold having a body forming cavity and an injection aperture wherein plastic resin is injected through the injection aperture and wherein fluid is injected into the resin through a separate fluid aperture in the mold to at least partially distribute the resin, the improvement comprising: a substantially endless hollow body portion formed within the body by the fluid.
Claim 17
Dependent Claim
42 words
The body as claimed in claim 13 wherein the fluid aperture is formed in the body portion, the fluid aperture including two orifices extending in substantially opposite directions to distribute the resin in substantially opposite directions to form the hollow body portion.
Claim 18
Dependent Claim
23 words
The body as claimed in claim 13 or claim 14 wherein the endless body portion is formed about the periphery of the part.
Claim 19
Dependent Claim
17 words
The body as claimed in claim 13 wherein said hollow body portion includes first and second compartments.
Claim 20
Dependent Claim
24 words
The body as claimed in claim 13 wherein a resin reservoir is formed within the hollow body portion by the resin during injection thereof.
Claim 21
Dependent Claim
30 words
The body as claimed in claim 13 or claim 14 or claim 17 wherein the mold has a resin spillover reservoir located substantially opposite the fluid aperture outside the body.
Claim 22
Dependent Claim
16 words
The body as claimed in claim 14 wherein the fluid aperture is formed by a pin.
Claim 23
Dependent Claim
16 words
The body as claimed in claim 19 wherein the pin has a thermally conductive tip portion.
References Cited (Backward Citations)
No citation records indexed.
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