Patent US4863665A successfully refreshed from Google Patents.
US4863665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tri-injection of hollow articles
Assignee: Husky Injection Molding Systems Ltd
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Filing: 1988-02-08
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Granted: 1989-09-05
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Expires: 2008-02-08
Abstract
Abstract Method for tri-injecting a plurality of thermoplastic materials to mold an article having a layered wall structure using thermoplastic materials having different optimum processing temperatures including the maintenance of the optimum temperatures in flow paths individual to each material from its source at least to the injection nozzle. At least two of the nozzle channels are insulated to prevent heat transfer and to maintain the temperature of the thermoplastic materials.
Inventors
- 👤 Robert D. Schad
- 👤 Paul P. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:49
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/16; B29C45/1603; B29C45/1607; B29C2045/1609; B29C45/1642; B29C2045/1656; B29C45/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
159 words
A method of molding layers of at least three different thermoplastic materials sequentially comprising the steps of: providing individual sources of said different materials each properly and individually conditioned for processing, providing a mold cavity, providing a nozzle for introducing said different thermoplastic materials into said mold cavity, introducing said different thermoplastic materials into said mold cavity through a hot runner system including individual conduits leading from each source to the nozzle and from the nozzle to the mold cavity through separate nozzle channels, maintaining at least two of said materials at the appropriate process temperature from its source through the hot runner system and through the separate nozzle channels to the mold cavity, and insulating at least two of the said nozzle channels from each other substantially coextensive therewith to block heat transfer from one nozzle channel to the other and maintain two of said materials at said different processing temperatures prior to entry into said mold cavity.
Claim 2
Independent Claim
159 words
A method of molding layers of at least three different thermoplastic materials sequentially comprising the steps of: providing individual sources of said different materials each properly and individually conditioned for processing, providing a mold cavity, providing a nozzle for introducing said different thermoplastic materials into said mold cavity, introducing said different thermoplastic materials into said mold cavity through a hot runner system including individual conduits leading from each source to the nozzle and from the nozzle to the mold cavity through separate nozzle channels, maintaining at least two of said materials at the appropriate process temperature from its source through the hot runner system and through the separate nozzle channels to the mold cavity, and insulating at least two of the said nozzle channels from each other substantially coextensive therewith to block heat transfer from one nozzle channel to the other and maintain two of said materials at said different processing temperatures prior to entry into said mold cavity.
Claim 3
Dependent Claim
26 words
The method of claim 1 plus the step of providing valve means in at least one of said hot runner systems for blocking the conduit therein.
Claim 4
Dependent Claim
19 words
The method of claim 2 plus the step of disposing a charging ram in circuit with said blocked conduit.
Claim 5
Dependent Claim
21 words
The method of claim 3 plus the step of locating the charging ram between the valve means and the mold cavity.
Claim 6
Dependent Claim
22 words
The method of claim 4 plus the step of locating at least one charging ram between the valve means and the nozzle.
Claim 7
Dependent Claim
70 words
The method of claim 1 including the step of providing a plurality of mold cavities, providing a hot runner system including individual conduits leading from each source to each mold cavity, and maintaining at least two of said materials at the appropriate process temperature from its source to the mold cavity, and maintaining at least one of said materials at the appropriate process temperatures from its source to the nozzle.
Claim 8
Dependent Claim
31 words
The method of claim 6 plus the step of introducing said different thermoplastic materials into each said mold cavity by means of a nozzle in circuit with said hot runner system.
Claim 9
Dependent Claim
29 words
The method of claim 7 plus the step of providing a plurality of nozzles in circuit with said hot runner system, one nozzle being individual to each mold cavity.
Claim 10
Dependent Claim
31 words
The method of claim 1 including a step of separately heating the individual conduits leading from the sources to the nozzle to maintain said different materials at their appropriate process temperature.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |