US4680150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing foamed plastics
Assignee: Inoac Corp
•
Filing: 1985-07-30
•
Granted: 1987-07-14
•
Expires: 2005-07-30
Abstract
Abstract A method for manufacturing a predetermined shape of molded plastics, comprising the steps of introducing a foamable shell forming material in molding dies, introducing a hard core forming material having a foaming agent on the shell forming material, clamping the molding dies together, and heating both the material located in the molding dies by an induction heating.
Inventors
- 👤 Hiromichi Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:48
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/02; B29C44/04; B29C33/00; B29C33/02; B29C33/06; B29K; B29K2105/00; B29K2105/25; B29K2105/253; B29L; B29L2031/00; B29L2031/30; B29L2031/3005
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
182 words
A method for manufacturing molded plastics having a predetermined shape by heating a plastic raw material which is located in molding dies having electrodes by applying high frequency voltage to the electrodes to melt and plasticize the plastic raw material, so that a foaming agent contained in the plastic material dissolves, wherein said method comprises; introducing a flowable shell forming material in the molding dies and introducing a core forming material having a foaming agent mixed therein in or on the shell forming material so that the core forming material is upstanding in the molding dies, said core forming material having a hardness which is sufficient to maintain its original shape when it is located in or on the shell forming material; clamping the molding dies together; and initially heating the shell forming material and subsequently the core forming material by the application of high frequency voltage thereto until the core forming material foams, enlarges in size and forces the shell forming material to flow in the mold cavity and surround the foamed core to form a molded composite foamed resin article.
Claim 2
Independent Claim
182 words
A method for manufacturing molded plastics having a predetermined shape by heating a plastic raw material which is located in molding dies having electrodes by applying high frequency voltage to the electrodes to melt and plasticize the plastic raw material, so that a foaming agent contained in the plastic material dissolves, wherein said method comprises; introducing a flowable shell forming material in the molding dies and introducing a core forming material having a foaming agent mixed therein in or on the shell forming material so that the core forming material is upstanding in the molding dies, said core forming material having a hardness which is sufficient to maintain its original shape when it is located in or on the shell forming material; clamping the molding dies together; and initially heating the shell forming material and subsequently the core forming material by the application of high frequency voltage thereto until the core forming material foams, enlarges in size and forces the shell forming material to flow in the mold cavity and surround the foamed core to form a molded composite foamed resin article.
Claim 3
Dependent Claim
17 words
A method according to claim 1, wherein said shell forming material has a viscosity below 100,000 centipoise.
Claim 4
Dependent Claim
16 words
A method according to claim 1, wherein said shell forming material is made of polyvinylchloride paste.
Claim 5
Dependent Claim
17 words
A method according to claim 1, wherein said shell forming material has a foaming agent mixed therein.
Claim 6
Dependent Claim
22 words
A method according to claim 1, wherein said core forming material is a highly viscous sol having a viscosity above 100,000 centipoise.
Claim 7
Dependent Claim
21 words
A method according to claim 1, wherein said core forming material is a solid which is premolded into a predetermined shape.
Claim 8
Dependent Claim
18 words
A method according to claim 1, wherein said core forming material has a base resin consisting of polyvinylchloride.
Claim 9
Dependent Claim
51 words
A method according to claim 1, wherein said core forming material is located in the shell forming material so as to project upward form the latter, so that the upper surface of the core forming material is located close to the upper surface of a cavity defined in the molding dies.
Claim 10
Independent Claim
22 words
A method according to any one of the preceding claims, wherein said molded plastics are decorative and protective moldings for an automobile.
References Cited (Backward Citations)
US2247337A
Cited
US2753642A
Cited
US2743931A
Cited
US3478134A
Cited
US3248461A
Cited
US3345439A
Cited
US3420923A
Cited
US3379799A
Cited
US3354243A
Cited
US3444275A
Cited
US3816574A
Cited
US3937774A
Cited
US4110139A
Cited
US4124670A
Cited
US4129634A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |