Patent US4921647A successfully refreshed from Google Patents.
US4921647A
Expired / Lapsed
US
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Method of shaping a laminated thermoplastic billet
Assignee: Shell USA Inc
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Filing: 1988-10-27
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Granted: 1990-05-01
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Expires: 2008-10-27
Abstract
Abstract A laminate having at least one non-dielectrically heatable first material, (processable at an optimum starting temperature), and at least one dielectrically-heatable second material, (processable at a higher optimum finish temperature), is initially brought to its starting temperature. The dielectrically heatable second material is then heated to its finish temperature, by being subjected to radio frequency (RF) or microwave radiation at selected frequency(s). The laminate is then stretched so as to shape the laminate while the first material and second material are at or near to their optimum processing temperatures.
Inventors
- 👤 David R. Stewart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:54
CPC Classifications
B; B29; B29C; B29C35/00; B29C35/02; B29C35/12; B29B; B29B11/00; B29B11/04; B29B11/14; B29B13/00; B29B13/08; B29C49/00; B29C49/071; B29C35/08; B29C35/0805; B29C2035/0855; B29C2949/00; B29C2949/07; B29C2949/0715
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
98 words
A process for forming a shaped article of manufacture from a pre-assembled laminate having a dielectrically non-heatable first material and a dielectrically-heatable second material and a dielectrically-heatable third material, said process comprising the steps of; bringing said first material, second material, and third material to a starting temperature, dielectrically heating said second material to a first finish temperature, dielectrically heating said third material to a second finish temperature higher than said first finish temperature, shaping said article of manufacture before the temperature of said second material or the temperature of said third material decreases below said starting temperature.
Claim 2
Dependent Claim
98 words
A process for forming a shaped article of manufacture from a pre-assembled laminate having a dielectrically non-heatable first material and a dielectrically-heatable second material and a dielectrically-heatable third material, said process comprising the steps of; bringing said first material, second material, and third material to a starting temperature, dielectrically heating said second material to a first finish temperature, dielectrically heating said third material to a second finish temperature higher than said first finish temperature, shaping said article of manufacture before the temperature of said second material or the temperature of said third material decreases below said starting temperature.
Claim 3
Dependent Claim
78 words
The process of claim 1 wherein the steps of; dielectrically heating said second material to a first finish temperature, and dielectrically heating said third material to a second finish temperature higher than said first finish temperature, are done by; simultaneously applying to said second material and said third material a first dielectric radiation field having a firs frequency and a first field strength, and a second dielectric radiation field having a second frequency and a second field strength.
References Cited (Backward Citations)
US3488411A
Cited
US3519514A
Cited
GB1238881A
Cited
US3846522A
Cited
US3802985A
Cited
US3787158A
Cited
US4154893A
Cited
US3947204A
Cited
US4005967A
Cited
US4304751A
Cited
US4441876A
Cited
US4451721A
Cited
US4435244A
Cited
US4420670A
Cited
US4462786A
Cited
US4448345A
Cited
US4512942A
Cited
US4778551A
Cited
US4790972A
Cited
US4810457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-30 | 1993-10-30 | 1994-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-30 | 1997-10-30 | 1998-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-30 | 2001-10-30 | 2002-05-01 | $7700.00 | Window Closed / Lapsed |