US4851280A
Expired / Lapsed
US
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Composite tooling for composites manufacture
Assignee: Fiberite Inc
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Filing: 1988-04-01
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Granted: 1989-07-25
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Expires: 2008-04-01
Abstract
Abstract Composite tooling of carbon fiber reinforced polyimide of high Tg is prepared by first curing in an autoclave followed by post-curing in an air circulating oven.
Inventors
- 👤 Dipak Gupta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:23
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/02; B32B5/12; B29; B29C; B29C35/00; B29C35/02; B29C35/0227; B29C35/0233; B29C70/00; B29C70/04; B29C70/28; B29C70/30; B29C70/34; B29C70/342; B32B5/22; B32B5/24; B32B5/26; C; C08; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/243; B29K; B29K2079/00; B29K2079/08; B29K2307/00; B32B2260/00; B32B2260/02; B32B2260/021; B32B2260/04; B32B2260/046; B32B2262/00; B32B2262/10; B32B2262/106; B32B2305/00; B32B2305/07; B32B2305/076; B32B2305/08; B32B2305/72; B32B2605/00; B32B2605/18; C08J2379/00; C08J2379/04; C08J2379/08; Y; Y10; Y10S; Y10S264/00; Y10S264/78; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/30; Y10T428/31504; Y10T428/31721; Y10T442/00; Y10T442/30; Y10T442/3854; Y10T442/3902
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
170 words
A method for preparing a composite tool suitable for fabricating composite articles of high Tg comprising forming a lay-up of prepregs containing carbon fiber reinforcement and substantially stoichiometric quantities of a mixture of diamines consisting essentially of about 95% p-phenylene diamine with the remainder m-phenylene diamine and 2,3-bis-(3',4'-dicarboxyphenyl)hexafluoropropanol in an amount sufficient to produce 35 to 45 volume % of polyimide in the prepreg upon curing, enclosing the lay-up in a vacuum bag, heating the lay-up to a temperature in the range of about 650° to 730° F. while pulling a vacuum on the contents of the bag and while applying a pressure on the bag at least 180 pounds per square inch to cure the assembly until the Tg of the composite tool is between 650° and 700° F., releasing the pressure and vacuum and post curing the assembly to increase Tg by heating in a recirculating air oven to a temperature of at least 700°-725° F. until the Tg of the composite tool reaches at least 730° F.
Claim 2
Independent Claim
170 words
A method for preparing a composite tool suitable for fabricating composite articles of high Tg comprising forming a lay-up of prepregs containing carbon fiber reinforcement and substantially stoichiometric quantities of a mixture of diamines consisting essentially of about 95% p-phenylene diamine with the remainder m-phenylene diamine and 2,3-bis-(3',4'-dicarboxyphenyl)hexafluoropropanol in an amount sufficient to produce 35 to 45 volume % of polyimide in the prepreg upon curing, enclosing the lay-up in a vacuum bag, heating the lay-up to a temperature in the range of about 650° to 730° F. while pulling a vacuum on the contents of the bag and while applying a pressure on the bag at least 180 pounds per square inch to cure the assembly until the Tg of the composite tool is between 650° and 700° F., releasing the pressure and vacuum and post curing the assembly to increase Tg by heating in a recirculating air oven to a temperature of at least 700°-725° F. until the Tg of the composite tool reaches at least 730° F.
Claim 3
Dependent Claim
74 words
A composite tool for manufacture of fiber reinforced high temperature composite parts comprising from 35 to 45 volume % of a polyimide consisting essentially of the following recurring structural units: ##STR2## wherein A is present in an amount of about 95% an d B the remainder, and from 55 to 65 volume % of carbon fiber reinforcement, said tool having a porosity of less than 6% and a Tg of at least 730° F.
Claim 4
Dependent Claim
74 words
A composite tool for manufacture of fiber reinforced high temperature composite parts comprising from 35 to 45 volume % of a polyimide consisting essentially of the following recurring structural units: ##STR2## wherein A is present in an amount of about 95% an d B the remainder, and from 55 to 65 volume % of carbon fiber reinforcement, said tool having a porosity of less than 6% and a Tg of at least 730° F.
Claim 5
Dependent Claim
48 words
A composite tool in accordance with claim 2 which has a surface layer of the same polyimide reinforced with a 24×24 yarns/inch fabric of about 1000 filament carbon fiber, and wherein the proportion of fiber to matrix is substantially the same as in the body of the tool.
Claim 6
Dependent Claim
33 words
A composite tool in accordance with claim 2 which has a surface layer of a polyimide film of between 0.2 and 0.75 mils thick, said polyimide being formed from oxydianiline and pyromellitic dianhydride.
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) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |