US4758395A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding thick parts of fibrous-ply-reinforced resin
Assignee: PMC Inc
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Filing: 1986-11-04
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Granted: 1988-07-19
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Expires: 2006-11-04
Abstract
Abstract The method comprises placing upper and lower stacks of unimpregnated fibrous reinforcement plies having a core of preimpregnated fibrous reinforcement plies therebetween in a mold and injecting chemically activated resin to impregnate the upper and lower stacks of unimpregnated fibrous reinforcement plies and initiate curing of heat-activatable resin of the core, and removing the molded part from the mold after curing and cooling of the part.
Inventors
- 👤 Earl M. Zion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:18
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/08; B29C70/28; B29C70/40; B29C70/42; B29C70/46; B29C70/48
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
150 words
A method of molding thick parts of fibrous-ply-reinforced thermosetting resin, the method comprising placing in a lower portion of a mold upper and lower stacks of unimpregnated fibrous reinforcement plies having a core of preimpregnated fibrous reinforcement plies therebetween said upper stack, said lower stack and said core having a thickness up to two inches, the plies of the core being preimpregnated with a thickened thermosetting resin, heat-activable at about 150° F., closing the mold with an upper portion thereof, and injecting chemically activated thermosetting resin into the mold under pressure, to impregnate the upper and lower stacks of unimpregnated fibrous reinforcement plies, said chemically activated thermosetting resin giving off heat during cure, and preventing excessive heat loss from the chemically activated thermosetting resin to the mold by insulating said mold, whereby heat given off by the chemically activated thermosetting resin initiates curing of the thermosetting resin of the core.
Claim 2
Independent Claim
150 words
A method of molding thick parts of fibrous-ply-reinforced thermosetting resin, the method comprising placing in a lower portion of a mold upper and lower stacks of unimpregnated fibrous reinforcement plies having a core of preimpregnated fibrous reinforcement plies therebetween said upper stack, said lower stack and said core having a thickness up to two inches, the plies of the core being preimpregnated with a thickened thermosetting resin, heat-activable at about 150° F., closing the mold with an upper portion thereof, and injecting chemically activated thermosetting resin into the mold under pressure, to impregnate the upper and lower stacks of unimpregnated fibrous reinforcement plies, said chemically activated thermosetting resin giving off heat during cure, and preventing excessive heat loss from the chemically activated thermosetting resin to the mold by insulating said mold, whereby heat given off by the chemically activated thermosetting resin initiates curing of the thermosetting resin of the core.
Claim 3
Dependent Claim
15 words
A method as claimed in claim 1 wherein the reinforcement plies are glass fiber plies.
Claim 4
Dependent Claim
16 words
A method as claimed in claim 1 wherein the reinforcement plies include woven glass roving plies.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1 wherein the reinforcement plies of the core are woven glass roving plies.
Claim 6
Dependent Claim
31 words
A method as claimed in claim 1 wherein the upper stack of reinforcement plies comprises a plurality of woven glass roving plies interleaved between a plurality of continuous glass strand plies.
Claim 7
Dependent Claim
31 words
A method as claimed in claim 1 wherein the lower stack of reinforcement plies comprises a plurality of woven glass roving plies interleaved between a plurality of continuous glass strand plies.
Claim 8
Dependent Claim
46 words
A method as claimed in claim 1 wherein each of the upper and lower stacks of reinforcement plies comprises a plurality of woven glass roving plies interleaved between a plurality of continuous glass strand plies and the plies of the core are woven glass roving plies.
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) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |