US4683099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moulding of composite materials
Assignee: Rolls Royce PLC
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Filing: 1986-02-20
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Granted: 1987-07-28
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Expires: 2006-02-20
Abstract
Abstract A method of moulding composite materials in which prepregs of resin impregnated filaments are interposed between a shaped partially contained polytetrafluoroethylene body and a die. The assembly is heated to cause the polytetrafluoroethylene body to thermally expand and compress the prepregs against the die so that the prepregs are moulded to the shape of the die and the resin in the prepregs cures.
Inventors
- 👤 Frank A. Buxton
- 👤 David J. Barraclough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:54
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/30; B29C70/34; B29C70/345; B29C43/00; B29C43/02; B29C43/10; B29C43/32; B29K; B29K2105/00; B29K2105/06; B29K2105/08; B29K2827/00; B29K2827/12; B29K2827/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
127 words
A method of moulding composite materials which composite materials comprise reinforcing filaments enclosed in a resin matrix, said method comprising: interposing a plurality of prepregs comprising resin impregnated filaments between a shaped body and means corresponding in shape to said shaped body, wherein at least a major portion of said shaped body is polytetrafluoroethylene, and increasing the temperature of the resulting assembly to a temperature within the range of 290° C. and 330° C. so that the resultant thermal expansion of said shaped polytetrafluoroethylene body provides the compression of said prepregs between said shaped polytetrafluoroethylene body and said means corresponding in shape with said shaped body so that said prepregs are consolidated and moulded to a shape corresponding generally with that defined by said shaped polytetrafluoroethylene body.
Claim 2
Independent Claim
127 words
A method of moulding composite materials which composite materials comprise reinforcing filaments enclosed in a resin matrix, said method comprising: interposing a plurality of prepregs comprising resin impregnated filaments between a shaped body and means corresponding in shape to said shaped body, wherein at least a major portion of said shaped body is polytetrafluoroethylene, and increasing the temperature of the resulting assembly to a temperature within the range of 290° C. and 330° C. so that the resultant thermal expansion of said shaped polytetrafluoroethylene body provides the compression of said prepregs between said shaped polytetrafluoroethylene body and said means corresponding in shape with said shaped body so that said prepregs are consolidated and moulded to a shape corresponding generally with that defined by said shaped polytetrafluoroethylene body.
Claim 3
Dependent Claim
45 words
A method of moulding a composite material as claimed in claim 1 wherein said resin is a thermosetting resin and the maximum temperature which is reached during said method is sufficiently high and is maintained for a sufficiently long period for said resin to cure.
Claim 4
Dependent Claim
63 words
A method of moulding a composite material as claimed in claim 1 wherein at least some of said prepregs are placed in intimate contact with previously moulded composite material comprising reinforcing filaments enclosed in a resin matrix in such a manner that said prepregs are bounded by the resin therein to said previously moulded composite material during the course of said moulding process.
Claim 5
Dependent Claim
34 words
A method of moulding a composite material as claimed in claim 1 wherein said means corresponding in shape with said shaped body comprises a shaped body which is in the form of a die.
Claim 6
Dependent Claim
40 words
A method of moulding a composite material as claimed in claim 1 wherein said means corresponding in shape with said shaped body comprises a vacuum bag moulding assembly which assumes the shape of said shaped body upon the evacuation thereof.
Claim 7
Dependent Claim
52 words
A method of moulding a composite material as claimed in claim 5 wherein additional pressure is exerted upon said vacuum bag moulding assembly after the evacuation thereof to augment the resistance of said vacuum bag moulding assembly to the pressure exerted thereon resulting from the thermal expansion of said shaped polytetrafluoroethylene body.
Claim 8
Dependent Claim
21 words
A method of moulding a composite material as claimed in claim 6 wherein said additional pressure is exerted by an autoclave.
Claim 9
Dependent Claim
32 words
A method of moulding a composite material as claimed in claim 1 wherein said polytetrafluoroethylene is intimately mixed with a filler material which filler material is chemically inert with respect to polytetrafluoroethylene.
Claim 10
Dependent Claim
21 words
A method of moulding a composite material as claimed in claim 8 wherein said filler material is glass-fibre or bronze powder.
Claim 11
Dependent Claim
18 words
A method of moulding a composite material as claimed in claim 1 wherein said filaments are of carbon.
Claim 12
Dependent Claim
19 words
A method of moulding a composite material as claimed in claim 2 wherein said thermosetting resin is a polyimide.
Claim 13
Dependent Claim
67 words
A method of moulding a composite material as claimed in claim 11 wherein the temperature of said assembly is slowly raised to a temperature of 205° C., said temperature of 205° C. being maintained for two hours whereupon the temperature is slowly increased to between 290° C. and 330° C. and held at that temperature for one hour whereupon the temperature is slowly reduced to 60° C.
Claim 14
Dependent Claim
25 words
A method of moulding a composite material as claimed in claim 6 wherein the pressure exerted by said autoclave is 200 pounds per square inch.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |