Patent US5106568A successfully refreshed from Google Patents.
US5106568A
Expired / Lapsed
US
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Method and apparatus for vacuum bag molding of composite materials
Assignee: McDonnell Douglas Corp
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Filing: 1991-11-15
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Granted: 1992-04-21
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Expires: 2011-11-15
Abstract
Abstract A method and apparatus for vacuum bag molding of composite materials which eliminates the need for a porous release sheet. Prepregs are placed on a forming tool and overlayed with at least one sheet of nonporous material and a breather sheet and then enclosed within an impermeable membrane. The volume enclosed by the membrane is evacuated, the resin in the prepregs is outgassed, and the prepregs are coalesced to mold the prepregs to the shape of the forming tool. After curing the resin, the temperature is reduced and the resultant article is removed from the forming tool.
Inventors
- 👤 Paul J. Honka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:08
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/30; B29C70/34; B29C70/342; B29C70/40; B29C70/42; B29C70/44; B29C43/00; B29C43/02; B29C43/10; B29C43/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
100 words
A method of vacuum molding composite materials, comprising the steps of: (a) laying up, on a forming tool, a plurality of prepregs, each comprising uncured resin-impregnated filaments; (b) overlaying said plurality of prepregs with at least one sheet of a nonporous material; (c) overlaying said nonporous material with a breather material; (d) enclosing said prepregs, said nonporous material, and said breather material within an impermeable membrane; (e) evacuating the volume enclosed by said impermeable membrane; (f) outgassing said resin in said prepregs; (g) coalescing said prepregs; (h) curing said resin; and (i) removing said composite material from said forming tool.
Claim 2
Independent Claim
100 words
A method of vacuum molding composite materials, comprising the steps of: (a) laying up, on a forming tool, a plurality of prepregs, each comprising uncured resin-impregnated filaments; (b) overlaying said plurality of prepregs with at least one sheet of a nonporous material; (c) overlaying said nonporous material with a breather material; (d) enclosing said prepregs, said nonporous material, and said breather material within an impermeable membrane; (e) evacuating the volume enclosed by said impermeable membrane; (f) outgassing said resin in said prepregs; (g) coalescing said prepregs; (h) curing said resin; and (i) removing said composite material from said forming tool.
Claim 3
Dependent Claim
29 words
The method of vacuum molding composite materials as recited in claim 1, further comprising the step of sealing said impermeable membrane to the outer edges of said forming tool.
Claim 4
Independent Claim
95 words
An apparatus for vacuum molding composite materials, comprising: (a) a forming tool; (b) a plurality of prepregs, each comprising uncured resin-impregnated filaments, which are layed-up on said forming tool; (c) a nonporous release sheet overlayed onto said plurality of prepregs; (d) a breather material overlayed onto said non-porous release sheet; (e) an impermeable membrane for enclosing said plurality of prepregs, said non-porous release sheet, and said breather sheet; (f) means for evacuating the volume enclosed by said impermeable membrane; (g) means for outgassing said resin in said prepregs; and (h) means for coalescing said prepregs.
Claim 5
Independent Claim
95 words
An apparatus for vacuum molding composite materials, comprising: (a) a forming tool; (b) a plurality of prepregs, each comprising uncured resin-impregnated filaments, which are layed-up on said forming tool; (c) a nonporous release sheet overlayed onto said plurality of prepregs; (d) a breather material overlayed onto said non-porous release sheet; (e) an impermeable membrane for enclosing said plurality of prepregs, said non-porous release sheet, and said breather sheet; (f) means for evacuating the volume enclosed by said impermeable membrane; (g) means for outgassing said resin in said prepregs; and (h) means for coalescing said prepregs.
Claim 6
Dependent Claim
28 words
The apparatus for vacuum molding composite materials as recited in claim 3, further comprising a nonporous release sheet sandwiched between said forming tool and said plurality of prepregs.
Claim 7
Dependent Claim
23 words
The apparatus for vacuum molding composite materials as recited in claim 3, wherein said outgassing means and said coalescing means is an autoclave.
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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) | 1995-04-21 | 1995-10-21 | 1996-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-21 | 1999-10-21 | 2000-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-21 | 2003-10-21 | 2004-04-21 | $7700.00 | Window Closed / Lapsed |