Patent US4891176A successfully refreshed from Google Patents.
US4891176A
Expired / Lapsed
US
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Resin transfer molding process
Assignee: AUTO-FAB Inc A CORP OF MI
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Filing: 1988-05-31
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Granted: 1990-01-02
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Expires: 2008-05-31
Abstract
Abstract A method for manufacturing a panel, such as an automotive panel, using the resin transfer molding (RTM) process. The method includes the steps of preforming a first mat of glass fibers into a shape approximating one side of the panel and, similarly, preforming a second mat of glass fibers into a shape approximating a second side of the panel. A urethane core is sandwiched in between the preformed mats to thereby form a premolded assembly. This premolded assembly is placed into a mold and a settable resin is injected into the mold to form the panel.
Inventors
- 👤 James P. Drysdale
- 👤 L. David Landrith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:42
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/68; B29C70/86; B29C70/865; B29C70/04; B29C70/28; B29C70/40; B29C70/42; B29C70/46; B29C70/48; B29C2791/00; B29C2791/001
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
A method for manufacturing a panel comprising the steps of: preforming a first mat of glass fibers into a shape approximating one side of the panel, preforming a second mat of glass fibers into a shape approximating a second side of the panel, sandwiching a core in between said preformed mats to thereby form a premolded assembly, placing said premolded assembly in a mold, injecting a settable resin into said mold, and placing a flexible sheet between the core and one of said mats prior to forming the premolded assembly wherein said sheet minimizes shrinkage lines on said panel.
Claim 2
Independent Claim
99 words
A method for manufacturing a panel comprising the steps of: preforming a first mat of glass fibers into a shape approximating one side of the panel, preforming a second mat of glass fibers into a shape approximating a second side of the panel, sandwiching a core in between said preformed mats to thereby form a premolded assembly, placing said premolded assembly in a mold, injecting a settable resin into said mold, and placing a flexible sheet between the core and one of said mats prior to forming the premolded assembly wherein said sheet minimizes shrinkage lines on said panel.
Claim 3
Dependent Claim
14 words
The method as defined in claim 1 wherein said resin is a polyester resin.
Claim 4
Dependent Claim
16 words
The method as defined in claim 1 wherein said resin is a liquid catalyzed polyester resin.
Claim 5
Dependent Claim
14 words
The method as defined in claim 1 wherein said core is constructed from urethane.
Claim 6
Dependent Claim
14 words
The method as defined in claim 1 wherein said sheet is a polyethylene sheet.
Claim 7
Dependent Claim
25 words
The method as defined in claim 1 wherein each fiberglass mat includes a bonding agent which, when set, holds the mat in its preformed shape.
Claim 8
Dependent Claim
16 words
The method as defined in claim 6 wherein said bonding agent is a thermoplastic bonding agent.
Claim 9
Dependent Claim
16 words
The method as defined in claim 6 wherein said bonding agent is a thermosetting bonding agent.
Claim 10
Dependent Claim
37 words
The method as defined in claim 6 wherein said preforming steps each comprises the following steps: placing said mat between two heated shaping tools, compressing said tools together with said mat sandwiched in between the shaping tools.
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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) | 1993-01-01 | 1993-07-03 | 1994-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-01 | 1997-07-03 | 1998-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-01 | 2001-07-03 | 2002-01-02 | $7700.00 | Window Closed / Lapsed |