US4891176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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
2026-10-27 19:27
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.
References Cited (Backward Citations)
US3309450A
Cited
US4131667A
Cited
US4240999A
Cited
US4405543A
Cited
US4250136A
Cited
US4405538A
Cited
US4379103A
Cited
US4420447A
Cited
US4734147A
Cited
US4556529A
Cited
US4548861A
Cited
US4560523A
Cited
US4676041A
Cited
US4714575A
Cited
US4734230A
Cited
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 |