US3615979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of making sheet molding compound and materials thereof
Assignee: Owens Corning
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Filing: 1968-07-01
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Granted: 1971-10-26
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Expires: 1988-07-01
Abstract
Abstract The specification describes a process for making a sheet molding compound wherein a layer of resin-filler paste that includes a thickening agent and a hardening catalyst is put down upon a first layer of sheet material; a layer of glass fibers that are sized with a material which induces wet out is placed thereon; following which another layer of the resin-filler paste containing the catalyst is placed thereon and covered by a second layer of sheet material. The sandwich thus formed is fed into the bite of rollers which squeeze out air and compress the resinfiller paste around the sized fibers, following which the composite is placed under further compaction that includes a perforating means which forces needlelike members through at least one layer of the sheet material, through the resin-filled paste, and into the layer of fibers for the removal of remaining entrapped air. The glass fibers which are used are sized with a material that includes both a hardening resin, and a nonhardening resin. Specifically, the fibers are coated with an unsaturated polyester resin and a saturated polyester resin which are preferably deposited on the glass fibers as emulsified particles.
Inventors
- 👤 Carlton J Davis Sr
- 👤 Richard P Wood
- 👤 Everett R Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:57
CPC Classifications
B; B29; B29C; B29C37/00; B29C37/006; B29C37/0064; B29B; B29B15/00; B29B15/08; B29B15/10; B29B15/12; B29B15/122; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/50; B29C70/504; B29C70/508; B29C70/54; B29C70/542; B32; B32B; B32B27/00; C; C03; C03C; C03C25/00; C03C25/10; C03C25/24; C03C25/26; C03C25/32; C03C25/323
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
48 words
The method of claim 1 wherein molten streams of glass are attenuated to a diameter less than approximately 0.0005, and the glass fibers are immediately coated and protected with an emulsion consisting essentially of the unsaturated polyester resin, organic coupling agent, and saturated polyester resin of claim 1.
Claim 2
Dependent Claim
35 words
The method of claim 2 wherein the fibers are chopped into less than approximately 2 inch lengths which are then applied in a layer over the top of the first described layer of molding compound.
Claim 3
Dependent Claim
34 words
The method of claim 1 followed by the steps of: stripping the sheet material from the composite, and molding the composite under heat and pressure to react the unsaturated bonds and cross-link the resin.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the coating material for the fibers comprises the following approximate weight percentages: 8.4 unsaturated polyester resin, 0.5 gamma methacryloxypropyltrimethoxy silane, and 0.7 saturated polyester resin.
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein the saturated polyester resin is formed by reacting approximately 1 mol phthalic anhydride, 1 mol of succinic anhydride, and 2.3 mols of propylene glycol to an acid number of 30- 35.
Claim 6
Dependent Claim
43 words
The method of claim 1 wherein the molding compound comprises the following materials in approximate percentages by weight: 42.7 unsaturated resin, 0.85 dicumyl peroxide, 0.09 2,5-dimethyl hexyl-2,5-di (peroxybenzoate), 1.7 zinc stearate, 6.4 polyethylene homopolymer, 43.7 CaCo3 filler, 4.27 styrene, and 1.28 hydrated CaO.
Claim 7
Dependent Claim
57 words
The method of claim 1 wherein the resin-filler paste consists essentially of an unsaturated polyester resin made by reacting approximately 1 mol of phthalic anhydride, approximately 1 mol of maleic anhydride, and approximately 2 mols of propylene glycol to an acid number of 30 to 35 and the filler is a mixture of CaCO3 and polyethylene homopolymer.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein the sheet materials are polyethylene films.
Claim 9
Dependent Claim
24 words
The method of claim 9 wherein the composite is passed beneath a roller that is provided with sharp projections which puncture the polyethylene film.
Claim 10
Independent Claim
172 words
A method of producing moldable glass fiber reinforced resin strip material comprising: coating glass fibers with a resin forming material which contains a glass coupling agent and is capable of mixing with a later applied resin containing material, said resin having molecules with a first type of functionality at the ends thereof for producing thermoplastic linear chains and a second type of functionality intermediate the ends for cross-linking the molecules, applying lengths of the coating glass fibers above described onto the layer of resin containing paste, applying additional resin containing paste over the layer of fibers, placing another layer of sheet material over the layer of additional resin containing paste, compressing the composite thus formed together, puncturing at least one layer of sheet material at closely spaced intervals generally coterminous with said layer of fibers and subjecting the composite to pressure to remove entrapped air, and linking ends of the resin molecules together by the first type of functionality to thicken the resin into a thermoplastic condition without appreciably cross-linking the molecules.
Claim 11
Dependent Claim
37 words
The process of claim 11 wherein the solids of the coating on the glass fibers comprises more than approximately 5 percent of a saturated resin and is devoid of a catalyst which produces cross-linking of the resin.
Claim 12
Independent Claim
163 words
The method of producing glass fiber reinforced molding compound comprising: applying a polymerizable resin containing paste onto a sheet material, said polymerizable resin having molecules with a first type of functionality at the ends thereof for producing thermoplastic linear chains and a second type of functionality intermediate the ends for cross-linking the molecules, applying lengths of glass fibers onto the layer of paste, applying additional polymerizable resin containing paste over the layer of fibers, placing another layer of sheet material over the layer of additional paste, compressing the composite thus formed together, puncturing at least one layer of sheet material at closely spaced intervals generally coterminous with said layer of fibers by projections which penetrate into the layer of fibers, subjecting the composite to a kneading action to remove entrapped air out of the punctures, and linking the ends of the resin molecules together by the first type of functionality to thicken the resin to a thermoplastic condition without appreciably cross-linking the molecules.
Claim 13
Dependent Claim
37 words
The method of claim 13 wherein the step of subjecting the composite to pressure to remove entrapped air involves the kneading of the molding compound laterally of the sheet to displace air through the punctured sheet material.
Claim 14
Dependent Claim
23 words
The method of claim 14 wherein the kneading step is performed by a series of rolls having spaced apart annular ridges and valleys.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-25 | 1975-04-26 | 1975-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-25 | 1979-04-26 | 1979-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-25 | 1983-04-26 | 1983-10-26 | $7700.00 | Window Closed / Lapsed |