Patent US3243719A successfully refreshed from Google Patents.
Patent US3898113A successfully refreshed from Google Patents.
US3898113A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a continuous strand sheet molding compound
Assignee: Aerojet Rocketdyne Holdings Inc
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Filing: 1974-08-08
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Granted: 1975-08-05
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Expires: 1994-08-08
Abstract
Abstract An improved sheet molding compound is provided having a greatly increased tensile strength in the direction of its longitudinal axis. The tensile strength increase results from the inclusion of a number of continuous glass fiber rovings. There is also disclosed a method for making the sheet molding compound and incorporating the continuous rovings between the top and bottom layers of resinous material. As part of the process, an improved doctor blade is provided which has a plurality of holes through which the continuous rovings are pulled after passing through a bath of the resinous material, thus causing the roving to be thoroughly impregnated with the resin.
Inventors
- 👤 Raymond W Meyer
- 👤 Francis R Mcgranaghan
- 👤 Dale K Evans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:01
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/50; B29C70/504; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/1062; Y10T428/00; Y10T428/249921; Y10T428/249924; Y10T428/24994; Y10T428/249942
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
25 words
THE AXES OF SAID FIBROUS ROVINGS BEING SELECTIVELY SPACED TRANSVERSELY APART THROUGH SELECTED HORIZONTALLY SPACED OPENINGS DEFINED BY A GUIDE BAR ACROSS SAID CARRIER SHEETS,
Claim 2
Dependent Claim
25 words
THE AXES OF SAID FIBROUS ROVINGS BEING SELECTIVELY SPACED TRANSVERSELY APART THROUGH SELECTED HORIZONTALLY SPACED OPENINGS DEFINED BY A GUIDE BAR ACROSS SAID CARRIER SHEETS,
Claim 3
Independent Claim
84 words
THE METHOD OF CONTINUOUSLY MAKING A FIBER REINFORCED SHEET MOLDING COMPOUND HAVING SUPERIOR MOLDING QUALITIES WHEN PRESS-FORMED IN A MATCHED-METAL MOLD COMPRISING THE STEPS OF: A. SPREADING A TOP LAYER OF RESINOUS MATERIAL UNDER A CONVENTIONAL DOCTOR BLADE ON ONE SIDE OF A MOVING FLEXIBLE TOP CARRIER SHEET, B. SPREADING A BOTTOM LAYER OF RESINOUS MATERIAL UNDER AN IMPROVED DOCTOR BLADE ON ONE SIDE OF A MOVING FLEXIBLE BOTTOM CARRIER SHEET, C. PASSING A PLURALITY OF FIBROUS ROVINGS THROUGH A MASS OF RESINOUS MATERIAL,
Claim 4
Independent Claim
84 words
THE METHOD OF CONTINUOUSLY MAKING A FIBER REINFORCED SHEET MOLDING COMPOUND HAVING SUPERIOR MOLDING QUALITIES WHEN PRESS-FORMED IN A MATCHED-METAL MOLD COMPRISING THE STEPS OF: A. SPREADING A TOP LAYER OF RESINOUS MATERIAL UNDER A CONVENTIONAL DOCTOR BLADE ON ONE SIDE OF A MOVING FLEXIBLE TOP CARRIER SHEET, B. SPREADING A BOTTOM LAYER OF RESINOUS MATERIAL UNDER AN IMPROVED DOCTOR BLADE ON ONE SIDE OF A MOVING FLEXIBLE BOTTOM CARRIER SHEET, C. PASSING A PLURALITY OF FIBROUS ROVINGS THROUGH A MASS OF RESINOUS MATERIAL,
Claim 5
Dependent Claim
13 words
EACH OF SAID FIBROUS ROVINGS COMPRISING A LOOSE BUNDLE OF INDIVIDUAL FIBERS, AND
Claim 6
Dependent Claim
13 words
EACH OF SAID FIBROUS ROVINGS COMPRISING A LOOSE BUNDLE OF INDIVIDUAL FIBERS, AND
Claim 7
Dependent Claim
70 words
The additional steps following step d) of claim 1 including i. cutting into short strands a diverted portion of said fibrous rovings passing from said improved doctor blade; and ii. randomly dropping said short strands of said fibrous rovings as impregnated onto said bottom layer of resinous material as spread on said bottom carrier sheet to thereby include said short strands with said fibrous rovings as disposed by step e).
Claim 8
Dependent Claim
13 words
each of said fibrous rovings comprising a loose bundle of individual fibers, and
Claim 9
Dependent Claim
13 words
each of said fibrous rovings comprising a loose bundle of individual fibers, and
Claim 10
Dependent Claim
139 words
each of said fibers being individually coated with said resinous material within said mass of resinous material, d. respectively compressing together each said bundle of said fibrous rovings passing from said bath through selected horizontally spaced and sized orifices defined through said improved doctor blade to remove excess resinous material and to uniformly impregnate each of said compressed rovings with said resinous material, e. passing said fibrous rovings from said orifices as horizontally spaced onto said bottom layer of resinous material as spread on said bottom carrier sheet, f. compressing said top carrier sheet toward said bottom carrier sheet to force said top layer of resinous material and said bottom layer of resinous material together to consolidate said top layer of resinous material, said fibrous rovings and said bottom layer of resinous material into a composite sheet molding compound.
Claim 11
Dependent Claim
139 words
each of said fibers being individually coated with said resinous material within said mass of resinous material, d. respectively compressing together each said bundle of said fibrous rovings passing from said bath through selected horizontally spaced and sized orifices defined through said improved doctor blade to remove excess resinous material and to uniformly impregnate each of said compressed rovings with said resinous material, e. passing said fibrous rovings from said orifices as horizontally spaced onto said bottom layer of resinous material as spread on said bottom carrier sheet, f. compressing said top carrier sheet toward said bottom carrier sheet to force said top layer of resinous material and said bottom layer of resinous material together to consolidate said top layer of resinous material, said fibrous rovings and said bottom layer of resinous material into a composite sheet molding compound.
Claim 12
Dependent Claim
11 words
The method of claim 1 wherein said fibers comprise glass fibers.
Claim 13
Dependent Claim
23 words
EACH OF FIBERS BEING INDIVIDUALLY COATED WITH SAID RESINOUS MATERIAL WITHIN SAID MASS OF RESINOUS MATERIAL, D. RESPECTIVELY COMPRESSING TOGETHER EACH SAID BUNDLE
Claim 14
Dependent Claim
23 words
EACH OF FIBERS BEING INDIVIDUALLY COATED WITH SAID RESINOUS MATERIAL WITHIN SAID MASS OF RESINOUS MATERIAL, D. RESPECTIVELY COMPRESSING TOGETHER EACH SAID BUNDLE
Claim 15
Dependent Claim
24 words
The method of claim 2 wherein said fibrous rovings comprise from about 10 p.b.w. to about 30 p.b.w. of said short strands of fiber.
Claim 16
Dependent Claim
14 words
The method of claim 1 wherein said resinous material includes a metal oxide thickener.
Claim 17
Dependent Claim
19 words
The method of claim 2 wherein said short strands of fiber are less than about 2 inches in length.
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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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |