US3937860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtration material
Assignee: JP Stevens and Co Inc
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Filing: 1975-04-23
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Granted: 1976-02-10
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Expires: 1995-04-23
Abstract
Abstract A high temperature resistant filtration material is produced having outer layers of a nonwoven fabric made of fibers of an aromatic polyamide having repeating units of the formula ##SPC1## A first inner layer of nonwoven fabric made of glass fibers and a second inner layer woven from yarns of glass or said aromatic polyamide. The fibers of the layers are interentangled by needling to form an integral structure.
Inventors
- 👤 Irwin J. Gusman
- 👤 Carlo Strack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:10
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/22; B32B5/24; B32B5/26; B01; B01D; B01D39/00; B01D39/14; B32B5/02; B32B5/06; D; D04; D04H; D04H1/00; D04H1/40; D04H1/42; D04H1/4209; D04H1/4218; D04H1/4326; D04H1/4334; D04H1/4342; D04H1/4374; B32B2250/00; B32B2250/20; B32B2262/00; B32B2262/02; B32B2262/0261; B32B2262/0269; B32B2262/10; B32B2262/101; B32B2307/00; B32B2307/30; B32B2307/306; Y; Y10; Y10T; Y10T442/00; Y10T442/30; Y10T442/3707; Y10T442/3724; Y10T442/3732; Y10T442/374
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
65 words
A high temperature resistant filtration material comprising: a. Two outer layers of nonwoven fabric of fibers of an aromatic polyamide having repeating units of the formula ##SPC3## b. A first inner layer of nonwoven fabric of glass fibers, and c. A second inner layer of woven fabric made of yarns of glass or said aromatic polyamide, said layers being needled together into an integral structure.
Claim 2
Dependent Claim
65 words
A high temperature resistant filtration material comprising: a. Two outer layers of nonwoven fabric of fibers of an aromatic polyamide having repeating units of the formula ##SPC3## b. A first inner layer of nonwoven fabric of glass fibers, and c. A second inner layer of woven fabric made of yarns of glass or said aromatic polyamide, said layers being needled together into an integral structure.
Claim 3
Dependent Claim
25 words
A filtration material as claimed in claim 1 wherein said fibers of an aromatic polyamide of said outer layer have a maximum denier of 5.
Claim 4
Dependent Claim
24 words
A filtration material as claimed in claim 1 wherein the glass fibers of said first inner layer have a maximum denier of about 5.
Claim 5
Dependent Claim
106 words
A high temperature resistant filtration material comprising: a. Two outer layers of nonwoven fabric of fibers which have a maximum denier of about 5 and are composed of an aromatic polyamide having repeating units of the formula ##SPC4## b. A first inner layer of nonwoven fabric of glass fibers having a maximum denier of about 5, said layer having a weight of about 1 to 10 ozs./yd. 2 c. A second inner layer of woven fabric made of yarns of glass or said aromatic polyamide, said fabric having a weight of about 0.75 to 10 ozs./yd. 2 said layers being needled together into an integral structure.
Claim 6
Dependent Claim
106 words
A high temperature resistant filtration material comprising: a. Two outer layers of nonwoven fabric of fibers which have a maximum denier of about 5 and are composed of an aromatic polyamide having repeating units of the formula ##SPC4## b. A first inner layer of nonwoven fabric of glass fibers having a maximum denier of about 5, said layer having a weight of about 1 to 10 ozs./yd. 2 c. A second inner layer of woven fabric made of yarns of glass or said aromatic polyamide, said fabric having a weight of about 0.75 to 10 ozs./yd. 2 said layers being needled together into an integral structure.
Claim 7
Dependent Claim
20 words
A filtration material as claimed in claim 4 wherein said woven fabric is made of yarn containing continuous glass filaments.
Claim 8
Dependent Claim
23 words
A filtration material as claimed in claim 4 wherein said woven fabric is made of spun yarn containing fibers of said aromatic polyamide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-09 | 1979-08-11 | 1980-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-09 | 1983-08-11 | 1984-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-09 | 1987-08-11 | 1988-02-10 | $7700.00 | Window Closed / Lapsed |