US3619339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous nonwoven film-fibril sheet and process for producing said sheet
Assignee: EIDP Inc
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Filing: 1969-07-08
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Granted: 1971-11-09
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Expires: 1989-07-08
Abstract
Abstract A nonwoven film-fibril sheet of substantially continuous plexifilamentary strands is point-bonded and perforated, within specified limits, to provide a porous, strong, nonpapery fabriclike sheet for, e.g., garment end uses.
Inventors
- 👤 William Lee Garrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:52
CPC Classifications
D; D04; D04H; D04H3/00; D04H3/08; D04H3/16; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/1056; Y10T156/1057; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24802; Y10T428/24826; Y10T428/29; Y10T428/2904; Y10T428/2907
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
13 words
Sheet of claim 1 having about 300 to 500 point-bonds per square inch.
Claim 2
Dependent Claim
18 words
Sheet of claim 1 wherein said total cross-sectional area of said perforations is at least about 6 percent.
Claim 3
Dependent Claim
18 words
Sheet of claim 1 wherein said total cross-sectional area of said perforations is less than about 10 percent.
Claim 4
Dependent Claim
13 words
Sheet of claim 1 having at least about 600 perforations per square inch.
Claim 5
Dependent Claim
14 words
Sheet of claim 1 having between about 1,500 and 2,000 perforations per square inch.
Claim 6
Dependent Claim
19 words
Sheet of claim 1 wherein said average cross-sectional area per perforation is at least about 10 5 square inch.
Claim 7
Dependent Claim
156 words
A process for preparing a porous nonwoven film-fibril sheet comprising: a. providing a film-fibril sheet of substantially continuous plexifilamentary strands, b. contacting about 200 to 800 spaced portions per square inch of at least one surface of said sheet with sufficient heat and pressure to point-bond about 7 to 13 percent of the planar area of said sheet, and c. perforating said sheet to at least about 500 perforations per square inch, each of said perforations being provided by separating film-fibril elements of said sheet less than about 0.021 inch, with the points of perforation upon said sheet being such that at least about 5 percent, but not more than about 10 percent of said sheet remains point-bonded, said perforating providing a total cross-sectional area of said perforations of at least about 3 percent of the planar area of said sheet with the average cross-sectional area per perforation being less than about 10 4 square inches.
Claim 8
Dependent Claim
12 words
Process of claim 8 wherein said perforating is done in multiple passes.
Claim 9
Dependent Claim
17 words
Process of claim 8 wherein said perforating is to less than about 2,000 perforations per square inch.
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) | 1974-11-08 | 1975-05-10 | 1975-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-08 | 1979-05-10 | 1979-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-08 | 1983-05-10 | 1983-11-09 | $7700.00 | Window Closed / Lapsed |