US3965229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a foam fibrillated fibrous web from an isotactic polypropylene and polyethylene blend
Assignee: Sun Ventures Inc
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Filing: 1973-12-14
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Granted: 1976-06-22
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Expires: 1993-12-14
Abstract
Abstract Non-woven fabrics are produced from oriented foam fibrillated webs containing 75 to 98 wt. % polypropylene and 2 to 25 wt. % polyethylene. The webs are assembled in a plurality of layers and then bonded by heat and pressure either with or without the presence of an adhesive.
Inventors
- 👤 Gary L. Driscoll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:20
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/42; D01D5/423; D04; D04H; D04H13/00; Y; Y10; Y10S; Y10S264/00; Y10S264/08; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24074; Y10T428/31504; Y10T428/31855; Y10T428/31938
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
209 words
A process of producing a foam fibrillated fibrous web comprising heating a blend of from 75 to 98 weight percent as based on said blend of isotactic polypropylene and from 25 to 2 weight percent as based on said blend of polyethylene in an extruder to a temperature generally maintained in a range of from 175° to 236°C whereby a molten blend is formed, extruding said blend and from 0.1 to 20 percent by weight as based on said blend of a material which is gaseous under the extrusion conditions used mixed with said molten blend from a die which is generally maintained in the temperature range of from 200° to 235°C into a zone of reduced pressure to produce a foam fibrillated fibrous web extrudate, quenching said extrudate to a temperature below about 150°C while withdrawing said extrudate from said die by a first linear take up means at a linear rate of from 2 to 25 times the linear rate at which said blend reaches the lips of said die whereby a foam fibrillated web is formed, and stretching said foam fibrillated web from 2 to 10 times in the machine direction at a temperature of from about 90°C to about 150°C to increase the strength thereof.
Claim 2
Dependent Claim
209 words
A process of producing a foam fibrillated fibrous web comprising heating a blend of from 75 to 98 weight percent as based on said blend of isotactic polypropylene and from 25 to 2 weight percent as based on said blend of polyethylene in an extruder to a temperature generally maintained in a range of from 175° to 236°C whereby a molten blend is formed, extruding said blend and from 0.1 to 20 percent by weight as based on said blend of a material which is gaseous under the extrusion conditions used mixed with said molten blend from a die which is generally maintained in the temperature range of from 200° to 235°C into a zone of reduced pressure to produce a foam fibrillated fibrous web extrudate, quenching said extrudate to a temperature below about 150°C while withdrawing said extrudate from said die by a first linear take up means at a linear rate of from 2 to 25 times the linear rate at which said blend reaches the lips of said die whereby a foam fibrillated web is formed, and stretching said foam fibrillated web from 2 to 10 times in the machine direction at a temperature of from about 90°C to about 150°C to increase the strength thereof.
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) | 1979-06-22 | 1979-12-22 | 1980-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-22 | 1983-12-22 | 1984-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-22 | 1987-12-22 | 1988-06-22 | $7700.00 | Window Closed / Lapsed |