US4189338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming autogenously bonded non-woven fabric comprising bi-component fibers
Assignee: JNC Corp
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Filing: 1975-07-29
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Granted: 1980-02-19
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Expires: 1995-07-29
Abstract
Abstract A porous non-woven fabric having a good dimensional stability and uniformity is prepared from a web obtained by arranging side-by-side composite fibers alone or a blend thereof with another fibrous material into a web and heat-treating the resulting web at a specified temperature, said composite fibers having few naturally developed crimps and being obtained by stretching unstretched side-by-side composite fibers consisting of a polypropylene component and an olefin polymer component having a specified melting point and a specified melt flow rate.
Inventors
- 👤 Shozo Ejima
- 👤 Susumu Tomioka
- 👤 Tadao Matsumoto
- 👤 Naruaki Hane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:49
CPC Classifications
D; D01; D01F; D01F8/00; D01F8/04; D01F8/06; D04; D04H; D04H1/00; D04H1/40; D04H1/54; Y; Y10; Y10S; Y10S264/00; Y10S264/26
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
A process for preparing a non-woven fabric having a porous structure which consists of (a) forming a plurality of unstretched side-by-side composite fibers consisting of a first component comprised mainly of crystalline polypropylene and a second component composed mainly of at least one olefin polymer other than crystalline polypropylene, said second component having a melting point at least 30° C. lower than that of said polypropylene, and having a melt flow rate in the range of 1.5-5 times that of said polypropylene (b) stretching said unstretched composite fibers at a stretching temperature at or above 20° C. below the melting point of said second component at a stretching ratio of 3 or more, (c) incorporating said stretched fibers having 12 crimps or less per 25 mm into a web, (d) subjecting said web to heat treatment at a temperature higher than the melting point of said second component but lower than the melting point of said polypropylene whereby said non-woven fabric is stabilized mainly by melt adhesion of said second component of said composite fibers.
Claim 2
Dependent Claim
175 words
A process for preparing a non-woven fabric having a porous structure which consists of (a) forming a plurality of unstretched side-by-side composite fibers consisting of a first component comprised mainly of crystalline polypropylene and a second component composed mainly of at least one olefin polymer other than crystalline polypropylene, said second component having a melting point at least 30° C. lower than that of said polypropylene, and having a melt flow rate in the range of 1.5-5 times that of said polypropylene (b) stretching said unstretched composite fibers at a stretching temperature at or above 20° C. below the melting point of said second component at a stretching ratio of 3 or more, (c) incorporating said stretched fibers having 12 crimps or less per 25 mm into a web, (d) subjecting said web to heat treatment at a temperature higher than the melting point of said second component but lower than the melting point of said polypropylene whereby said non-woven fabric is stabilized mainly by melt adhesion of said second component of said composite fibers.
Claim 3
Dependent Claim
27 words
A process in accordance with claim 1 wherein said web additionally includes fibers selected from the group consisting of cotton, wool, viscose, rayon, glass fibers and asbestos.
Claim 4
Dependent Claim
30 words
A process in accordance with claim 1 wherein said web additionally includes fibers selected from the group consisting of natural fibers, semisynthetic cellulose acetate fibers, synthetic fibers and inorganic fibers.
Claim 5
Dependent Claim
32 words
A process according to claim 1 wherein said olefin polymer is an atactic polypropylene having an average molecular weight of 30,000 to 90,000 and a melting point of 100° to 140° C.
Claim 6
Dependent Claim
164 words
A process for preparing a non-woven fabric having a porous structure which consists of (a) forming a plurality of unstretched side-by-side composite fibers consisting of a first component comprised mainly of crystalline polypropylene and a second component composed mainly of polyethylene, said polyethylene having a melting point at least 30° C. lower than that of said polypropylene, and having a melt flow rate in the range of 1.5-5 times that of said polypropylene, (b) stretching said unstretched composite fibers at a stretching temperature at or above 20° C. below the melting point of said polyethylene and at a stretching ratio of 3 or more, (c) forming said stretched fibers having 12 crimps or less per 25 mm into a web, (d) subjecting said web to heat treatment at a temperature higher than the melting point of said polyethylene but lower than the melting point of said polypropylene whereby said non-woven fabric is stabilized mainly by melt adhesion of the polyethylene of said composite fibers.
Claim 7
Dependent Claim
164 words
A process for preparing a non-woven fabric having a porous structure which consists of (a) forming a plurality of unstretched side-by-side composite fibers consisting of a first component comprised mainly of crystalline polypropylene and a second component composed mainly of polyethylene, said polyethylene having a melting point at least 30° C. lower than that of said polypropylene, and having a melt flow rate in the range of 1.5-5 times that of said polypropylene, (b) stretching said unstretched composite fibers at a stretching temperature at or above 20° C. below the melting point of said polyethylene and at a stretching ratio of 3 or more, (c) forming said stretched fibers having 12 crimps or less per 25 mm into a web, (d) subjecting said web to heat treatment at a temperature higher than the melting point of said polyethylene but lower than the melting point of said polypropylene whereby said non-woven fabric is stabilized mainly by melt adhesion of the polyethylene of said composite fibers.
Claim 8
Dependent Claim
27 words
A process according to claim 5 wherein said polyethylene has a melt index of 9 to 34 at 190° C. and under a load of 2,160 g.
Claim 9
Dependent Claim
32 words
A process according to claim 5 wherein said olefin polymer is an atactic polypropylene having an average molecular weight of 30,000 to 90,000 and a melting point of 100° to 140° C.
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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) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |