US4933229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High wet-strength polyolefin blown microfiber web
Assignee: 3M Co
•
Filing: 1989-04-21
•
Granted: 1990-06-12
•
Expires: 2009-04-21
Abstract
Abstract A polyolefin BMF web made from a mixture of polypropylene and surfactant can have high wet strength when (a) the surfactant is nonionic and (b) the surfactant is mixed with the polypropylene at a static mixer that interconnects the extruder and the BMF die. By so postponing the addition of the surfactant, it is protected from both the exceedingly high temperatures of the extruder and from the high shearing forces within the extruder. The surfactant also is heated to high temperatures for a much shorter time than if it were premixed with the polypropylene.
Inventors
- 👤 Thomas I. Insley
- 👤 Daniel E. Meyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:51
CPC Classifications
D; D01; D01F; D01F1/00; D01F1/02; B; B29; B29B; B29B7/00; B29B7/30; B29B7/32; B29B7/325; B29B7/34; B29B7/38; B29B7/46; B29B7/48; B29B7/74; B29B7/7461; B29B7/80; B29B7/88; B29B7/94; B29C; B29C48/00; B29C48/022; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/36; B29C48/362; B29C48/78; B29C48/80; B29C48/83; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; B29C48/92; D01D; D01D1/00; D01D1/06; D01D1/065; D01F6/00; D01F6/02; D01F6/04; D01F6/06; Y; Y10; Y10S; Y10S428/00; Y10S428/903; Y10T; Y10T442/00; Y10T442/60; Y10T442/608; Y10T442/614; Y10T442/615; Y10T442/626
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
43 words
Blown microfiber (BMF) web, the microfibers of which comprise an extruded polypropylene with a blended in nonionic surfactant, which surfactant is blended in so as to provide a BMF web having a "Web Wet Strength" at least 130% of its "Web Dry Strength".
Claim 2
Dependent Claim
43 words
Blown microfiber (BMF) web, the microfibers of which comprise an extruded polypropylene with a blended in nonionic surfactant, which surfactant is blended in so as to provide a BMF web having a "Web Wet Strength" at least 130% of its "Web Dry Strength".
Claim 3
Dependent Claim
17 words
Blown microfiber web as defined in claim 1 wherein the fiber-forming constituent consists essentially of only polypropylene.
Claim 4
Dependent Claim
25 words
Blown microfiber web as defined in claim 2 wherein the surfactant is present in an amount of at least 6% by weight of the polypropylene.
References Cited (Backward Citations)
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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) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |