Viscous dispersion for forming wet-laid, non-woven fabrics
Abstract
Abstract An improved process for forming a non-woven fabric by wet-laying, on paper making equipment, staple length, synthetic fibers having a length to diameter ratio of about 400 to 3000, and an improved, non-woven fabric produced by the process. The process involves forming a stable, viscous, uniform, air-fiber-water dispersion by: adding the fibers to a high-shear agitated mixture of water and a dispersant to separate the fibers and to completely and uniformly distribute the individual fibers throughout the resulting, high-shear agitated, air, water and fiber mixture; and then, slowly adding a thixotropic thickener to the high-shear agitated mixture to form the viscous, air-fiber-water dispersion, having a nascent viscosity of about 10 to 125 cps., when measured at a shear rate of 30.5 sec.-1, and in which the individual fibers are restrained from becoming entangled and from forming knits, bundles, and strings.
Inventors
- 👤 Ralph E. Brandon
- 👤 Charles J. Davis
- 👤 Michael Ring
- 👤 Roy S. Swenson
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |