Method of producing crimped polypropylene fibers
Abstract
Abstract BULKY CRIMPED POLYPROPYLENE FIBERS, THE COIL CRIMPS OF WHICH HAVE A COIL DIAMETER OF E.G. LESS THAN 0.7 MM., AND ARE OF GOOD REPRODUCTIBILITY, ARE MADE BY COOLING OR QUENCHING POLYPROPYLENE FILAMENT, IMMEDIATELY AFTER COMING OUT OF THE SPINNING ORIFICE, ASYMMETRICALLY IN THE CROSS-SECTIONAL DIRECTION OF THE FILAMENT SO AS TO CREATE A CROSSSECTIONAL ANISOTROPY IN THE FILAMENT STRUCTURE, AND THEN STRETCHING THE FILAMENT AND HEAT TREATING THE SAME IN A RELAXED STATE. USE IS MADE OF A SPINNERETTE IN WHICH THE MINIMUM DISTANCE BETWEEN THE ORIFICES IS MORE THAN 4.0 MM. COOLING IS EFFECTED BY COOLING GAS UNDER PARTICULAR CONDITIONS OF VELOCITY AND DISTANCE BETWEEN SPINNERETTE FACE AND GAS. THE FIBER IS STRETCHED 2.5 OR MORE TIMES ITS LENGTH AT A PARTICULAR TEMPERATURE SO THAT THE FINE VOIDS ARE DISTRIBUTED ASYMMETRICALLY IN THE CROSS SECTION OF THE FIBER.
Inventors
- 👤 Tatsuki Matsuo
- 👤 Shosuke Nanri
- 👤 Ryunosuke Masuda
- 👤 Hikoyuki Uchihashi
- 👤 Katsuya Ishitobi
Bibliographic Details
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |