Process of making polypropylene fibers
US6878327B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2002 |
| Grant date | Apr 12, 2005 |
| Priority date | — |
| Expiry date | Jan 8, 2023 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F6/06
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for the production of polypropylene fibers from a propylene polymer including isotactic polypropylene produced by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The polymer is heated to a molten state and extruded to form a fiber preform at a temperature within the range of about 170°-210° C. The fiber preform is spun at a spinning speed of at least 200 meters per minute and quenched at a heat transfer rate of no more than 12 joules per second fiber. The spun fiber is then subjected to a winding operation. The fiber may be drawn subsequent to the quenching operation and prior to winding. The cooled fiber preform may be drawn to produce a fiber at a draw ratio within the range of about 1.5-4.0 with shrinkage of the fiber over the range of the draw ratio at a variance of ±25% of the median of the shrinkage factor over the draw ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.