Nonwoven elastic fibrous webs and methods for making them
US7744807B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2006 |
| Grant date | Jun 29, 2010 |
| Priority date | — |
| Expiry date | Jan 7, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/697
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A coherent nonwoven fibrous web comprises directly formed elastic fibers that have a molecular orientation sufficient to provide a birefringence number of at least 1×10−5 and preferably at least 1×10−2. The web can be made by a method that comprises a) extruding filaments of elastic-fiber-forming material; b) directing the filaments through a processing chamber in which gaseous currents apply a longitudinal stress to the filaments that attenuates and draws the filaments; c) maintaining the filaments at their orienting temperature while the filaments are under attenuating and drawing stress for a sufficient time for molecules within the filaments to become oriented along the length of the filaments; d) cooling the filaments to their orientation-locking temperature while the filaments are under attenuating and drawing stress and further cooling the filaments to a solidified fiber form; and e) collecting the solidified fibers as a fibrous nonwoven web. In a preferred aspect, the method includes the further step of annealing the collected fibers by exposing them to a temperature that is above their shrinking temperature but less than their relaxation temperature, and preferably bonding…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.