Nonwoven web with improved barrier properties
US5213881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Nov 26, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/68
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
There is disclosed a nonwoven web for use as a barrier layer in an SMS fabric laminate. The web is formed at commercially acceptable polymer melt throughputs (greater than 3 PIH) by using a reactor granule polyolefin, preferably polypropylene, that has been modified by the addition of peroxide in amounts ranging from up to 3000 ppm to reduce the molecular weight distribution from an initial molecular weight distribution of from 4.0 to 4.5 Mw/Mn to a range of from 2.2 to 3.5 Mw/Mn. Also the addition of peroxide increases the melt flow rate (lowers viscosity) to a range between 800 up to 5000 gms/10 min at 230.degree. C. The resulting web has an average fiber size of from 1 to 3 microns and pore sizes distributed predominantly in the range from 7 to 12 microns, with a lesser amount of pores from 12 to 25 microns, with virtually no pores greater than 25 microns, and with the peak of the pore size distribution less than 10 microns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.