Nonwoven fabric in an electret state and process for its production
US5409766A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1993 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | Oct 18, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/68
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The improved nonwoven fabric in an electret state is composed of monofilaments with an average fiber diameter of 0.5-100 .mu.m that are formed of a polymer composition containing no more than 1 mol % of polar groups; the fabric has a weight of 5-100 g/m.sup.2, a bulk density of 0.05-0.40 g/cm.sup.3 and an average surface charge density of at least 0.1.times.10.sup.-9 C/cm.sup.2. This nonwoven fabric is capable of efficient dust collection and its trapping ability is retained for a prolonged time even in a hot and humid condition. Also disclosed are a process for producing this nonwoven fabric, as well as a filtering and an air masking material which are composed of that nonwoven fabric.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.