Non-woven fiber sheet and process and apparatus for its production
US5051159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 19, 1990 |
| Grant date | Sep 24, 1991 |
| Priority date | — |
| Expiry date | Jul 19, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2239/1291
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process apparatus for producing a non-woven, especially a non-woven electret, fiber sheet provides for directing the non-woven fibers at a collecting surface and into an electric field between at least one electrode and the collecting surface. This process, in which the fibers are collected in the electric field, enables the economical production of a non-woven electret fiber sheet of single layer structure having large amount of polarized charges (giving a total electric charge per unit area of at least 7.times.10.sup.-11 Coulomb/cm.sup.2), and a weight of at least 60 g/m.sup.2, preferably greater than 80 g/cm.sup.2. The non-woven electret sheet may have the large amount of electret charge throughout its thickness and/or a uniform weight distribution and thus have excellent dust collecting properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.