Selective filtration device
US5732718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1994 |
| Grant date | Mar 31, 1998 |
| Priority date | — |
| Expiry date | Aug 23, 2014 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD04H1/43835
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a filter for tobacco smoke composed of at least one layer of a wet-formed absorbent fibrous nonwoven composite structure containing: 1) from about 30 to about 65 percent, by weight, of pulp fibers forming a matrix having a first exterior surface and a second exterior surface; and 2) about 35 to about 70 percent, by weight, of activated carbon integrated into the matrix of pulp fibers such that the concentration of activated carbon adjacent the first exterior surface is at least about 60 percent, as determined by optical image analysis, and the concentration of activated carbon adjacent the second exterior surface is less than about 40 percent, as determined by optical image analysis, so that the filter is adapted to selectively reduce the C.sub.3 -C.sub.4 carbonyl component of conventional tobacco smoke at least about 25 percent more than a conventional cellulose acetate filter for an identical tobacco smoke. Also disclosed is a method of making the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.