Filter for a cigarette and a filter-tipped cigarette
US6718989B1 · kind B1 · utility
19Cited by
28References
19Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Jul 24, 2000 |
| Grant date | Apr 13, 2004 |
| Priority date | — |
| Expiry date | Aug 7, 2020 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA24D3/04
- WIPO fieldOther consumer goods
- WIPO sectorOther fields
Abstract
A filter for a cigarette and a filter-tipped cigarette having a high degree of freedom in control of filtering-efficiency of smoke are provided. The filter has a core 10 and a sheath 12 made preferably of tow of cellulose acetate fibers. A plurality of axial passages 16 is formed between the core and the sheath and extend continuously between both end faces of the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.