Cigarette filter - formed by coaxial tubes with intermediate corrugate element defining particle retaining and smoke filtering channels

摘要

Tobacco smoke filter having a higher retention of smoke constituents than conventional filter is formed two coaxial tubular elements defining an annulus in which is disposed a corrugated intermediate element forming axially extending channels which are closed adjacent the cigarette end and open adjacent the mouth at which the inner tubular element is closed by plug such that the smoke from the cigarette end permeates the inner tubular element to enter the channels, the channels carrying >50% of the smoke volume, the remainder part of the volume being made up by air permeating the outer tubular element. Inner tubular element may be formed from bonded fibres, threads, strips, formed or porous plastics materials, paper or webs woven from endless fibres; pref. cellulose acetate or polyolefin fibres are used.