| 摘要 |
A tobacco smoke filter, particularly for use with cigarettes, has a high filtration efficiency and novel construction, at least one end of the filter having an appearance similar to conventional filters comprising cylinders packed with crimped filaments or creped paper. The filter comprises a tube within which is a rod having an outer wall of filtering material and an inner part of supporting material. At one end the rod has the same cross sectional shape as the tube and is in engagement with the tube around its periphery, at the other end or between the ends, its cross sectional shape changes so that opposed surfaces of the filtering material engage each other, so that tobacco smoke drawn through the filter is constrained to pass through the wall of filtering material. The filter has a high efficiency at an acceptable pressure drop. |
