| 摘要 |
A cigarette filter element comprises a core (4, 10) of relatively high or infinite pressure drop material. Around the core a longitudinally grooved or corrugated wrapper or integral surface region (3) provides channels (1, 2) which extend from end to end of the core out of communication therewith and which, when the wrapper or skin is in turn surrounded by tipping material (7), are of less pressure drop longitudinally of the element than the core. <IMAGE> |
