SMOKING ARTICLE FILTER VENTILATION

摘要

A filter for a smoking article such as a cigarette comprises a core, a wrapper surrounding the core, and at least one ventilation hole extending though the wrapper into the core to a depth such that air drawn in through the ventilation hole enters a central region of the core. The ventilation holes may be configured so that air preferentially enters the central region compared to the periphery of the core, and may have a depth in the range 2 - 3.5 mm.