| 摘要 |
A filter for a smoking article comprises at least one plug of filter material surrounded by a plug wrap. The plug of filter material comprises at least two segments being longitudinally aligned and rotatably mounted about a common longitudinal axis, at least one of the segments comprising at least one perforation formed in the plug wrap to allow air intake into the filter in use. A tipping paper surrounds the plug wrap. The tipping paper comprises a first part attached to a first of the two segments of the filter plug and a second part attached to the second segment of the plug wrap and comprising at least one aperture formed therein, the tipping paper parts and filter plug segments are arranged such that the respective aperture and perforation of the tipping paper and the filter plug can be superimposed upon rotation of one of the filter plug segments about its longitudinal axis to vary the filter ventilation: At least one frangible capsule in the plug of filter material is provided, said capsule containing a substance for altering the characteristics of an air stream passing though the filter in use, wherein the at least one frangible capsule and the perforation and aperture in the filter plug and tipping paper are offset from each other longitudinally in the filter. |
