| 摘要 |
A filter for a cigarette includes a porous filter rod circumscribed by a non-porous or air impermeable wrapper, and ventilating air grooves embedded in the wrapped filter rod which extend from one end of the filter rod a preselected distance generally longitudinally of the filter rod. An air permeable tipping material circumscribes the wrapped filter rod which provides a path therethrough for ventilating air flow only into the grooves. The walls of each of the grooves defined by the wrapper, in one form of the invention, is permeable to air over virtually its entire length, and in another form of the invention is permeable to air flow only adjacent the mouth end of the filter. Under certain smoking conditions most, if not all of the ventilating air will flow from the grooves into the smoker's mouth through the open end of the grooves at the mouth end of the filter rod. Under certain other smoking conditions, at least a part of the ventilating air will pass through the air permeable walls, or portions thereof, of the grooves and into the filter rod wherein it co-mingles with and dilutes the smoke flowing therethrough. |
