| 摘要 |
A filter for a cigarette includes a porous filter rod circumscribed by a porous or air permeable 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 thereof. The wall of each of the grooves defined by the wrapper is impermeable to air and smoke while at least a portion of the remaining area of the wrapper is air permeable. An air permeable tipping material circumscribes the wrapped filter rod which provides a path for ventilating air flow into the filter rod and a path for air flow into the grooves. Due to the air impermeable wall of the grooves, the air flowing in the grooves is segregated from the air and smoke flowing through the filter rod so that ventilating air is the only substance flowing in the grooves. The air flowing through the tipping material into the filter rod co-mingles with and dilutes the smoke flowing through the filter rod before it reaches the smoker's mouth. |
