| 摘要 |
An apparatus and method is adapted to provide the filter of a cigarette with an annular perpheral groove to enable air to pass directly into the fibrous body of the filter material after passing through apertures in the tipping paper. Ordinary plug wrap paper instead of a high porosity tea bag paper to wrap the fibrous filter material. The annular groove can be formed by a pair of rotating knives and a rotatable spacer with radial cutting edges which rout out material from each filter plug during conveyance of the plug on an alignment drum of a cigarette making machine. Alternatively, a plurality of closely spaced rotating knives which cut through the plug wrap paper only may be used to form a series of closely spaced annular grooves or slits in the filter periphery. |
