APPARATUS, METHODS AND PRODUCTION OF CIGARETTE FILTERS

摘要

The filter comprises a tobacco smoke filtration tube ensheathed in a layer of smoke pervious thermoplastic material. The layer is encased in a plugwrap. The layer has a transverse cross-section rendered impervious to smoke tobacco by use of an annular sealing groove. The tube is closed at a location spaced longitudinally from the groove by a V-shaped annular groove.