Cigarette filter contg. irregularly oriented fibres - comprises spun poly:hydroxybutyric acid or copolymer of hydroxybutyric acid and poly:hydroxy:valeric acid

摘要

A cigarette filter comprises a section of a fibre strand, compressed on the lateral axis, of irregularly oriented single fibres of spun polyhydroxybutyric acid (PHB) or a copolymer of PHB and polyhydroxyvalerianic acid. Pref. the single fibres have dia. 2-20 microns, and are generally longer than the filter. They lie at an angle of 30-45 deg to the lengthwise axis of the filter. The deg. of ventilation of the filter is above 40%. ADVANTAGE - The filter has good filter properties, but is relatively rapidly (i.e. during months) degraded under atmospheric conditions to harmless prods. e.g. CO2 and water. The taste of cigarettes is better than with cellulose acetate filters, or at the same intensity of taste, the cigarette smoke is more dil..