process for the production of filterstäben or from these by subdivision of emerging filterstöpseln for tobacco and manufactured filtergegenstand than

摘要

1336889 Tobacco-smoke filters CEL FIL CO ESTABLISHMENT 27 May 1971 [29 May 1970] 17572/71 Heading A2C [Also in Division D2] Filter plugs for tobacco products are obtained by crimping cellulosic paper web longitudinally as described in Specifications 790964 and 832087, sheathing the web to form an endless filter cord and dividing the cord into plugs, the process being characterized in that prior to conversion into the cord and before or after crimping the paper web is treated with an impregnating agent which chemically modifies at least part of the surfaces of the cellulose fibres of the paper, the excess impregnant being removed. The cellulose may be converted to a cellulose ester e.g. cellulose acetate, acetate butyrate, or acetate propionate by treatment with the appropriate acids and their anhydrides in water, methanol or acetone in the presence of H 2 SO 4 or ethyl cellulose by treatment with caustic soda and ethyl chloride. The impregnant may be applied by a roller applicator or by spraying. In the apparatus shown in Fig. 4 a paper web 1 has a volatile liquid 6 applied by roller 5, the paper is crimped and heated by rolls 8, 9, 10, impregnant is sprayed onto the web by nozzle 40 (the medium for the impregnant 'being readily volatile if not a drying station being provided) and the crimped and impregnated web is sheathed to form a filter cord at 41-49 by strip 48. If desired liquid 6 or a similar bath down line thereof may supply the impregnant.