| 摘要 |
1276933 Tobacco-smoke filters CELFIL CO ETAB 23 April 1970 [30 April 1969 24 March 1970] 19618/70 Heading A2C [Also in Divisions D1 and D2] A filter cord is made by passing a fibrecontaining web, e.g. of paper, through at least one nip between two rotating rolls, e.g. 8, 9, 10, with close intermeshing annular ribs which do not, however, contact each other, wherein, prior to its entry to the nip, the web is impregnated with an impregnant having a boiling point less than that of water, and a heat of evaporation less than 250 Kcal./Kg., freeing the web from impregnant, and cording the crimped web in a cording machine 41-49. The web may be freed of impregnant by evaporation, or by suction as at 15. Wrapper 47 is supplied to surround the filter, and the finished cord may be cut into filter rods. The impregnant may be a pure liquid or a solution. The solutions may contain dissolved substances, e.g. cellulose esters, cellulose nitrate, hydroysed cellulose, polyhydric alcohols, monovalent hydroxycarboxylic acids, monovalent carboxylic acids, and flavouring substances, e.g. hydroxy-substituted polycarboxylic acids, which remain in the material after removal of the solvent. A similar solution may also be applied prior to applying impregnant. The width of the paper web before cording can be adjusted by varying the amount of water in an impregnant/ water mixture. |
