| 摘要 |
1321820 Tobacco-smoke filter CIGARETTE COMPONENTS Ltd 22 Dec 1970 [24 Dec 1969 21 March 1970] 62856/69 and 13767/70 Heading A2C The filter comprises a tubular outer member 3 housing an air permeable rod 2 having a circumferential wall 6 of filtering material that encloses an air permeable supporting core 7, the outer surface of the wall 6 being in smokesealing engagement with the member 3 at a first longitudinal position 10 and opposed portions of its inner surface being deformed towards one another with compacted core material therebetween in smoke-sealing engagement at a second position 11 longitudinally spaced from the first, so that smoke drawn through the filter passes through the wall 6. The rod 2 is deformed to form grooves 15 in a substantially cylindrical intermediate portion 14 and to form ribs 12 at position 11 which may be cruciform (as shown) or may be in the form of a "Y". In an alternative embodiment, the filter rod has two cylindrical ends with a central section of "Y" cross-section, and the space between the central section and the outer member may be filled with granular material. In a further embodiment, the filter rod has a central cylindrical section and the two ends are of cruciform cross-section. The filtering material may be air permeable paper, bonded fibres or filaments, or porous plastics. The supporting part may be formed from a bonded cellulose acetate tow, a creped porous paper web, or fibres or filaments of thermoplastics such as polypropylene or polyethylene. A suitable apparatus (Fig. 5, not shown) is disclosed in which the filter is made by wrapping a filamentary tow (51) of cellulose acetate, that has first been sprayed with triacetin, with an elongate strip of paper (61) to which bands of adhesive have been applied and then heat deforming the resultant rod (65) to form a rod (67) comprising alternating portions of circular and cruciform cross-section. The rod (67) is then overwrapped either before or after cutting off through the centre of each portion to complete the filter. |
