Improvements in or relating to Filters for Cigarettes.

摘要

1,170,174. Composite tobacco-smoke filters. D. W. MOLINS. 21 Aug., 1968 [22 Aug., 1967], No. 38582/67. Heading A2C. A method of making a composite tobacco-smoke filtering rod having a particulate filtering material enclosed in a space defined between two smoke-permeable cylindrical elements within a tubular wrapping includes the step of causing the two elements to be relatively displaced to reduce the volume of said space and there by increase the degree to which the material packs the space. Preferably the wrapper is coated with a heat sensitive adhesive to allow heat sealing of the elements to the wrapper after displacement of the elements therein. Where the two elements are filter stubs, one may be moved towards the other inwardly of one end of the wrapping to define a recessed end face, which recess may subsequently be removed by cutting through said one element which should originally be oversize to allow for this. The two elements may alternatively be a filter stub and a wrapped tobacco rod whereby a filter cigarette is directly produced. Where double length composite filter stubs are to be formed, the outermost element at each end is displaced inwardly.