Abstract: A tobacco smoke filter comprising a rod of tobacco smoke filtering material incorporating particulate additive, wherein at least some of the particulate additive is concentrated on one or a restricted number of threads and/or strips incorporated within the remaining body of filtering material, the additive adhering to said thread(s) and/or strip(s).

Abstract: A cigarette filter comprising longitudinally aligned core components a first of which is air-permeable and of relatively high pressure drop longitudinally of the filter but substantially air-impermeable radially of the filter and a second of which is air-permeable and of relatively low pressure drop longitudinally of the filter, and a common wrap or partial wrap which extends along and around or partially around said core components and provides for ventilation of the filter at a region longitudinally spaced from the first core component.

Abstract: A tobacco smoke filter having a non-integral core of components [2, 3] joined and held in longitudinal alignment by a strip [1] which extends only partially around the core circumference to leave a gap [7] extending longitudinally of the core between the longitudinal edges [8] of the strip, and an outer wrap [5] which engages fully around the core and strip and provides--e.g. via perforations [9]--for the lateral ingress of external ventilating air therethrough and through the longitudinal gap.

Abstract: This invention provides a smoke filter element comprising a filtering core, a smoke impermeable wrapper in surrounding engagement with the core, at least one internal passage defined between the impermeable wrapper and core and open at an end of the element, and at least one external passage defined by the outer surface of the impermeable wrapper and extending to an end of the element; and a cigarette filter comprising such an element having engaged around said impermeable wrapper tipping material which provides, when the filter is drawn on in use, for the ingress of external air laterally therethrough into said external passage(s). The tipping material may be a tipping overwrap incorporating the filter in a filtered cigarette. The impermeable wrapper may have longitudinal corrugations providing the passages, which may extend fully or only partially the length of the wrapper.

Abstract: This invention provides a cigarette filter comprising a filter core (2), a plugwrap (4) around the core, a profiled spacer wrap (6) around the plugwrap, and tipping material (8) around the spacer wrap, the profiled spacer wrap providing between the plugwrap and tipping material passages (14,16) which are in lateral air flow communication and extend longitudinally of the filter to open at an end thereof, the tipping material providing in use of the filter for the drawing of external air therethrough directly into at least some of the said passages, and the plugwrap beneath the passages being smoke-impermeable. The spacer wrap may be longitudinally corrugated to provide adjacent longitudinal passages (14,16) which are in air flow communication via apertures (15) through the side walls of the corrugations.

Abstract: Tobacco smoke filters comprising a rod of tobacco smoke filtering material, such as cellulose acetate tow including a thread incorporated therein or a tape wrapped therearound, the thread or tape carrying a smoke-modifying agent, such as a flavoring material and methods and apparatus for forming such filters.