Abstract: A method is disclosed for producing tobacco smoke filters wherein a continuous tube of smoke filtration material is ensheathed in a smoke-pervious layer of fibrous material. The ensheathed tube is cut into discrete lengths and in each of the lengths a cross section of the ensheathed material is rendered impervious to the passage of tobacco smoke and the tube is closed at a distance spaced longitudinally from the cross section.

Abstract: The invention concerns a method for modifying the peripheral conformation of a cigarette, which has an external, heat deformable, wrapper comprising a proportion of thermoplastic fibers or filaments. The method comprises the application of heat to the wrapper. Heat is applied by a heat forming means moved relatively and in contact with the cigarette, in a direction transverse to the longitudinal axis of the cigarette.

Abstract: For manufacturing rod for cigarette use, rod filler and paper wrapper web are fed continuously to a rod-forming machine in which wrapper web is wrapped about said filler to provide rod and the wrapper is longitudinally lap seamed by bringing heated sealing means into contact with the outer of overlapping web portions intended to provide the seam, one at least of said portions comprising at least 50% by weight of thermoplastic fibers or filaments. The rod filler and paper wrapping web, comprising at least 50% by weight of thermoplastic fibers or filaments, may be fed to the rod-forming device with the margins of the web overlapping and the heated sealing means brought into contact with one of the overlapping margins. The machine may be a cigarette-making machine or a filter-rod making machine.

Abstract: A smoke filter for a smoking article (e.g. a cigarette) comprises a filter plug having ducts extending partway along the plug from the mouth end thereof, and opening in register with inlets through wrapping means around the plug to provide segregated peripheral venting of the filter.Further apertures in the wrapping means communicate directly with the filter plug away from the ducts to permit ambient air to enter the filter plug to mix with and dilute the smoke being filtered within the plug.

Abstract: A smoke filter for a smoking article (e.g. a cigarette) comprises a filter plug having an airflow duct whose floor extends along the filter plug from the mouth end of the plug such that the end of the duct remote from the mouth end is deeper than the end of the duct at the mouth end, with a region of progressively decreasing depth from the deep end towards the shallow end. The at least one duct may comprise a plurality of grooves equiangularly spaced around the periphery of the filter plug, in which case it is possible for the grooves to extend helically and to be divided into sets of opposite hand such that each groove of one set intersects several grooves of the other set. Alternatively, the airflow duct may comprise a single annular groove extending around the filter plug with a shallower side at the mouth end of the plug and a deeper side remote from the mouth end, in which case a relatively stiff tipping is required.

Abstract: The filter comprises a tobacco smoke filtration tube ensheathed in a layer of smoke pervious thermoplastic material. The layer is encased in a plugwrap. The layer has a transverse cross-section rendered impervious to smoke tobacco by use of an annular sealing groove. The tube is closed at a location spaced longitudinally from the groove by a V-shaped annular groove.

Abstract: A rod-form body of smoke filtration material, preferably fibrous or filamentary, is wrapped in a fibrous or filamentary plugwrap comprising at least 50% by weight of fibres or filaments of thermoplastics material. The plugwrap may have premeability for air of not less than 10,000 Coresta units. The majority, suitably at least 80% by weight, of the material of the rod-form body is a material other than the said themoplastics material of the plugwrap. Thus the smoke-filtration material may comprise crimped polypropylene tow and the plugwrap be composed substantially wholly of fibrous cellulose acetate or conversely. Portions of such filter rod may be subjected to a hot-shaping process to provide grooved filter elements.

Abstract: For producing rod-shaped tobacco-smoke filter components each having one or more annular tobacco-smoke barriers, annular grooves open at their peripheries are formed in rod-shaped bodies of smoke-filtration material, the grooved bodies are conveyed in a direction transverse to their longitudinal axes along an arcuate path, and settable barrier material is deposited in the grooves during the conveyance along said path, the bodies being rotated about their said axes during the deposition of the barrier material.

Abstract: The invention relates to the treatment of fibre, particularly for making rods of bonded, fibrillated polyolefin fibre which can be used for example as or in tobacco smoke filters. The fibres may be crimped or straight and are bonded with a polymeric or copolymeric bonding agent which is applied to the fibres without the application of heat, the bonding agent being in the form of a cold setting emulsion, applied for example by means of a shear cone rotating at high speed or by brush means, the treated fibres then being formed to shape and allowed to cure in normal conditions and in the absence of heating.

Abstract: A tobacco-smoke filter comprises a plug of filter material of which a transverse cross section is impervious to the passage of smoke except for a minor proportion of the area of that cross section which forms a smoke-accelerating orifice, the plug being enclosed by an envelope permitting ingress of air into a region of the plug downstream of the orifice. The cross section may be impervious because of the presence of a barrier diaphragm of impervious material. Thus an annular groove may be provided in the plug at the cross section and may be filled with, or have its walls coated with, an impervious material. Alternatively the cross section may be impervious by reason of the closure of interstices in the filter material by the local application of heat thereto.

Abstract: A tobacco-smoke filter has a filter body comprising at least one intermediate section which is located between end sections, has a cross section less than that of the end sections and lies wholly within the outline of the latter sections as viewed axially of the body, and a porous wrap of sheet material which is pervious to volatile constituents of tobacco smoke and which bounds, with the said body, at least one space affording a path through which smoke can pass when the filter is in use and from which said constituents are removed fom the smoke by diffusion through the said sheet material, each of the said sections being made of filter material. Suitably the body is of generally cylindrical form and composed of cellulose acetate. Advantageously the intermediate section is integral with at least one end section.

Abstract: For shaping a component of a smoke filter, a rod of the material to be shaped and a heated former are relatively moved in contact with each other, in an arcuate path, in a direction transverse to the longitudinal axis of the rod, whereby an impression, for example an annular or helical groove, is produced in the rod by the former. For the said relative movement, the rod may be supported at the periphery of a rotor, while the former comprises a heated arcuate stator element or elements projecting inwardly towards the rotor. The rod may be turned about its axis during the relative movement, for example by a pair of rollers by which it is supported at the periphery of the rotor. A surface or surfaces bounding the impression, for example the bottom surface of a groove, may be sealed, during the shaping operation, so as to be smoke-impervious.

Abstract: A filter element for a smoking article, such as a cigarette, comprises a generally cylindrical body having at least one helical groove in its peripheral surface and closely wrapped in a material pervious to vapor-phase constituents of the smoke, whereby such constituents are removed by diffusion thereof through said material during passage of the smoke along the groove. The body may be wholly or in part of a filter material capable of removing particulate-phase constituents from the smoke during its passage through the element. Suitably the groove extends from the upstream end face of the body to a point short of the downstream end face, where it opens into a space separated from the downstream end by an ungrooved portion of smoke-filter material. One or more faces of the groove and/or said upstream end face may be partially or wholly sealed against penetration of smoke into the body.

Abstract: The invention relates to a method for wrapping a continuous filter rod and producing tobacco-smoke filter sections which comprises feeding a wrapping strip of a thermoplastics film material, particularly a heat-shrinkable thermoplastics material, past an applicator for applying adhesive to the edges of the strip and, together with a filtering medium, to garniture means for wrapping the said strip around the said medium, which means includes a sealing station consisting of or comprising a cooled long folder, provided with a semicylindrical groove closely matching the rod size and of a length sufficient to permit setting of the adhesive to form a seam between the said edges, and feeding the wrapped rod thus produced to a cut-off device with guiding means for the cut-off sections. Preferably the adhesive is a solvent for the thermoplastics material.