British-american Tobacco Company Limited

John D Green

John A Luke

Henry G Horsewell

Philip John Kinnard

Raymond J Harrison

Ian R Harris

Stanley M Candlish

In a method of making lengths of smoking-material rod, particularly cigaret lengths, smoking material and wrapper-web material are each continuously fed to a rod maker operable to wrap and seam-seal the wrapper material about the smoking material to provide smoking material rod which is then fed to a cutter for cutting the rod into lengths. Smoke-modifying agent is applied by spray intermittently to one of the materials during their feeding to the rod maker so that, in each of the lengths, the smoke-modifying agent is distributed over one end zone which is accounted for by a few puffs, in the smoking of the length. The smoke modifying agent is of low volatility and low porosity migration.

Making of smoking articles

A smoking article, such as a cigarette, has a filter which incorporates a volatile smoke-modifying agent. The filter comprises zeolite granules impregnated with the volatile agent. A cavity-type of filter may contain between 10 and 200 mg of mentholated zeolite granules. The loading level of a menthol on the zeolite granules may be within a range of from 3 to 60 mg/g. Cellulose-acetate plugs may be provided at the ends of the filter cavity.

Smoking articles

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.

Tobacco-smoke filters

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.

An improved tobacco-smoke filter or filter material contains granules of porous activated carbon to which has been applied a nitroxide of the group consisting of the nitroxide 4-oxo-2,2,6,6-tetramethylpiperidino-oxy, the nitroxide 1-nitronyl-3-oxyl-4,4,5,5-tetramethyl-2-phenyldihydroimidazole and mixtures thereof. The carbon may be loaded with 0.5 to 25%, suitably 1.0 to 15%, by weight of the nitroxide. Advantageously such a filter has provision for filter ventilation. For instance, in a triple filter with a center section containing the treated carbon, the said center section and/or the section upstream thereof is ventilated.

Growing community of inventors

Romsey, United Kingdom

John D Green