British-american Tobacco Company Limited

Peter R White

Paul David Case

Martin G Duke

Colin Campbell Greig

John Lawson Beven

Martin Coleman

An extruded filtration material which is degradable and comprises either a plastics material or an inorganic material having a melting point above the operating temperature, a polysaccharide expansion medium, a binder and water. These ingredients are fed to an extruder and subjected to an extrusion process which involves a pressure reduction, upon extrusion from the exit die, of up to about 70 bars so that swelling of the extrudate occurs to give a cellular structure. When exposed to the natural weather conditions, tobacco smoke filter elements comprising such material degrade without leaving a fused amalgamation of plastics or inorganic material.

Filtration materials

A cigarette having a region having means to reduce the vapour phase constituents of tobacco smoke, such as carbon, surrounding a tobacco smoke flow path is provided with ventilation means to channel the tobacco smoke away from the vapour phase constituent reducing region. The vapour phase constituent reductions achieved are greater than the reduction which would be expected in view of the degree of ventilation to which the cigarette is subjected.

Relating to smoking articles

A method of making a ventilated cigarette filter plug in which a bore is thermally formed, by a laser beam for example, in a rod comprising a duct extending coaxially of the rod and matrix material surrounding the duct. The thermally formed bore extends through the matrix material to provide air-flow communication between the periphery of the rod and the interior of the duct.

Growing community of inventors

Romsey, United Kingdom

Peter R White