British-American Tobacco Company Limited

Brown & Williamson Tobacco Corporation

British American Tobacco (Investments) Limited

Paul David Case

John A Luke

Alan George Stephenson

Martin Coleman

David John Dittrich

Colin Campbell Greig

John Lawson Beven

William John Stone

Peter R White

Stephen R Hemsley

Charles N Lehuquet

John Anthony Luke

Cigarette filter rod employs as filtration material moisture disintegrative paper. The moisture disintegration index of the paper does not exceed 20.

Smoking articles

The invention relates to a cigarette paper having a low total filler content, 20% by weight of the paper or less, a proportion of the filler being a filler capable of effecting visible sidestream smoke reduction. The basis weight of the paper is about 30 g m.sup.-2 or more. Smoking articles made with such papers provide a synergistic sidestream smoke component reduction when compared with control cigarettes. Papers according to the invention with the addition of various burn additives are also described.

Low filler content cigarette wrappers

The invention relates to a cigarette paper having a low total filler content, 20% by weight of the paper or less, a proportion of the filler being a filler capable of effecting visible sidestream smoke reduction. The basis weight of tbh paper is about 30 g m.sup.-2 or more. Smoking articles made with such papers provide a synergistic sidestream smoke component reduction when compared with control cigarettes. Papers according to thee invention with the addition of various burn additives are also described.

Tobacco smoke filtration material

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 making machine is provided with a pressure drop measuring unit (1) located at or close to the garniture of the making machine. The pressure drop of a gas stream of constant volume is introduced into the compacted tobacco rod beneath the format finger (2) on the making machine at a point at which that pressure drop measurement correlates with the bound pressure drop of the finished cigarette. The unbound cigarette pressure drop or draw resistance experienced by the smoker can be calculated using the bound tobacco rod pressure drop obtained by correlation with the measured pressure drop across the rod in an algorithim processed by calculation means. The degree of ventilation of the cigarette may also be utilised in the algorithim calculation. Comparator means allows the unbound cigarette pressure drop to be maintained within pre-set limits by varying cigarette parameters which affect the overall unbound cigarette pressure drop.

Measuring cigarette pressure drop

Low sidestream cigarettes having cigarette rods comprising paper wrappers including compounds of a type which effect a sidestream reduction of at least 30% when used on rods not exceeding 20 mm in circumference.

A cigarette having a wrapper comprising one to fifty percent by weight of calcium sulphate and/or calcium tartrate exhibits reduced sidestream smoke delivery and increased puff number.

Low sidestream cigarettes comprise cigarette rods not exceeding 20 mm in circumference. The cigarette rods comprise paper wrappers of a type which effect a sidestream reduction of at least 30% when used on rods of conventional dimensions.

Smoking articles in the form of a smoking material rod enclosed with a filter means by a paper wrapper are described wherein the density of the smoking material is in a range of from about 100 mg cm.sup.-3 to about 260 mg cm.sup.-3. The smoking material contains at least 20% by weight of expanded tobacco while the filter means has a filtration efficiency less than about 45% for removal of particulate matter. Ventilation means is operable to provide a ventilation level of at least 30%. Smoking articles in accordance with the disclosure exhibit acceptable mainstream smoke over the whole of the smoking process, i.e., there is less perception of an increase in mainstream smoke temperature.

Smoking article rod is made by extruding a tobacco/binder mixture, with the addition of water, to provide a rod form extrudate, under conditions such that the extrudate is of a cross-section greater than that of the die orifice. The extrudate is drawn down by, for example, passing the extrudate about two driven and peripherally grooved draw down drums.

Relating to the making of smoking articles

Low sidestream cigarettes comprise at least 20% expanded tobacco and a cigarette paper comprising a burn retardant.

Low sidestream cigarettes comprise at least 20% expanded tobacco and cigarette paper of an air permeability of not more than 20 Coresta units, the tobacco density being between 100 and 260 mg cm.sup.-3.

Growing community of inventors

Southampton, United Kingdom

Paul David Case