A simple method for determining the puff profile of a cigarette was developed. This method was used to illustrate how the pressure drop of a filter may influence the puff characteristics of a filter-tipped cigarette. The pressure drop of the filter had a considerable effect, on the duration of a 35-ml puff when the cigarette was smoked on the well-known Bradford­type machine. Curves which represent puff profiles of filter-tipped cigarettes smoked on a machine which created a 35-ml puff of constant duration were also shown. Filters with three levels of pressure drop were evaluated by means of the two smoking machines. Cigarettes equipped with the filters were smoked, and the quantity of smoke solids which were trapped by the filter and which had passed through it were determined. The technique for determining these values was based on the fluorescence of the smoke. The results indicated that the amount of mainstream smoke generated by a filter-tipped cigarette was independent of its pressure drop and also independent of two types of smoking machines used. The efficiency of a filter, however, was found to be affected by the type of smoking machine used. In each case, the results obtained with the Bradford­type machine were about 10% higher than those obtained with the machine which controlled the puff duration.

(Full article published with kind permission from "Tobacco International")