The Effects of the Properties of Materials in a Cigarette on Filter Ventilation

Abstract

A computer model was developed which makes it possible to predict the effects of several cigarette properties on the different degrees of ventilation (total degree of ventilation, degree of ventilation of the tobacco rod, degree of ventilation of the filter) and on the pressure drop. A special advantage of this model is its ability to predict the degree of ventilation from the properties of the materials (e.g. of filter, paper, tobacco) instead of from the properties of the manufactured cigarette. Thus it is no longer necessary to manufacture an experimental cigarette each time. Another advantage results from the fact that the fluctuations of the degree of ventilation can be attributed directly to the factors responsible. Each contribution of the individual factors responsible can be determined separately, which is normally not possible by means of experiments. Thus this model is not only a component of a computer-aided product design, but is also a useful tool for quality control. Some examples are presented which are typical of the effects of various properties of the materials on the ventilation. It becomes obvious that a low level of fluctuations of the filter ventilation does not only imply constant properties of the applied materials (such as tipping paper) but also a uniform primary process.

On an Optimal Choice of Pre-Perforated Tipping Paper and Porous Plug Wrap Paper

“…As the total area used in the permeability measurement of a perforated tipping paper is A m = 20 × 10 mm 2 , but the air permeable area is only A TP,m = 20 × w mm 2 we can calculate the local air permeability as needed in Eqn. [5] by This equation works well for electro-perforated tipping paper, but for laser-perforated paper, which has a series of N parallel perforation tracks, we can still use this equation with w = 0.5 $ N mm , which on the one hand gives a good agreement with experimental data and on the other hand reflects a typical spacing of 0.5 mm between the perforation tracks. For the plug wrap paper no such correction is necessary, because the entire 20 × 10 mm 2 are air permeable.…”

“…[5] is rather simple, some words are necessary how the permeability values in Eqn. [5] are related to measurements of the air permeability by the standard method described in ISO 2965 (9). Let k TP,m and k PW,m be the permeabilities of tipping and plug wrap paper, respectively, as measured according to (9).…”

“…For a given total permeability and a known tipping paper permeability the plug wrap paper permeability can be calculated by [6] which can simply be proven by back-substituting into Eqn. [5]. Eqn.…”

“…We assume that A PW = A TP such that the total permeability [5] can be assigned to the layered structure. For a given total permeability and a known tipping paper permeability the plug wrap paper permeability can be calculated by [6] which can simply be proven by back-substituting into Eqn.…”

“…In order to determine the necessary total permeability of the tipping/plug wrap combination, several mathematical models and computational schemes can be used, such as the ones described in (1-4), but for this study the total permeability will be assumed as given. The tipping paper permeability and the plug wrap paper permeability can then be calculated from the total permeability according to a model proposed in (5). In (5) the layered structure is modelled as two flow resistors with a linear pressure drop-flow relation switched in series.…”