An effect on NT ratio by filtration of cut tobacco
Some variations in Tar and Nicotine are observed as a result of manufacturing activites, and accordingly their ratio ("NT ratio") varies for a tobacco product. As factors of such variances, we have studied cut tobacco weight and pressure drop and we investigated their effects on tar and nicotine yields and NT ratio from a standpoint of quality assurance. In our study, tar and nicotine yields of the cigarette were measured in accordance with ISO 3308 and 4387, the pressure drop was measured with ISO 6565, and the data was processed statistically to investigate the effects of such factors. The results showed that tar and nicotine yields increased according to the increase of tobacco weight. On the other hand, tar and nicotine yields were reduced while pressure drop increased. It is assumed that this tendency was caused by a change in generation of particulate matter or filtration efficiency in the tobacco rod. We also studied the relationship between the NT ratio and void ratio (i.e. cut tobacco volume / tobacco rod volume) on the same cigarette. The NT ratio was reduced nonlinearly according to void ratio and we found that there are stable regions in NT ratio values. This is attributed to different filtration efficiencies for tar and nicotine yields in a tobacco rod.