抄録
The apparent density of cut tobacco is one of the most important physical properties, because it has a high correlation to the bulkiness (Filling value) relating closely to the reduction of materials in cigarette production. In addition, it is related to the burning characteristics of cigarettes which have a great influence on the taste and aroma of smoke, and to the conditions of separating, transporting and drying processes of cigarette making. However, the conventional measurement method (the oil impregnation method) has the disadvantages of long operating time. For a rapid and convenient measurement of apparent density, the “mercury displacement” method was investigated using the large mercury surface tension. And the results obtained are as follow.
1) The apparent specific volume of cut tobacco in the pressure range of about 200 to 300g-f/cm2 was recognized to be in the nearly costant state, though it slightly decreased with the increase in pressure. The apparent density of each sample obtained under the pressure of 250g-f/cm2 agreed with the value by other methods, and it was adopted as the standard pressure in this method.
2) Under the standard pressure, it was confirmed experimentally that the mercury would not enter into the concave surface and the pore of diameter less than 60μm. And the pore of diameter above 60μm could not be observed in the surface of ordinary cut tobacco.
3) The values of apparent density and their accuracy obtained by this standardized method were almost the same as those obtained by the conventional method. The time required for this operation was about 15 min, which was one-third for the time of the conventional method.
4) The apparent density of cut tobacco consisting of the ordinary grain size distribution could be measured exactly by the pressure of 250g-f/cm2 and sample weight of 1-2g (in case of 25cm3 sample cell) as the standardized procedure.
