Flow Pattern of the Dispersed System of Tobacco Powder and Water during Extruding V.

Factors Affecting on Apparent Viscosity

Abstract

To clarify the factors affecting apparent viscosity η_a of tobacco powder-water systems and to formulate an emprical equation for η_a experimental results are rearranged, and supplementary tests have been conducted for the pressure transmittances for those of Bright Yellow-water systems and of Matsukawa-water systems. The following results have been obtained;
The ratio of pressure transmittances changed remarkably at 0.13 in moisture content for Bright Yellow-water systems, and at 0.20 for Matsukawa-water systems. These values are smaller than those of the systems of each residues by 0.25~0.23.
Dependencies of η_a on shear rate are expressed by Cross's equation. However, m=2/3 is inadequate to represent the results, in this study. Good agreement between experimental results and the equation is found at m=0.70~0.85. Dependencies of η_a on volume fraction are expressed by Eilers's equation. For the upper limit of volume fraction,φ_m employed is the volume fraction at the critical moisture content which is estimated from the transmitting characteristics. Dependencies of η_a on temperature are expressed by Andrade's equation. Constant B is determined for the systems of two types of tobacco, and B increases according to the decrease of ψ.