圧力伝達の基礎的理論式に基づく湿潤粉体の特性解析

摘要

In this study, compression test was applied to evaluate theological characteristics of wet powder. Various quantities of moistened lactose monohydrate and microcrystalline cellulose were compressed in a cylinder. Relationships between compression transmission rate p_T/P and dimensionless sample height H/D under various compression pressures P were fitted to a theoretical pressure transmission equation of p_T/P = exp(-4μKH/D). As a result, high correlations were obtained between them, indicating that pressure transmission of wet powder behaved as the ideal condition. The stress applied to the cylinder inner wall during the compression test was measured using strain gauges attached to the cylinder wall and friction coefficient of the wall surface μ and Rankine coefficient K were calculated. Consequently, the behaviors of μ and K under various compression pressures, liquid contents and liquid viscosities were investigated. From these results, it was suggested that the method proposed in this study could estimate a state of the wet powder under pressure.%粉体の取り扱い，その装置の設計等において，粉体層のレオロジカルな性質，すなわち内部摩擦角，安息角，付着力等を評価するため，古くから多くの研究がなされてきた。さらに粉体は湿潤するとその弾性，粘性，付着性等の特性が大きく変化することから，湿潤粉体に関しても同様に多くの研究が行われている。