粉体の圧縮成形に関する研究(第2報)塩化カリウム粉体の臼圧縮における下杵への圧力伝達

抄録

To study the compression characteristics of powders, 0.15-3.0 g of potassium chloride powder (42-65 mesh) was poured into the cylindrical die of 8.02 am inside diameter, and compressed from one side by the upper punch under a constant upper punch pressure (about 1000 kg/cm² in the maximum). After compressing for 10 min, the thickness of powder bed and the lower punch force were measured. . By Janssen's theory, where the ratio K of the horizontal to the vertical pressure and the coefficient μ of friction on the die wall are regarded as constant, the ratio P_L/P_U of the lower to the upper punch pressure should increase monotonously with the decrease of the thickness of powder bed at the constant diameter of powder bed. When a constant weight if potassium chloride powder was compressed, the ratio P_L/P_U varied complicatedly with the increase of upper punch pressure. These functions were determined from the assumption of K and μ as the functions of pressure, and from the comparison of the pressure-porosity relationship in hydrostatic compaction with that in die compaction. Using these functions, partial revision of Janssen's equation Was made.