Abstract
The effect of mechanical properties and rotating speed of screw on the feed rate was studied using aluminum hydroxide powder and calcium carbonate powder treated with stearic acid. In general, linear relationship was obtained between the feed rate and the rotating speed of screw although the linearity is somewhat weak for two types of untreated powder and those treated with 0.2wt% stearic acid. As the stearic acid concentration increased, the feed rate, that is, the slope of straight line α, increased. The aerated and packed bulk densities increased with the stearic acid concentration, implying that the flowability of powder was improved as the concentration of stearic acid became higher. The value of α was well correlated with the bulk density of powder collected at the outlet of screw feeder and the flowability measured by the shear tests and tensile strenght tests.
