Effect of Hopper Angle and Teeth Density on Performance of Cylinder Type Sago Rasping Machine

Abstract

Rasping is the most frequently useful method to disintegrate or to break down the cellular structure of sago pith for mechanical processing. The objective of this study was to investigate the effect of hopper angle and teeth density on rasping performance of cylinder type sago rasping machine. In the experiment, three levels of hopper angle i.e. 0° (H1), 22.5° (H2) and 45° (H3) and three levels of teeth density i.e. 2.2 cm × 4 cm (D1), 2.2 cm × 3 cm (D2), and 2.2 cm × 2 cm (D3) were examined. The rasping performance test was carried out by measuring rasping capacity, starch percentage, and starch yield. The experimental results showed that the combination of hopper angle and teeth density significantly affected rasping capacity and starch yield, but did not affect the starch percentage. The highest rasping capacity (1891 kg/hour) and the highest starch yield (790 kg) were resulted under experimental condition of teeth density 2.2 cm x 3 cm with hopper angle of 22.5 degree. In conclusion, the optimum condition to achieve highest rasping performance was teeth density 2.2 cm x 3 cm with hopper angle 22.5°.