Wear of Rice in an Abrasive Milling Operation, Part 1: Prediction of Degree of Milling

The abrasion coefficient of rice was determined at different degrees of milling levels, for three varieties of rice differing in slenderness ratio. The abrasion coefficient was found to decrease with the degree of milling, indicating the removal of asperities and progressive hardness of the core of the rice. The slenderness ratio was found to be negatively related with the value of the abrasion coefficient. The average values of the abrasion coefficient of rice on abrasive element (synthetic emery) varied between 0·03 and 0·05 for three varieties of rice differing in hardness and slenderness values. The average value of abrasion coefficient was used to predict the degree of milling using the principles of adhesive wear. The predicted values of the degree of milling fitted the experimental values adequately, with relative deviation modulus varying between 14 and 23% and good values for the coefficient of determination (R2>0·90).