การลดสัดส่วนรอยแตกบริเวณขอบยางในการผลิตยางล้อรถจักรยานยนต์

Abstract

The purpose of this research is to reduce loss from bead crack problem in motorcycle tire production which caused estimated average loss of a sample tire model 4 million baht per year by applying attribute and variable MSA technique to evaluate capability of inspectors, study problem characteristic in production processes, find causes of problem by using statistical approach and apply a three-factor Box-Behnken experimental design to find suitable level of each factor to solve the problem. Research result shows that causes of bead crack of case study tire model are green tire size, rubber compound quantity at bead area and green tire shaping steam pressure. After the experiment and standard improvement of production processes, bead crack ratio of a sample tire model was reduced and controlled from 7.23% to be 1.06% per month on average. Loss from bead crack was reduced more than 290 thousand baht per month or more than 3 million baht per year.