Waste reduction in plastic bottle manufacturing for drinking water industry

Abstract

The purpose of this study was to improve the quality of plastic water bottle by focusing on reducing the
amount of waste. This study began with the determination of symptoms and causes of the problem by
analyzing types and amount of waste with 7 quality control tools (7 QC tools). The results from 7 QC tool
analysis showed that one of the most important symptoms of the problem was bottle scratching caused by
bubble in plastic pre-form tube after receiving from the injection molding process. The technique of 2k
factorial design was used to study the effects of three process factors (i.e., temperature at the three
machines in the drying process of plastic pellets) on the amount of waste. The results showed that
temperatures were significant and the optimal operating conditions of the significant factors were at the high
level of each of the temperature. Moreover, at the optimal operating conditions, waste of bottle scratching
was reduced from 0.248% to 0.18%.