Packaging waste reduction by design of experiments

Abstract

The fl uorescent lamp manufacturer reports a high number of damaged inner packaging of straight fl uorescent lamp. This accounts for 8.43 percent of total packages. Consequently it is necessary to identify the factors that cause the inner packaging damage in order to reduce waste. The research begins by analyzing the overall auto packaging process. Then the fi shbone diagram is used to identify the root causes of the problem. It is found that there are fi ve possible factors; fl ute type of corrugated paper, corrugated paper storage method, hot melt adhesive temperature, hot melt adhesive injection pressure and hot melt adhesive fi lter replacement interval. Two-level full factorial experiment is employed to screen the signi fi cant factors. The result shows that all factors affect the occurrence of the waste at signi fi cant level of 0.1. Since the fi rst two factors have only two levels, the most appropriate levels of the last three factors are determined by using three-level full factorial experiment. The experiment results reveal that the most appropriate levels of those three factors can be achieved by setting hot melt adhesive temperature at 170 degrees Celsius, hot melt adhesive injection pressure at 1.2 bars and hot melt adhesive fi lter replacement interval at one week. When this new condition is implemented by setting corrugated paper to F fl ute and corrugated paper storage to plastic wrapping fi lm, the average amount of waste is reduced from 8.43 percent to 1.80 percent. This saving accounts for nine million baht per year.