REDUCTION OF NONCONFORMING PRODUCTS IN PLASTIC-PACKAGING INDUSTRY USING 2k FACTORIAL EXPERIMENT DESIGN

Abstract

This purpose of this study is to reduce the total number of vacuum bags with surface defects exceeding specification limits by applying the design of experiment. The problem arose from inappropriate parameter settings of the film-blowing machine used in the production of vacuum plastic bags. The machine parameters were feed rate, melt temperature at the film-forming die, and the melt temperatures of three extrusion screws. The study used 2k factorial experiment design to identify the optimal parameters of the film-blowing machine. The results revealed that all the parameters exhibited main and interaction effects on surface defects of the product. The optimal parameter settings were feed rate of 485 kg/h, melt temperature at the film-forming die of 205°C, and screw melt temperatures of 185°C, 200°C, and 195°C, respectively. When these optimal conditions were implemented in the actual production, the nonconforming products with surface defects exceeding specification limits decreased by 11.04% compared with the pre-improvement process. The findings confirm that the systematic application of factorial experimental design can effectively enhance product quality and improve process consistency in the vacuum plastic packaging industry, thereby supporting sustainable quality improvement in manufacturing operations.