BUBBLE DEFECT REDUCTION IN ROTOCAST AREA OF PT. XI BY USING FULL FACTORIAL DESIGN OF EXPERIMENT

Abstract

PT. XI is a doll manufacturer located in Jababeka area, Cikarang. One of the most important processes in making doll is the process to produce the doll’s head. More than 50% of the head is exposed directly to the customer and less than 50% of it is covered either with hair or paint. If there is a defect on the head, the customer will notice it immediately and thus it will be counted as a defective product. Therefore, maintaining the quality of the doll’s head is very crucial to the company. One of the most common defects is called Bubble that contributes 31% of the total defect in rotocast area. Therefore, this defect is used in the research and analyzed using experimental design which is the 23 factorial design with the objective are to find the significant factor and to find the optimum machine setting to reduce Bubble defect. Bubble defect is chosen as it has critical level of seriousness level. The research is more focused on rotohead 1166 by using Pareto chart analysis. The factors for experimental design are chosen by using Fishbone diagram. By using experimental design, the optimum machine setting that reduces Bubble defect are oven time 125 seconds, cycle time 180 seconds, and oven’s temperature 240 °C. By applying the proposed machine setting, the company can increase its profit by 64.88%.