The Quality Improvement of Die Cut Machine: A Case Study of Sticker Roll Manufacturing Industry

Abstract

This research aims to improve the quality of the die-cutting process in digital label print production. At the beginning of the process improvement, the data collection of the defects and problem analysis with QC 7 tools were conducted. The check sheet, graph, and cause-and-effect diagram are the three QC 7 tools that are implemented to analyze the correlation between the die cutting speed, the die cutting force, the types of die cut, and the defects. The cutting process had the highest number of defects (60373.35 meters), accounting for 45 percent of all defects in the digital print production line. The conveyor speed and die cutting force observed from the process were 33 m/min and 30 psi, respectively, for all die cuts used in the production. In general, the die cuts can be separated into three groups: fancy, round, and circle. The defects based on the fancy, round, and circle die cuts were 27040.13, 15418.45, 17914.77 meters, or 44.79%, 25.54%, and 29.67% of the total defects in the digital print production line, respectively. Further investigation of the cause-and-effect of the defect shows that the conveyor speed and die-cutting force are not suitable for each type of die cut. Hence, the parametric study of the die cutting process based on the conveyor speed in the range of 31–34 m/min and die cutting force in the range of 29–32 psi was conducted. The experimental results show that the defects' number strongly correlates with the conveyor speed and die-cutting force. The minimum number of defects from the fancy-typed die cut was found at 32 m/min conveyor speed and a die-cutting force of 31 psi. The round-typed die cut was found at a conveyor speed of 31 m/min and a die-cutting force of 32 Psi, and the circle-typed die cut was found at a conveyor speed of 32 m/min and a die-cutting force of 30 Psi. The minimum number of defects for the fancy-typed, round-typed, and circle-typed die cuts was 453.74 meters, or 10.05% of 4,512.85 meters of production associated with the fancy type of 827.91 meters, or 10.88% of 7,606.89 meters of production associated with the round type, and 703.32 meters, or 11.37% of 6,187.52 meters of production associated with the circle type.