Defects reduction in corrugated paperboard manufacturing process

Abstract

This research utilized the application of Six Sigma method to reduce defect in corrugated paperboard production process. Percentage of defect is used as the indicator to measure improved performance. This research followed DMAIC Six Sigma approach that is divided into 5 phases. First, Define phase, the project chapter was set up consisting of statement of problem, objectives, scopes, and team members. The defect data was collected from February to March 2014. Findings show that the corrugated paperboard production process created the greatest defect, mainly blister defect, which is 2.87% of total production volume. Second, Measure phase, the measuring system was analyzed and the result met the acceptance criteria. Then, all possible causes were identified by brainstorming within the team and prioritized until merely four factors remain. Third, Analyze phase, analysis was done on the four factors by using statistical method and it was verified that the four factors contributed to occurrence of blister defect. Forth, Improve phase, full factorial design of experiment was applied to test the significance of factors affecting the blister defect, as well as to find the optimum of each factor. The last, Control phase, the control plan was updated to control the setting of the four factors at the proper level using check sheets. In addition, the control chart was set up to monitor the stability of blister defect and to eliminate the special causes.

After the implementation, the average blister defect from corrugated paperboard production process is reduced to 1.89%, which was calculated as 34.14% of defect reduction.