Thesis (M.Eng.)--Chulalongkorn University, 2012

This objective of this thesis is to reduce the defect in coating process of aluminium composite panel. From the research, Defect has the large amount. That is affected to production process in many activities. Due to continuous production process, it wastes time and cost from defect that affected production seriously. Researcher operated by cause definition, cause analysis, improvement, reduction and control in coating process. This research studied in detail of coating process of aluminium composite panel and found the factor that affect coating process. The most quantity of defect is colour unlikeness. Design of experiment is created with 2 factors. There are temperature inside oven and roller Gap. Experiment is tested by statistical method and found significant factor. Cause and Effect Analysis Diagram uses for defining the real cause and effect. Temperature inside oven is the significant factor. Researcher found related method and reduced defect in coating process. After adjustment, researcher checks the result by checking on top of aluminium coil and tail of aluminium. Before adjustment data and After adjustment data are compared and analysed After improvement of coating process, it found that defect from colour unlikeness case; reduce from 23.99% to 2.45%. It reduces to 21.54%, which compares with before improvement data. It can be calculated 87.78% after improvement.