ENGINEERING JOURNAL CHIANG MAI UNIVERSITY

Volume 26, No. 03, Month DECEMBER, Year 2019, Pages 197 - 213

Reduction of touch dry problem of enamel paint

Phalatkorn Jaipongakkharakul and Napasssavong Osothsilp

Abstract Download PDF

The objective of this research is to improve a production process of Enamel paint. This research has an aim to reduce proportion of production cycles that needs quality improvement related to touch dry time over limit with the lowest the quality improvement cost. This research applied Six Sigma methodology, consisting of 5 phases: 1) Define phase: select and define important problem. 2) Measure phase: analyze the accuracy and precision of touch dry inspection system. 3) Analysis phase: brainstorm and select input factors for study, which were stirring time and drier quantity. 4) Improve phase: find out optimum stirring time using Two Proportions Z-Test and optimum drier quantity using Central Composite Design of Experiment (CCD). 5) Control phase: confirm experimental result after improvement and set up a control plan. After improvements, it was found that the proportion of production cycles that need unnecessary quality improvement over limit over one time reduced from 72% to 21% and saved the quality improvement cost of 171,084 bath per year.

Keywords

Enamel Paint, Touch Dry, Hypothesis Testing, Central Composite Design (CCD)

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