การประยุกต์ใช้วิธีการ DMAIC สำหรับปรับปรุงกระบวนการผลิตสุขภัณฑ์เซรามิกส์

Abstract

This empirical study has objectives of improving quality of sanitary ware’s raw material and reducing preparation cost, utilizing a systematic problem solving concept of Six Sigma called DMAIC. In sanitary ware industry, energy is a determining factor of overhead cost which is 8.2 million Baht per year. The scope of study included ball milling process for sand, dolomite and pitcher and it aimed to find input factors that explain result of milling, the particle size distribution of less than 10 micron on the Laser Particle Size Analyzer. The analysis revealed ball ratio, %ball volume, %material volume, concentration, grinding speed (RPM) and milling time as critical contributors. Then 2^k factorial with center points experiment was carried out together with multi-factors linear regression analysis to obtain optimal process. The study was able to recommend setting of material volume at 39%, ball volume at 38% and reducing of milling time from 8 hours to 5.75 hours, which result in energy consumption reduction of 28% at a better quality of sand slip because of variation reduction in the particle size distribution.