APPLICATION OF STATISTICAL PROCESS CONTROL (SPC) IN THE RUBBER INDUSTRY

Abstract

Statistical Process Control (SPC) is a more powerful tool available toimprove the manufacturing processes, to reduce scrap and rework, andultimately make the production more competitive in terms of productivityand preventing pollution. In this study, variable and range charts are used toevaluate the process of controlling drying tower temperature in the process oflatex crepe rubber production. The charts have upper and lower control limitsand the process is in control if sample measurements are between the controllimits. R chart was used to evaluate the variation of temperature within thedrying tower. In the case of charts for individuals, moving range charts and Xcharts were used in monitoring the process of daily chemical applicationssuch as sodium bisulphate, bleaching agents, and acids. Lack of control isidentified by the points laying outside the control limits on either the X-bar, Xchart, R-bar chart or R charts. Pattern of the time series interprets thevariation of the process. Runs test was applied to check up whether the timeseries is in the expected random order or not. Then Process Capability indexand the Process Performance Indexes were calculated to evaluate thecapability and the precision of the process. Therefore in the competitiveenvironment, statistical process control is a 'must' for achieving sustainabledevelopment in the rubber industry with high efficiency and effectiveness.