Analisis Konsistensi Mutu Crumb Rubber di Pabrik Karet PT.Bridgestone Sumatra Rubber Estate

Abstract

Maya Sari : The analysis of Quality Consistency of Crumb Rubber at the Rubber Factory of PT.Bridgestone Sumatra Rubber Estate. Under the supervision of SAIPUL BAHRI DAULAY and ACHWIL PUTRA MUNIR. Natural rubber is one of the agricultural commodities which support the economics of Indonesia. One of the natural rubber production is crumb rubber. Nowadays the improvement of rubber consumption just depend on the high consistency and uniformity of the product. Therefore, to know and to control the consistency of crumb rubber at PT.Bridgestone Sumatra Rubber Estate, a quality consistency analysis of the crumb rubber produced is needed. The analysis that had been done in this study was statistical control technique using controller map and cause-effect diagram. Data of Original Plasticity (Po) and Plasticity Retention Index (PRI) in March 2006, January 2007, January 2008, June 2009 and January 2010 were used. The study indicated that Po of the crumb rubber production on March 2006 and January 2008 were not undercontrol with the average of 32.9psi and 32.613psi, while on January 2007, June 2009 and January 2010 were undercontrol with the average of 32.55psi, 33.613psi, and 33.225psi. respectively. The PRI of the crumb rubber on March 2006, January 2007, January 2008, June 2009 and January 2010 were undercontrol and stable with the average of 77.975, 78.638, 78.413, 79.463, and 80.15. respectively.