Pengaruh Suhu Pemanasan terhadap Plastisitas Karet Sir 20 di PT. Bridgestone Sumatra Rubber Estate Dolok Merangir

Abstract

Determination of Plasticity Retention Index (PRI) of Rubber SIR 20 has been conducted in PT. Bridgestone Sumatra Rubber Estate Dolok Merangir, where this analysis aims to know rubber plasticity and the elasticity of rubber mellowed in milling softener.Plasticity Retention Index (PRI) conducted with method of Wallace Plastimeter. Plasticity represent the comparison of plasticity value after warming-up and the first plasticity value before warming-up.From the analysis result done it will be obrained the value of Plasticity Retention Index (PRI) for SIR 20 about 80% on temperature 1250C, 79% on temperature 1270C, 77% on temperature 1290C, 75% on temperature 1310C. And from this result, hence, value of PRI the have fulfilled standard quality of specified rubber as according to Decree of Trade Minister of No. 184/Kp/VI/88, on 25 June 1988.