Analisis Kualitas Ketahanan pada Crumb Rubber Mutu Sir 20 dengan Metode Plasticity Retention Index (PRI) di PT. Rubber Hock Lie Sunggal Sumatera Utara

Abstract

Plasticy Retention Index (PRI) is a measure of rubber's resistance to wear and tear or oxidation at high temperatures. The PRI value was measured from the comparison of the plasticity value of the rubber before being burnt (P0) and the plasticity value of the rubber after being burnt for 30 minutes at 140°C (P30). The Plasticity Retention Index (PRI) is a simple and short test carried out to measure the resistance of elasticity to degradation due to oxidation at high temperatures or wear and tear which is determined using the Wallace Plastimeter. The PRI test on the SIR 20 Crumb Rubber sample was carried out using the Wallace Rapid Plastimeter method. From the results of tests that have been carried out in the PT Rubber Hock Lie Sunggal laboratory are 74 ; 72 ; 70 ; 76 and 71. Based on the Regulation of the Minister of Trade no. 26 of 2021, one of which regulates the application of SPPT SNI 1903: 2017 includes technical specifications for natural rubber of Standard Indonesian Rubber (SIR), The Plasticity Retention Index (PRI) value which greatly influences the quality of rubber because the greater the value produced, the more resistant the rubber is to degradation. at high temperatures it will get better. . The results of this test indicate that the sample has met the quality requirements set by the government. A high PRI value indicates that rubber has a molecular chain that is resistant to degradation by oxidation. Meanwhile, a low PRI value indicates that rubber is easily oxidized to become soft rubber.