Pemanfaatan karet riklim dari skrap rubber roll untuk kompon sol sepatu

The objective of the research was to study the effect of the used reclaim rubber from scrab rubber roll as a rubber substitution at rubber compounding for shoe sole production. The reclaime rubber was made by mixing between 100 part scrab rubber roll, 30 part reclaiming oil and 2 part reclaiming agent. The mixture was aged to swelling process for 24 hours and devulcanization was conducted at 1500C for 1.5 hours. Properties of the reclaim rubber were identified such as tension at break 46.55 kg/cm2, elongation at break 136.22%, hardness Shore A 52.8, acetone extract 30.4% and polymer contain 36.41%. The rubber compound was made by using special natural rubber of RSS I (Ribbed Smoke Sheet I) mixed with reclaim rubber at ratio of 100/0, 90/10, 80/20, 70/30, 60/40 and 50/50 phr (part hundred rubber) respectively and was also added additives. The mixing was conducted by using mixing mill at 400-600C for 50 minutes. The compound was concluded that the composition between new rubber RSS I and reclaim at the ratio 70/30 has obtained the most favorable physical properties, with respected testing result of tention at break 85.5 kg/cm2, elongation at break 195.3%, hardness 72.2 shore A, tear resistance 42 kg/cm2, permanent set at 50% elongation 0.27%, density 1.39 g/cm3, Grazelli abration resistance 4.05 mm3/kgm and flexing resistance at 150 kcs did not break. However, the physical properties of the compound was able to meet the SNI 12-0778-1989 class C except the abration resistance.