Development of inner tube using a blend of natural rubber and chlorobutyl rubber

Abstract

In order to develop the properties of tubes manufactured by Sri Lanka Tyre Corporation (SLTC), attempts have been made to improve the physical properties specially with respect to cir permeability mentioned in Chapter I -without changing the possessing parameters In this project attempts have been made to improve the properties of tubes manufactured by srilanka tyre Corporation, by modifying the present formulation used. Modification was one in two stages. In first stage, Natural Rubber(NR) was re placed by the blends of Chlorobutyl (ClIIR) and NTR, while keeping accelerator system constant. Blends of C1IIR and NTR were selected as 100/0 (KR/C1IIR), 90/10, 80/20, 70/30, 60/40. After examining physical properties of above vulcanisates as men ioned in Chapter I and cost factor, the blend of 80/20(N3/C1IIR) was selected to carry out the second part. In the second part, accelar at or system was changed from semi efficient vulcanizing to efficient vulcanizing while keeping the blend of SR/C1IIR 80/20 constant. In this study, it was observed that system (I) and (£) (-Table 13) give better test results than other systems investigated. It appears that 80/20(NR/C1IIR) blend is suitable for tube manufacturing either using accelar at or system (1) or (2) (-Table7).