Abstract
The current work represents a practical study with the aim of get the best design for hard rubber recipes by controlling materials that increase this property. Rubber recipes were prepared consisting of several materials, such as natural rubber, zinc oxide, and stearic acid, in addition to the accelerator and vulcanizing agent sulfur, which were added in multiple proportions 10, 20, 30 part per hundred rubber (pphr). Also, recipes were prepared for the same previous ingredients with an increased percentage Zinc oxide to 150 pphr to demonstrate the effect of this material on the hardness property. Some laboratory tests were conducted to investigate the mechanical behavior of these recipes, such as hardness, tension, and Rebound (resilience) test. The recipe with sulfur 30 pphr gave an acceptable indication in hardness and tensile test with value 98 IRHD and 35 MPa respectively. Same recipe in rebound test not the best but was acceptable result, while the recipe with sulfur 10 pphr was the best in resilience test results (25%). Other rubber recipes with zinc oxide 150 pphr gave acceptable result specially in recipe with sulfur at 30 pphr. Two form of composite plate covered with hard rubber recipe may result, external bonding process of individual plates and vulcanized plate with hard rubber recipe in thermal press. The final hard rubber recipes may be use in other different applications as an alternative material to withstands against various stresses with specific properties.
