EFFECT OF DEGASSING PRESSURE CASTING ON HARDNESS, DENSITY AND TEAR STRENGTH OF SILICONE RUBBER RTV 497 AND RTV 00A WITH 30% TALC REINFORCEMENT

Shoes are one of the human needs that are useful for protecting the feet. In addition, the use of shoes is currently adapted to the activities carried out such as formal events, sports to lifestyle enhancement. When humans stand upright, the two hind feet bear the burden of 60% of the body weight. When walking, the weight of one foot in the heel area can reach 70% of the body weight. So we need a shoe insole to overcome these problems. This study aims to improve the mechanical properties and reduce the value of porosity that arises due to air bubbles resulting from the reaction of hardener with silicone rubber, so it is necessary to have a method to reduce the value of por osity in the insole material which is made from silicone rubber and 30% talc using the degassing pressure casting method. The pressure variations applied during the molding process are 200 KPa (2.07 bar), 275 KPa (2.76 bar), and 345 KPa (3.45bar). Composit e specimens were tested for tear strength, density, and hardness to determine hardness, density, tear strength. The highest tear strength value was at a pressure of 200 KPa (2.07 bar) and the lowest was at 345 KPa (3.45 bar). The highest strain is at a pressure of 200 KPa (2.07 bar) and the smallest is at 345 KPa (3.45.bar), while the highest stress is at a pressure of 345 KPa (3.45Bar) and the smallest at 200 KPa (2.07 bar) for RTV.497.