Flow Behavior of 'EPDM' Rubber during Dry Compression

摘要

In the recent time rubber has emerged as a very useful and suitable material for wider varieties of engineering and other applications which includes but not limited to domestic, sports and many more. It possesses large elasticity compared to metals, has greater damping capability, high internal friction and can accumulate energy to a greater extent compared to steel or other metals. During the deformation of rubber material, particularly by compressive force, internal damping of the material leads to energy dissipation. This is the cause of hysteretic friction of rubber. Friction of rubber has practical importance. At the same time it has many disadvantages too. Use of rubber as engineering material is not new. However, in the recent time its application is gaining renewed importance as well as interest due to several engineering researches and property enhancement too. It is, however, needless to be mentioned that prediction of exact behavior of any viscoelastic material like rubber is very difficult. In the present work compression tests have been carried out to determine the flow characteristics of EPDM rubber of different hardness. Flat mild steel platens have been used to apply axysymetric compressive load on the specimen under dry working condition. The flow behavior like load - elongation curves, true stress - true strain curves and specific energy requirements have been computed from the experimental data. Statical hysteresis and the loss factors have also been obtained. Experimental results reveal that the hardness of EPDM rubber has significant effect on the flow behavior. Thus, it can be stated that the flow behavior can be governed by controlling the carbon black (CB) concentration in EPDM rubber as the hardness depends on it. It is proposed to extend the experiments with the application of different kind of lubricants.