The Effect of Technological Parameters on the Quality of UHMWPE Products

Abstract

We can encounter products made from UHMWPE in many different areas of utilization. This material is used in plastic bearings, ball-and-socket joints, heavy-duty plastic cog-wheels and joint implants. The UHMWPE is a very particular polymer, the special characteristics of which can be attributed to its molecular structure. The ulra-high molecular weight has an effect on wear-resistance, creep-resistance and hardness. These are the parameters demanded by the highly specialized utilization. On the other hand, this molecular stucture also has disadvantages next to the many advantages. Its greatest disadvantage is that it’s difficult to process. The UHMWPE is a thermoplastic, but because of the long molecular chains its injection molding is impossible. In the course of the present research work we will compare the mechanical and quality properties of products made with lathe machining (RAM extrusion) and direct compression molding. We will examine the impact of the changes of the manufacturing and technological parameters. We will be placing a special emphasis on the surface quality because the quality and life-span of the abovementioned products (bearings, ball-and-socket joints, artficial joints) largely depends on this parameter. Besides this we will examine the changes of hardness and the stability of size. In view of these results we will try to determine what would be the best manufacturing technology that could ensure the maximum performance and life-span of these products. [1,3,6] We are focusing by having the results, to optimizing the manufacturing.