Process Parameter Optimization for Hot Embossing Uniformly Textured UHMWPE Surfaces for Orthopedic Bearings

To improve wear properties and reduce friction in orthopedic bearings, UHMWPE surface texturing is a proposed approach to retain fluid, reduce stress in the polymer and promote lubrication in the joint. The objective of this study was to establish a preliminary procedure to texture UHMWPE specimens using a custom die in a hot embosser. Four parameters were varied in subsequent stages: hold pressure, chamber temperature, hold duration and specimen cooling. Each stage was based upon the successful results of the previous stage. A dimple diameter of 96% of the desired diameter was achieved. These parameters will be used to commence a formal procedure to optimize the process using a formal DOE method.