Ultra-high molecular weight polyethylene (UHMWPE) is a polyethylene with a molecular weight ranging from one million to seven million. UHMWPE is often used for constructing sliding parts such as artificial knees, hip joints, and gears owing to its self-lubrication, wear resistance, biocompatibility, and light weight structure. High accuracy and smooth surfaces are required for UHMWPE parts. Cutting operations of UHMWPE are particularly suitable for small numbers of products and to realize high shape accuracy. This paper describes some surface properties due to ball end mill operations of inclined surfaces. Some inclined workpieces are fixed by jigs and various cutting conditions are analyzed. Two tool path patterns, namely contour line and raster line (scanning line), are also evaluated for various cutting conditions by surface observations and surface roughness measurement.

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