The Wear of High Molecular Weight Polyethylene—Part II: The Effects of Reciprocating Motion, Orientation in the Polyethylene, and a Preliminary Study of the Wear of Polyethylene Against Itself

The wear of ultra-high molecular weight polyethylene against relatively smooth, dry stainless steel takes place by the same basic wear mechanisms whether unidirectional or reciprocating motion is used, but reciprocating motion produces slightly less wear overall. The effect of molecular orientation in the polyethylene has been studied and it has been shown that orientation perpendicular to the wearing surface is undesirable, whereas orientation parallel to the wear surface is mildly beneficial. The wear of polyethylene against itself is relatively severe and is largely determined by the temperatures reached by the rubbing surfaces.