STP1445: The Flow Ratio Effect on Oriented, Crosslinked Ultra-High Molecular Weight Polyethylene (UHMWPE)

    King, RS
    Principal Scientist, Scientist, and Principal Scientist, DePuy Orthopedics, Warsaw, IN

    Young, SK
    Principal Scientist, Scientist, and Principal Scientist, DePuy Orthopedics, Warsaw, IN

    Greer, KW
    Principal Scientist, Scientist, and Principal Scientist, DePuy Orthopedics, Warsaw, IN

    Pages: 9    Published: Jan 2004


    Abstract

    The compression molding process is known to produce UHMWPE components of improved oxidation resistance [1] and quality surface finish. Induction of molecular orientation in non-crosslinked UHMWPE was demonstrated by using a slot drawing process [2]. The objective of this study was to assess the effect of flow ratio on wear and mechanical properties of crosslinked UHMPWE. Pre-irradiated GUR 1020 preforms, corresponding to flow ratios from 1.06 to 1.40, were evaluated in this study. Molecular orientation was shown by Thermal Mechanical Analysis and crossed polarizer microphotographs. Tensile (Type V), double notched Izod and pin on disk wear data were generated. The degree of molecular orientation was correlated with the flow ratio and was reflected by the enhancement of the mechanical properties. Pin on disk wear data show that there was no significant difference in wear resistance between oriented, crosslinked UHMWPE and its machined counterpart.

    Keywords:

    ultra-high molecular weight polyethylene, crosslinking, compression molding, molecular orientation, orthopedic medical devices


    Paper ID: STP11930S

    Committee/Subcommittee: F04.02

    DOI: 10.1520/STP11930S


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