Patent ID: 8563623

Claim:
A preformed material for subsequent production of a wear resistant medical implant comprising a cross-linked consolidated Ultra High Molecular Weight Polyethylene (UHMWPE) produced by a method comprising the steps of: (a) irradiating consolidated UHMWPE to cross-link polyethylene molecules and to achieve an absorbed radiation dose and generate radiation-induced heat, wherein the UHMWPE is pre-heated to a temperature below the melting temperature of the UHMWPE; (b) following step (a), subsequently irradiating the consolidated cross-linked UHMWPE to achieve a subsequent absorbed radiation dose and generate further radiation-induced heat, wherein the temperature of the consolidated cross-linked UHMWPE is above room temperature and below the melting temperature of the consolidated cross-linked UHMWPE; (c) repeating step (b) until a total absorbed radiation dose of 7.5 to about 100 MRad is obtained; and (d) allowing the cross-linked consolidated UHMWPE to cool.