Sequentially cross-linked polyethylene for medical implants

[Subject] Offer a polymer material equipped with the outstanding oxidation resistance, mechanical strength, and wear and abrasion resistance, for example, the method of manufacturing UHMWPE. [Solution means] In order that this method may make polymer construct a bridge, it uses at least two separate heat treatment of the same number which glares and continues, reduces a free radical, and manufactures elevated bridge polymer material. Although each exposure dose is the amount of low comparatively, a sum total dose is quantity sufficient for bridge construction of material. This process may be applied to preforming material, or may be applied to completion polyethylene parts. In the case of application to completed parts, irradiation and annealing are performed without contacting oxygen with 1% or more of oxygen concentration. Annealing is performed, before being machined into an implant and put to oxygen, when applying to a preforming thing. [Selection figure] Nothing