Loading patent…
AssigneeHowmedica Osteonics Corp.
InventorsAiguo Wang, John H. Dumbleton, Aaron Essner, Shi-Shen Yau
Estimating the term…
A method of producing an improved polyethylene, especially an ultra-high molecular weight polyethylene utilizes a sequential irradiation and annealing process to form a highly cross-linked polyethylene material. The use of sequential irradiation followed by sequential annealing after each irradiation allows each dose of irradiation in the series of doses to be relatively low while achieving a total dose which is sufficiently high to cross-link the material. The process may either be applied to a preformed material such as a rod or bar or sheet made from polyethylene resin or may be applied to a finished polyethylene part.
A method for increasing the wear resistance of an ultra high molecular weight polyethylene (UHMWPE) medical implant comprising:
A method of making an ultrahigh molecular weight polyethylene (UHMWPE) medical implant comprising heating a preformed UHMWPE to a temperature between about 110° C. and about 135° C. but lower than the melting point, thereafter irradiating the preformed UHMWPE at least three times to a total dose of 5 to 10 Mrad maintaining the temperature for about 8 hours after each irradiation followed by cooling to room temperature after each heating and thereafter forming the medical implant.
A method for increasing the wear resistance of an ultrahigh molecular weight polyethylene (UHMWPE) medical implant comprising:
A method of making an ultrahigh molecular weight polyethylene (UHMWPE) medical implant comprising irradiating the UHMWPE at least three times to a total dose of 5 to 10 MRad and heating for at least about 8 hours at a temperature from 110° C. to 135° C. but lower than the melting point of the UHMWPE after each irradiation followed by cooling to room temperature after each heating.
A method of making an ultrahigh molecular weight polyethylene (UHMWPE) medical implant comprising heating a preformed UHMWPE to a temperature between about 110° C. and about 135° C. but lower than the melting point, thereafter irradiating the preformed UHMWPE at least three times to a total dose of 5 to 10 Mrad maintaining the temperature for about 8 hours after the irradiation followed by cooling to room temperature after heating and thereafter forming the medical implant.
Dependencies are inferred from the claim text.