The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 21, 2001
Filed:
Sep. 27, 1999
Silvio Schaffner, Basadingen, CH;
Sulzer Orthopaedie AG, Baar, CH;
Abstract
UHMW polyethylene for implants which are intended for a sterilization by means of &ggr; rays or electron beams are doped with vitamin E during the manufacture, which binds off the free radicals faster than the oxygen from the surroundings after the irradiation and thus prevents an oxidation and aging of the implants. A starting material in powder form is wetted at its surface with a liquid which has a suitable amount of vitamin E in order to achieve a concentration K of vitamin E of 0.01%<K<1% on the polyethylene particles. After the evaporation of the liquid the PE powder is compressed to blocks or processed to rods at temperatures around 180° C.-240° C. and pressures from 2-10 MPa.