Abstract:
The invention relates to a process for producing an (ultra) high molecular weight polyethylene (HMWPE) article comprising:—incorporating into the HMWPE resin a Hindered Amine Light Stabilizer (HALS) and—cross-link the (U)HMWPE during or after molding the (U)HMWPE resin. In particular the invention relates to a process comprising the following steps: a) incorporating into (U)HMWPE resin a Hindered Amine Light Stabilizer (HALS) according to one of the following general formulas or combinations hereof: wherein R1 up to and including R5 are herein independent substituents; for example containing hydrogen, ether, ester, amine, amide, alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl and/or aryl groups, which substituents may in turn contain functional groups, for example alcohols, ketones, anhydrides, imines, siloxanes, ethers, carboxyl groups, aldehydes, esters, amides, imides, amines, nitriles, ethers, urethanes and any combination thereof; b) molding the (U)HMWPE resin comprising the HALS, resulting in an article; c) cross-linking and sterilizing the article via gamma radiation or electron beam radiation; d) optionally, if step b results in a stock shape, machining the stock shape into an article; wherein step c and step d can be performed in either order.
Abstract:
The invention relates to a process for the production of an article, wherein—ethylene is polymerized with a polyene and optionally another comonomer, resulting in a polymer with a MFI (21.6) between 0.05 dg/min and 100 dg/min,—melt processing the polymer into an article,—optionally crosslinking the polymer during or after melt processing the polymer and—optionally sterilizing the polymer article by high energy irradiation.
Abstract:
The invention relates to a process for the production of an ultra-high molecular weight polyethylene ((U)HMWPE) article comprising: —copolymerizing ethylene with a linear, branched or cyclic polyene having 3 to 100 carbon atoms, resulting in a copolymer of ethylene and polyene ((U)HMWPE-P), using such a content of polyene that the number of polyene branches in (U)HMWPE-P is 0.01 to 15 on the average per 1000 carbon atoms; —cross-link the (U)HMWPE-P during or after molding the (U)HMWPE-P.
Abstract:
The invention relates to a process for producing an (ultra) high molecular weight polyethylene (HMWPE) article comprising:—incorporating into the HMWPE resin a Hindered Amine Light Stabilizer (HALS) and—cross-link the (U)HMWPE during or after molding the (U)HMWPE resin. In particular the invention relates to a process comprising the following steps: a) incorporating into (U)HMWPE resin a Hindered Amine Light Stabilizer (HALS) according to one of the following general formulas or combinations hereof: wherein R1 up to and including R5 are herein independent substituents; for example containing hydrogen, ether, ester, amine, amide, alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl and/or aryl groups, which substituents may in turn contain functional groups, for example alcohols, ketones, anhydrides, imines, siloxanes, ethers, carboxyl groups, aldehydes, esters, amides, imides, amines, nitriles, ethers, urethanes and any combination thereof; b) molding the (U)HMWPE resin comprising the HALS, resulting in an article; c) cross-linking and sterilizing the article via gamma radiation or electron beam radiation; d) optionally, if step b results in a stock shape, machining the stock shape into an article; wherein step c and step d can be performed in either order.