METHOD AND DEVICE FOR HEATING AND/OR CROSS-LINKING OF POLYMERS Russian patent published in 2001 - IPC

FIELD: method of quick heating of polymers, polymer mixes at manufacture of extruded pipes of polyethylene. SUBSTANCE: polymeric materials are heated, exposed to infra-red radiation, from which wavelengths corresponding to the wavelengths of peaks of absorption of polymeric material are removed. The device for heating has at least one source of infra-red radiation for exposure of polymeric material to infra-red radiation corresponding to the wavelengths of peaks of absorption of polymeric material are removed. At repair of pipe-lines a lining pipe is introduced in the pipe-line, the lining pipe length corresponds to the length of the pipe-line to be repaired, which is made of one or several layers of polyethylene with cross links and has an outside diameter smaller than the inside diameter of the pipe-line. For expansion of the lining pipe to the walls of the pipe-line it is heated by infra-red radiation within the mentioned range. In manufacture of the lining pipe for repair of the pipe-line it is made for expansion to the walls of the pipe-line by heating by infra-red radiation within the mentioned range. The invention provides for a method for manufacture of oriented pipes of polymeric material such as polylefin or polyvinyl chloride in which the pipes are heated to the orientation temperature with the aid of infra-red radiation, in which the wavelengths corresponding to the peaks of absorption of these layers with respect to infra-red radiation are removed, then the pipes are expanded and cooled down. EFFECT: quick, contactless and uniform heating of polymeric material, as well as high-rate cross-linking of it with a good finish. 48 cl