Conductive wire covering - with elastomer or plastomer by microwave energy in extruder head for vulcanisation or crosslinking

摘要

Strands of electrically conductive material are coated with an elastomer or a plastomer in an extruder with a screw and a nozzle head. Directly in or ahead of the latter, microwave energy is injected into the strand over a very short distance and caused to travel in the strand in the direction of motion. This produces the heat for the vulcanisation of an elastomer or the crosslinking of a plastomer. The action of the microwaves continues downstream of the nozzle which is specially advantageous when a second coating is to be applied through a second extruder. The effect is a very uniform vulcanisation or crosslinking.