Method of preparing insulated electrical conductors

Claim 1

A METHOD FOR CONTINUOUSLY EXTRUDING A THERMOPLASTIC COMPOSITION ABOUT AND ONTO AN ELECTRICAL CONDUCTOR WHICH COMPRISES CONTINUOUSLY FEEDING A COMPOSITION COMPRISING POLYETHYLENE RESIN AND P,P''-OXYBIS(BENZENE SULFONYL HYDRAZIDE) TO A SCREW EXTRUDE CYLINDER, SAID P,P''-OXYBIS(BENZENE SULFONYL HYDRAZIDE) BEING PRESENT IN AN AMOUNT OF ABOUT 1% BY WEIGHT OF SAID COMPOSITION, WORKING AND FEEDING SAID COMPOSITION ALONG SAID CYLINDER WHILE HEATING SAID CYLINDER TO A TEMPERATURE SUFFICIENT OT CAUSE SUBSTANTIALLY COMPLETE DECOMPOSITION OF SAID HYDRAZIDE, RESTRICTING THE FLOW OF SAID COMPOSITION TO DEVELOP A HIGH BACK PRESSURE IN SAID CYLINDER THEREBY COMPRESSING AND SUBSTANTIALLY PREVENTING THE GAS FORMED BY SAID DECOMPOSITION FORM EXPANDING WITHIN THE COMPRISING IN SAID CYLINDER, DIRECTING SAID COMPOSITION AS IT PASSES FROM SAID CYLINDER THROUGH A FORMING SECTION COMPRISING A DIE AND A HOLLOW GUIDER PIN, SAID GAS WITHIN SAID COMPOSITION NOT SUBSTANTIALLY EXPANDING THEREIN WHILE SAID COMPOSITION IS PASSING THROUGH SAID FORMING SECTION, PASSING AN ELECTRICAL CONDUCTOR WHICH HAS BEEN HEATED TO A TEMPERATURE OF AT LEAST ABOUT 100*C. THROUGH SAID HOLLOW GUIDER PIN EXTRUDING SAID COMPOSITION ABOUT SAID ELECTRICAL CONDUCTOR, SAID COMPRESSED GAS WITHIN SAID COMPOSITION BEING FREE TO COMMMENCE GAS WITHIN SAID COMPOSITION AS SAID COMPOSITION EMERGES FROM THE FORMING SECTION AND IS SLOWLY COOLED, THE SAID COMPRESSED GASES EXPANDING SAID POLYETHYLENE COMPOSITION TO THE EXTENT OF THE APPROXIMATE VALUE DETERMINED BY THE EQUATION: