METHOD FOR HEATING PLASTIC EXTRUSION DIE, PLASTIC EXTRUSION DIE, AND EXTRUSION MACHINE

摘要

PROBLEM TO BE SOLVED: To raise heat resistance allowable temperature of a coil and inhibit the adverse effect of an electromagnetic radiation from a feeder cable to the surroundings and further, enable meeting the requirements of various kinds of dies of different structures. SOLUTION: A coil (C) obtained by winding a wire with a thickness of 1.5 mm or over around a core into a multi-layer or many times, is used and an alternating current is supplied form a variable frequency inverter (H) which changes the frequency of the alternating current. Consequently, this plastic extrusion die can deal with a resin whose molten resin temperature is high, as the allowable temperature of the coil (C) is high. When the frequency of an alternating current is lowered by the variable frequency inverter (H), it is possible to inhibit the adverse effect of an electromagnetic radiation upon the surroundings. The extrusion dies of different structures can be dealt with by changing the frequency of the alternating current by means of the inverter (H).