Heating method of plastic extrusion die, plastic extrusion die and extruder

摘要

PROBLEM TO BE SOLVED: To enhance a heating efficiency around a nozzle. SOLUTION: A solenoid coil C is arranged around a nozzle P of a die 10. Around the coil C, for example, a magnetic permeable sheet F made of iron is arranged. Consequently, a magnetic flux generated by the coil C induces an eddy current around the nozzle P and thereby, the surroundings of the nozzle P are heated to prevent the die from being clogged. On the other hand, the magnetic flux generated by the coil C penetrates the magnetic permeable sheet F having a low magnetic resistance on the opposite side to the nozzle P, hence there is no substantial energy consumption. As a result, the heating efficiency around the nozzle P is increased.