METHOD FOR CONTROLLING DIE SWELL OF VISCOELASTIC MATERIAL IN SCREW EXTRUDER WITH PIN

摘要

PROBLEM TO BE SOLVED: To efficiently extrude a viscoelastic material under high precision die swell by setting a feedback system between the viscosity and temperature of the material detected by sensor pins attached at the end of a screw and the insertion rate of numbers of work pins. SOLUTION: Forefront pins 5a-5f closest to the end of a screw on the extrusion head 7 side are sensor pins for detecting the properties of a viscoelastic material. Hydraulic mechanisms 9-1-9-8 carry out operation to make work pins 4-1-4-8 freely movable on the inside and the outside of the radial direction of a screw 2 on the basis of the feedback command of the viscosity and temperature of the material which are detected independently by the sensor pins 5a-5f. The operation individually controls the insertion depth of the work pins 4-1-4-8 into the material by the feedback signal while the extrusion work of the material continues. The insertion depth is based on the distance between the inside wall of the cylinder and the bottom of the screw and expressed by an insertion rate.