METHOD AND APPARATUS FOR MAINTENANCE OF KNEADING EXTRUDER

PURPOSE: To estimate the generation of abnormality to prevent the same by executing the corresponding treatment for keeping stable operation over a long period of time by monitoring the operation state of a kneading extruder at any time. CONSTITUTION: The plastic material supplied from a hopper 3 is kneaded and melted while successively fed to a supply part, a kneading part and a weighing part by the screw 2 rotated in a cylinder 1 and passed through the screen 7a of a screen changer 7 while increased in extrusion pressure by a gear pump 6 to be extruded from an extrusion die. The sonic waves respectively detected by the first and second sonic wave detection means 8, 9 provided to the outer peripheral surface of the cylinder 1 corresponding to the upstream and downstream ends of the kneading part are analyzed by a waveform analyser 10 to monitor the fluctuations of the kneading state in the kneading part at any time and the correction treatment for dealing with the fluctuations is rapidly executed with high accuracy.