Abstract: In a twin extruder wherein an underwater cutting apparatus 12 is connected, via a gear pump 9, to an discharge port 8 of a cylinder 1 which houses therein twin screws both ends of which are supported, both sides of both screws 2, 3 are material conveying sections 5a, 5b having flights of small lead, the downstream sides of the respective material conveying sections 5a, 5b are kneading sections 6a, 6b having flights of large lead, both kneading sections 6a, 6b are connected about the center of the screws 2, 3, and the cylinder 1 positioned at the center of the screws 2, 3 is provided with the discharge port 8.

Abstract: An object of the present invention is to provide a kneading and extruding machine which includes a screw type two-shaft kneader and a gear pump in which the degree of kneading melted resin material can be made uniform at the discharging port of the screw type two-shaft kneader. In the kneading and extruding machine of the present invention, the height of scraping flights or inverse flights of the screw in the discharging section of the screw type two-shaft kneader is determined to be an average of the inner diameter of the cylinder and the bottom diameter of the groove of the screw at the most.

Abstract: An object of the present invention is to provide a kneading and extruding machine which includes a screw type two-shaft kneader and a gear pump in which the degree of kneading melted resin material can be made uniform at the discharging port of the screw type two-shaft kneader. In the kneading and extruding machine of the present invention, the height of scraping flights or inverse flights of the screw in the discharging section of the screw type two-shaft kneader is determined to be an average of the inner diameter of the cylinder and the bottom diameter of the groove of the screw at the most.

Abstract: A screen pack replacing apparatus in accordance with the present invention is arranged such that a single slide bar having at least two or four screen packs is slidably provided in a main body disposed on a cylinder. As the slide bar is moved, the screen packs can be replaced, and the overall configuration can be made compact and the filtering area can be made large.

Abstract: An extruder in which the joint between the downstream, forward end portion of a cylinder and a gear pump is always kept tight, so that molten resin material is prevented from leaking out. As the main discharge port of a diverter valve is prevented from shifting from the inhalation port of the gear pump at the joint therebetween, the flow passage at the joint is always smooth without a spot where the molten resin material collects. The quality of resin products thus becomes stable.