Abstract: The pelletizing die for a synthetic resin extruding machine has a sintered hard tip which is shaped such that the outlet side is small as compared to the inlet side. A sintered hard tip pressing plate is formed to surround the sintered hard tip, and the sintered hard tip and sintered hard tip pressing plate are fixedly adhered to the die body by solder.

Abstract: A pipe die for an underwater pelletizer is provided in which a nozzle plate is provided on the surface of a pipe die, the nozzle plate having a hole coaxially with and of the same diameter as a pipe of the pipe die. The nozzle plate is made of a material of the same quality as the die body and is provided with a hardened layer at its cutter side surface. Replacement and repair of the nozzle plate is improved by connecting the same to said die body by bonding the whole junction plane therebetween.

Abstract: When rubber is melted and decomposed in a screw extruder, a rubber melt can be produced without using a heavy oil with minimized evolution of gas by controlling the extruder cylinder temperature in the decomposing section of the screw within the range of 400.degree.-500.degree. C. and cooling the melt in the discharging section of the screw to a temperature of not more than 250.degree. C. The screw extruder suited for practising this method comprises a screw having a feeding section, a compressing section, a decomposing section and a discharging section which are arranged in that order from the inlet side, and a cylinder assembly consisting of a heating cylinder and a cooling cylinder arranged in that order from the inlet side, said feeding, compressing and decomposing sections of the screw being located corresponding to said heating cylinder, and said discharging section of the screw being located corresponding to said cooling cylinder.

Abstract: A biaxial vent extruder for processing of slurry-like waste fluids or radioactive waste fluids having a hopper cylinder having a solidifying substance port and a solidified substance port. A plurality of vent cylinders each having a vent port are provided with a plunger type scraper. An extruding cylinder having a single opening for a main screw is connected to the assembled vent cylinders. The main screw extends to the upstream end of the extruding cylinder and a sub-screw extends to the extruding cylinder. The screws each having a full flight engaging the other and a set of rings are mounted on the screws near the respective vent port inlets. The screws are rotated in different directions and inwardly with respect to the vent ports. Rotors may be mounted on the screws to break down solid particles.