PURPOSE: To eliminate unevenness in temperature, kneading, and mixture through quiet substitution of a specified quantity of resin, by a method wherein a multi-screw thread is formed in a screw of a kneading mixing part for resin, pins are radially projected from a barrel inner surface into a plurality of grooves being formed in its periphery in the manner that its bottom is positioned in the same level as that of the trough diameter of screw.
CONSTITUTION: An extruder 11 consists of a feed part 13a for preheating a thermoplastic resin material, charged through a hopper 14, by a heater 15 for conveyance, a compressing part 13b for fusing and kneading the material, and a weighing part 13c for further kneading it to make uniform the mixture and adjusting a supply amount to an adapter 16. A kneading and mixing device 17 is mounted from the terminal of the compressing part 13b to the weighing part 13c, and grooves 19, whose bottom is positioned in the same level as that of a surface of a root diameter of screw, are formed in a 3 or more threaded screw 18 in a peripheral direction at given intervals. A plurality of pins 20 are projected into the grooves 19 through an inner wall surface of a barrel 12, and are positioned so that they keep a taper gap between a gate 21 and them during the passage of it through the gate. Thus, resin in grooves 22W25 is flowed such that divided flow 22aW25a are branched from the main streams 22AW25A, and only a given quantity is flowed through a given gap into grooves 22W25, whereby only a given quantity of resin is substituted.
IGUCHI KATSUHIRO
NOZAWA KENJI
Next Patent: SCREW FOR UNIAXIAL EXTRUSION MOLDING MACHINE