Screw injection system is the most widely used an injection system, mainly by the plasticizing unit (screw, barrel, nozzle), hopper, transmission device, injection oil cylinder, a whole mobile oil cylinder injection, etc. Plasticizing unit and transmission device is installed in the injection seat, seat provided by the injection of a whole mobile oil cylinder injection thrust, can guide rail along the injection seat or guide pillar reciprocating motion, make the nozzle to evacuate and stick close mold master water crossings. At the same time, in order to replace the screw and the cleaning cartridge, the rotary structure is provided in the center of the base, so that the injection seat is rotated in a certain Angle around its rotating shaft.

Screw injection system working principle is: the material from the hopper to the feeding mouth into the cylinder, rely on the rotation of the screw conveying material continuously forward, in the external heater and turn the screw cylinder under the action of shear friction material is plasticizing rising gradually falls. The plasticized melt is transported to the front of the screw. With the rotation of the screw, the screw head of the melt volume, the more the greater the pressure, under the impetus of the melt pressure, screw rotation and retreat, when screw the front melt injection to the expected amount, metering device hit stroke switch, make the screw stop running, ready for injection. When injection, injection pressure oil into the oil cylinder, push the oil cylinder piston driven screw at a certain speed and pressure, the screw head front melt into the mold cavity, then for the holding and fill material, after the start of a work cycle.