Plastic extruder is also classified as one of the varieties of plastic machinery. According to the material flow direction of the die head and the angle between the center line of the screw, the extruder can divide the die head into right angle die and oblique angle die.
The screw extruder relies on the pressure and shear force generated by the rotation of the screw, which can make the material can be fully plasticized and uniformly mixed, and then formed through the die.
Overview
The shell of the machine head is generally fixed on the fuselage with bolts. The mold inside the machine head contains a core holder, and then is fixed to the inlet port of the machine head with a nut. The inside of the core holder is also installed The mold core, and the center of the mold core and the mold core seat have holes, which are used to pass the core wire. According to the different types of pressurization methods, the extrusion process can be divided into continuous extrusion and intermittent extrusion. The equipment used in the former is a screw extruder, and the equipment in the latter is a plunger extruder. Here, screw extruders can be roughly classified into single-screw extruders and multi-screw extruders based on the number of screws.
The operating mechanism of the screw extruder is to rely on the pressure and shear force generated by the rotation of the screw, which can make the material can be fully plasticized and uniformly mixed, and then molded through the die; so sometimes one extruder can be used to complete the process. A series of processes such as mixing, plasticizing and molding, and then proceed to successive production. In addition, the operating mechanism of the plunger extruder mainly relies on the plunger pressure to first extrude the material that has been previously plasticized from the die to achieve the molding effect. After the material in the material barrel is extruded, the plunger will return. Compared with adding a new round of plasticized material, the next round of operation is carried out. This production process is attributed to non-continuous production, and the material cannot be adequately processed. Mixing and mixing. In addition, this production needs to be pre-plasticized. Therefore, this method is generally not used in practice. It can only be applied to plastics with extremely poor fluidity or very high viscosity, such as nitrocellulose plastics. Kind of plastic products molding processing.
Plastic extruders can be basically classified into twin-screw extruders, single-screw extruders, and rare multi-screw extruders and screw-less extruders.