Extruder belongs to the category of plastic machinery. The extruder can be divided into right-angled and oblique-angled heads according to the material flow direction of the head and the included angle of the screw centerline. The screw extruder relies on the pressure and shear force generated by the rotation of the screw, so that the material can be fully plasticized and uniformly mixed, and formed through a die. Plastic extruders can be basically classified into twin-screw extruders, single-screw extruders and rare multi-screw extruders and screw-free extruders.
Plastic extruder is divided into twin screw extruder and single screw extruder Difference between the two extruders: Single-screw machine and double-screw machine: one is a screw, the other is two screws. Both are driven by a motor. The power varies with the screw. The extruder can be divided into single screw, twin screw and multi-screw extruder according to the number of screws. Today, single screw extruder is the most widely used and suitable for extrusion processing of general materials. The twin-screw extruder has less heat generated by friction, more uniform shearing of the material, larger screw conveying capacity, more stable extrusion capacity, longer material stay in the barrel, and uniform mixing. The twin screw extruder has good feeding characteristics, is suitable for powder processing, and has better mixing, venting, reaction and self-cleaning functions than the single screw extruder. It is characterized by processing plastics and blends with poor thermal stability. Shows its superiority when the material. In recent years, foreign twin-screw extruders have been greatly developed. Various forms of twin-screw extruders have been serialized and commercialized, and there are many manufacturers, which are roughly classified as follows: ⑴ According to the relative positions of the two axes, there are parallel and tapered points; ⑵ According to the two-screw meshing program, there are two types of meshing and non-meshing; (3) According to the direction of rotation of the two screws, there are points of the same direction and different directions, and there are points of inward and outward in the different directions; ⑷ According to the rotation speed of the screw, there are high speed and low speed; ⑸According to the structure of the screw and barrel, there are integral and combined points. On the basis of twin-screw extruders, in order to more easily process blends with poor thermal stability, some manufacturers have developed multi-screw extruders such as planetary extruders.