Extruder is used to extrude tread, inner tube, rubber tube, and various rubber strips, as well as to cover cable and wire products. A common type is a screw extruder. Its working principle is: the rubber is stirred, mixed, plasticized, and pressed in the barrel by the rotation of the extrusion screw, and then moved towards the machine head, finally extruding a certain shape of product from the mouth. According to the needs of the product, multiple machines can be used for composite extrusion of various rubber compounds. Screw extruders are divided into hot feed and cold feed. Hot feed extruders typically feed strips preheated by an open mixer. The rubber fed by the cold feed extruder does not undergo heat refining, thereby eliminating the need for heat refining equipment.

The closed rubber mixer is mainly used for rubber molding and mixing. It has one more internal mixing chamber than an open rubber mixer. After the raw rubber and compounding agent are loaded into the mixing chamber from the feeding hopper, the material door is closed, and the top bolt of the pressing device is pressed down. The two rotors in the mixing chamber rotate in opposite directions at different or the same speed. The loaded rubber is subjected to continuous stirring, folding, and intense kneading between the rotors, as well as between the rotors and the internal mixing chamber, resulting in oxidative chain breakage and increased plasticity. At the same time, the rubber material is dispersed and uniformly mixed due to shearing action, thereby achieving the purpose of rubber mixing.