Mainly used for rubber heat refining, tableting, breaking, plasticizing and mixing. It consists of rollers, roller bearings, roller distance adjustment device, emergency braking device, frame, machine base, transmission device and heating and cooling system. The working principle of the open rubber mixing machine is: raw rubber or rubber material is pulled into the nip by friction between two rollers that rotate opposite to each other at different speeds, and the plasticity is increased by strong shearing and extrusion. This two-roll open mixer has been in production since 1826. Its structure is relatively simple, and it is still widely used in modern times.
Mainly used for plasticizing and mixing of rubber. It has one more mixing chamber than an open mixer (Figure 1). After the raw rubber and compounding agent are loaded into the mixing chamber from the feeding hopper, the material door is closed, the top bolt of the pressing device is pressed down, and the two rotors in the mixing chamber rotate in opposite directions at different or the same speed. The loaded rubber is continuously stirred, rolled and kneaded between the rotors, between the rotors and the mixing chamber, resulting in oxidative chain scission and increased plasticity. At the same time, the rubber material is dispersed and uniformly mixed due to shearing action, so as to achieve the purpose of rubber mixing. Since the invention of the oval-rotor closed-type rubber mixer in 1916, the closed-type rubber mixer has developed rapidly in the rubber industry. Later, other types of closed-type rubber mixers with rotors appeared. The mixing cycle of modern closed rubber mixing machine is 2.5 to 3 minutes, and the maximum capacity of the mixing chamber is 650 liters.
Rubber machinery is used to extrude treads, inner tubes, hoses and various rubber profiles, as well as covering cable and wire products. The most common is the screw extruder. Its working principle is: the rubber material is stirred, mixed, plasticized and compressed in the barrel with the help of the rotation of the extrusion screw, and then moves to the direction of the machine head, and finally extrudes a certain shape of product from the mouth. According to the needs of the product, multiple machines can be used for compound extrusion of various rubber materials. Screw extruders are divided into two types: hot feeding and cold feeding. Hot feed extruders typically feed strands that have been preheated through an open mixer. The rubber fed by the cold feed extruder does not undergo thermal refining, so the thermal refining equipment can be omitted.