"Asia Rubber Expo & India Rubber Technology Exhibition 2020" is jointly sponsored by Aakar Exhibition Company and Zhonglian Rubber Co., Ltd. The exhibition will be held at the Chennai Trade Center...Read More
The function of the rubber extruder is to use heating, pressure and shearing methods to transform solid plastic into a uniform melt and send the melt to the next process. The production of the melt involves the process of mixing additives such as color masterbatches, blending resins, and pulverizing. The finished melt must be uniform in concentration and temperature. The pressure must be large enough to squeeze out the viscous polymer.
The rubber extruder completes all the above processes through a barrel with a screw and a spiral channel. The plastic pellets enter the barrel through a hopper, and then are conveyed to the other end of the barrel through the screw. In order to have sufficient pressure, the depth of the thread on the screw decreases as the interval to the hopper increases. External heating and internal heat generated by friction between the plastic and the screw cause the plastic to soften and melt. Different polymers and different applications often have different design requirements for extruders. Many options involve discharge ports, multiple feeding ports, special mixing devices along the screw, cooling and heating of the melt, or no external heat source (exhaust heat extruder), the gap between the screw and the barrel changes relatively Size, and the number of screws, etc. For example, a twin-screw extruder can mix the melt more fully than a single-screw extruder. Tandem extrusion is a melt extruded by a rubber extruder, which is used as a raw material to supply a second rubber extruder, usually used to produce extruded polyethylene foam.
The rubber extruder is equipped with a filter screen, which can block impurities on the filter screen. To avoid downtime, the filter screen should be able to be replaced automatically. This is particularly important when processing resins with impurities, such as recycled materials. The screw of the extruder is divided into feeding section, plasticizing section and melting section. The temperature is based on the process parameters of the plastic particles, and the model is divided into 20, 36, 52, 65, 75, 95, 120, 135 according to the screw diameter. After the plastic particles are heated, the original state is changed by the movement of the screw, and there are many types, depending on the specific application. The capacity of the frequency conversion is proportional to the diameter of the screw, and then adjusted according to the different raw materials.