First, the main body of the plastic extruder is an extruder, which consists of an extrusion system, a transmission system, and a heating and cooling system.
1. Extrusion system The extrusion system consists of a screw, a barrel, a hopper, a machine head, and a mold. The plastic is plasticized into a uniform melt through an extrusion system, and is continuously continuous by the screw under the pressure established in the process. Extruder head.
2. Transmission system The function of the transmission system is to drive the screw. The torque and speed required by the supply screw during the extrusion process are usually composed of a motor, a reducer and a bearing.
3. Heating and Cooling Unit Heating and cooling are necessary for the plastic extrusion process.
Second, the auxiliary equipment of the auxiliary equipment plastic extrusion unit mainly includes the pay-off device, the straightening device, the preheating device, the cooling device, the traction device, the metering device, the spark testing machine, and the wire take-up device. The use of the extrusion unit is different for its optional auxiliary equipment. For example, there are also cutters, blowers, printing devices, and the like.
Third, the control system Plastic extruder control system includes heating system, cooling system and process parameter measurement system, mainly consists of electrical appliances, instruments and actuators (ie control panel and console). Its main function is: control and adjust the drag motor of the main and auxiliary machines, output the speed and power according to the process requirements, and enable the main and auxiliary machines to coordinate work; detect and adjust the temperature, pressure and flow of the plastic in the extruder; Control or automatic control of the entire unit. The electrical control of the extrusion unit is roughly divided into two parts: transmission control and temperature control, which realizes the control of the extrusion process including temperature, pressure, screw revolution, screw cooling, barrel cooling, product cooling and outer diameter, and traction speed. The neatly arranged cable and the constant tension take-up control from the empty to the full plate on the take-up reel. The control of the screw speed is the core of the whole set of equipment. The adjustment and stability of the screw speed is one of the important process requirements of the main drive. The screw speed directly determines the amount of glue and the extrusion speed. The normal production always wants to achieve the highest speed and achieve high production. When the extruder requires the screw speed from starting to the required working speed, the available speed range is large. . Moreover, the stability of the rotational speed is required to be high, because the fluctuation of the rotational speed will cause the fluctuation of the extrusion amount and affect the extrusion quality, so that the change of the outer diameter of the cable will occur if the traction line speed does not change. Similarly, if the linear velocity of the traction device fluctuates greatly, the outer diameter of the cable will change. The screw and traction line speed can be reflected by the corresponding instrument on the console, and should be closely observed during extrusion to ensure high quality and high yield.