1、 Preparation before start-up
1. Plastic used for extrusion molding. Raw materials shall meet the required drying requirements, and further drying is required if necessary. And the raw materials are sieved to remove agglomerates and mechanical impurities.
2. Check whether the water, electricity and gas systems of the equipment are normal, ensure that the water and gas circuits are unblocked and leak free, whether the electrical system is normal, and whether the heating system, temperature control and various instruments work reliably; Low speed test run of the auxiliary machine with no load and observe whether the equipment operates normally; Start the vacuum pump of the setting table and observe whether it works normally; Lubricate the lubricating parts of various equipment. If any fault is found, it shall be removed in time.
3. Mounting head and setting sleeve. According to the variety and size of the product, select the head specification. Assemble the machine head in the following order.
2、 Drive
1. The machine can be started after the constant temperature is reached. Before the start-up, the head and extruder flange bolts should be tightened again to eliminate the difference between the thermal expansion of the bolts and the head. The head bolts should be tightened diagonally and evenly. When tightening the flange nuts of the machine head, it is required that the tightness of the four sides should be consistent, otherwise the material will run away.
2. To start up, press the ready to start button, then connect the start button, and then slowly rotate the screw speed adjustment knob to start the screw speed slowly. Then gradually speed up and add a small amount of materials. During feeding, pay close attention to the indication changes of the host ammeter and various indicator heads. The twin-screw extruder uses a metering feeder to feed evenly and at the same speed.
3. When the discharge of the die is uniform and the plastic is good, the tractor can be used to set the sleeve. The plasticizing degree shall be judged by experience. Generally, it can be judged according to the appearance of the extruded material, that is, the surface is glossy, free of impurities, foaming, coke and discoloration. When the extruded material is squeezed by hand to a certain extent, there is no burr or crack, and there is a certain degree of elasticity, it indicates that the material is plasticized well. If the plasticization is poor, the screw speed, barrel and head temperature can be adjusted properly until the requirements are met.
4. In the process of extrusion production, regularly check whether various process parameters are normal according to the process requirements, and fill in the process record sheet. Check the quality of profile products according to the quality inspection standards, and take timely measures to solve problems.
3、 Parking
1. Stop feeding and extrude the plastic in the extruder. When the screw is exposed, turn off the power supply of the barrel and head and stop heating.
2. Turn off the power supply of the aluminum profile extruder of the motor housing and the auxiliary machine to stop the screw and the auxiliary machine.
3. Open the connecting flange of the machine head and disassemble the machine head. Clean the perforated plate and various parts of the machine head. In order to prevent damage to the inner surface of the machine head during cleaning, the residual materials in the machine head shall be cleaned with steel laws and steel sheets, and then the plastic adhered to the machine head shall be ground off with sandpaper, polished, and coated with engine oil or silicone oil for rust prevention.
4. Clean the screw and barrel. After the head is removed, restart the main machine, add shutdown materials (or broken materials), and clean the screw and barrel. At this time, the screw is selected at low speed (about Sr / min) to reduce wear. After the stopped material is milled into powder and completely extruded, compressed air can be used to repeatedly blow out the residual particles and powder from the feeding port and the exhaust port until there is no residual material in the barrel. After that, reduce the screw speed to zero, stop the extruder, and turn off the main power supply and the main cold water valve.
5. The safety items that should be paid attention to during extrusion of aluminum profile extruder for motor housing include: electrical, thermal, mechanical rotation and loading and unloading of heavy parts. The extrusion locomotive room must be equipped with lifting equipment to assemble and disassemble heavy parts such as machine head and screw to ensure safe production.
