5.Operating instructions of cable extrusion line：
1. Check the plastic used for extrusion molding. The raw materials shall meet the required drying requirements. If necessary, further drying shall be carried out, and the raw materials shall be screened 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 air circuits are smooth and leak free, the electrical system is normal, the heating system, temperature control and various instruments are reliable; oil and lubricate the lubricating parts of various equipment. If any fault is found, remove it in time.
3. Head and set. According to the variety and size of the product, select the head specification. The heads shall be assembled together and integrally mounted on the extruder.
Start up process (5 steps)
4. The machine can be started after constant temperature. Before start-up, the head and flange bolts of extruder shall be tightened again to eliminate the difference of thermal expansion between the bolts and the head. The tightening sequence of the head bolts is to tighten diagonally with even force. When tightening the flange nut of the machine head, it is required to tighten all around uniformly, otherwise, the material will run away.
5. Start up, press the "ready to start" button, then connect the "start" button, and then slowly rotate the screw speed adjustment knob, the screw speed starts slowly. Then gradually speed up, while a small amount of feeding.
When feeding, pay close attention to the indication changes of the ammeter and various indicator heads of the main engine. The screw torque shall not exceed the red mark (generally 65% - 75% of the torque table). Before the plastic profile is extruded, no one shall stand in the front of the die to prevent injury accidents caused by bolt breakage or moisture blistering of raw materials.
6. After the plastic is extruded from the die, it is necessary to slowly cool the extrudate and lead it to the traction device and the setting die, and start these devices. Then according to the indication value of the control instrument and the requirements of the extruded products. Adjust each part accordingly to make the whole extrusion operation reach normal state. The twin-screw extruder adopts the metering feeder to feed the material evenly and at the same speed.
7. When the die is evenly discharged and well molded, it can be used to draw the set. The degree of plasticization should be judged by experience. Generally, it can be judged according to the appearance of extruded materials, that is, the surface has luster, no impurities, no foaming, coke and discoloration.
8. In the process of extrusion production, check whether all process parameters are normal regularly 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 measures to solve problems in time.
Parking cleaning (6 steps)
9. Stop feeding, extrude the plastic in the extruder, when the screw is exposed, turn off the power supply of the barrel and head, and stop heating.
10. Turn off the power supply of extruder and auxiliary machine to stop the screw and auxiliary machine.
11. Open the head connecting flange and disassemble the head. Clean all parts of the perforated plate and head. In order to prevent damage to the internal surface of the machine head during cleaning, the residual materials in the machine head shall be cleaned with steel law and steel sheet, and then the plastic adhering to the machine head shall be ground off with sandpaper, polished and coated with oil or silicone oil for rust prevention.
12. Clean the screw and barrel. After the head is removed, restart the main engine, add parking materials (or broken materials) and clean the screw and barrel. At this time, the screw selects low speed (SR / min or so) to reduce wear.
13. after the parking material is completely extruded into powder, compressed air can be used to blow out the residual granular material and powder from the feeding port and the exhaust port repeatedly until there is no residual material in the barrel, reduce the screw speed to zero, stop the extruder, and close the main power supply and the main valve of cold water.
14. The safety items to be paid attention to during extrusion include: electric, thermal, mechanical rotation, loading and unloading of heavy parts, etc. The extrusion locomotive room must be equipped with lifting equipment, assembly and disassembly of heavy parts such as head and screw to ensure safety in production.