Operation of Wire and Cable Extruders: Extruder Operating Procedures:

I. Preparations Before Powering On the Equipment

1. Plastics used for extrusion molding: The raw materials must meet the required drying specifications; if necessary, further drying should be performed, and the material should be screened to remove agglomerates, lumps, and mechanical impurities.

2. Inspect the water, electricity, and gas systems of the equipment to ensure they are functioning properly; verify that water and gas lines are unobstructed and leak-free, and that the electrical system is operating normally. Confirm that the heating system, temperature control, and all instruments are working reliably. Conduct a no‑load, low‑speed trial run of the auxiliary machinery to check for proper operation. Start the vacuum pump on the shaping table and verify that it is operating correctly; if any malfunctions are detected, address them promptly.

3. Die head and sizing sleeve. Select the appropriate die head specifications based on the product type and dimensions.

II. Power On

1. After reaching the set temperature, the machine may be started. Prior to startup, re‑tighten the head and extruder flange bolts to compensate for differential thermal expansion between the bolts and the head. Tighten the head bolts in a diagonal sequence, applying even torque. When tightening the head flange nuts, ensure uniform tension around all four sides; otherwise, material leakage may occur.

2. Power on the machine, select and press the “Ready to Start” button, then press the “Start” button. Next, slowly turn the screw speed adjustment knob to initiate the screw at a low speed, gradually increasing the speed while adding material in small quantities. Make the necessary adjustments to all components to bring the extrusion process into normal operating condition, and replenish the material as required.

3. When the die discharge is uniform and the plasticization is good, proceed with drawing the extrudate into the sizing sleeve. Assessing the degree of plasticization relies on experience: manually extrude the material until it reaches a certain fineness without burrs or cracks, exhibiting adequate elasticity—this indicates proper plasticization. If plasticization is inadequate, appropriately adjust the screw speed, barrel temperature, and die head temperature until the desired results are achieved.

4. During the extrusion process, various process parameters shall be checked regularly in accordance with process requirements to ensure they are within normal ranges, and the process record form shall be completed. The quality of extruded profiles shall be inspected according to the quality inspection standards, and any issues identified shall be addressed promptly.

III. Shutdown

1. Stop feeding material, extrude all the plastic remaining in the extruder until the screw is exposed, then turn off the barrel and die power supplies and cease heating.

2. Turn off the extruder and auxiliary equipment power supplies to stop the screw and auxiliary machines from running.

3. Open the die head connection flange and remove the die head. Clean the porous plate and all components of the die head. To prevent damage to the inner surfaces of the die head during cleaning, use steel rods and steel blades to remove residual material, then sand off any plastic adhering inside with sandpaper, polish the surface, and apply machine oil or silicone oil to prevent rust.

4. Cleaning of the screw and barrel. After the machine is stopped and the material has been completely extruded into a powdery form, use compressed air to repeatedly blow out any residual pellets and powder through the feed port and vent ports until no material remains in the barrel. Then reduce the screw speed to zero, stop the extruder, and shut off the main power supply and the main cold-water valve.

5. Safety precautions during extrusion include electrical hazards, heat, rotating machinery, and the handling of heavy components. The extrusion workshop is equipped with lifting devices for loading and unloading the die head, screw, and other heavy parts, thereby ensuring safe production.