Using an aluminum profile extrusion machine involves a series of steps like installation, adjustment, test runs, operation, maintenance, and repairs. Although it may seem complicated, you really just need to follow the instructions. However, as an operator, you must be familiar with the specific structure of the extrusion machine you're working with, so you can properly control the extrusion process and operate the machine correctly. There are many types of extrusion machines, and while the key operating points differ, they also share some similarities. Today, let's go over the operation steps and key points of using an aluminum profile extrusion machine in detail.
一. Preparations before driving
1. For plastics used in extrusion molding, the raw materials should meet the required drying conditions. If necessary, further drying should be done. Also, sieve the materials to remove clumps and mechanical impurities.
2. Check whether the water, electricity, and gas systems in the equipment are functioning properly, make sure the water and gas lines are unobstructed and leak-free, and check if the electrical system is normal. Ensure the heating system, temperature control, and various instruments are working reliably. Run the auxiliary machines at low speed without load to see if they operate normally. Start the vacuum pump on the sizing device and check if it works properly. Lubricate all sliding parts of the equipment. If any faults are found, fix them in time.
3. Install the machine head and sizing sleeve. Choose the machine head specifications according to the type and size of the product. Install the machine head in the following order.
二. Starting the Machine
1. You can start the machine once the temperature has stabilized. Before starting, you should retighten the bolts on the machine head and extruder flange to compensate for thermal expansion differences. When tightening the head bolts, follow a diagonal pattern and apply force evenly. When tightening the flange nuts, make sure the tension is uniform all around; otherwise, material may leak.
2. To start, first press the 'Prepare to Start' button, then the 'Start' button. Slowly turn the screw speed adjustment knob to start the screw at a low speed. Gradually increase the speed while adding a small amount of material. Pay close attention to the main motor ammeter and other indicator readings, and adjust the feed as needed. For a twin-screw extruder, use a metering feeder to add material evenly and at a consistent speed.
3. Once the material from the die is uniform and the plasticization is good, you can proceed with pulling and shaping. Plastication is judged by experience, usually based on the material's appearance-look for a glossy surface, no impurities, no foaming, burning, or discoloration. When pressing the extrudate by hand, it should grind to a fine level without burrs or cracks and have some elasticity, which indicates proper plasticization. If plasticization isn't good, adjust the screw speed, barrel, and head temperature until it meets the requirements.
4. During extrusion production, regularly check all process parameters according to the production requirements and record them in the process log. Inspect the profile products based on quality standards, and promptly address any issues that arise.
三. Stopping the Machine
1. Stop feeding materials. Once the plastic in the extruder is fully pushed out and the screw is exposed, turn off the power to the barrel and the head, and stop heating.
2. Turn off the power to the aluminum profile extruder and auxiliary machines to stop the screw and auxiliary equipment.
3. Open the flange connecting the machine head and remove the head. Clean the die plate and all components of the head. To avoid damaging the inner surface of the head, use steel brushes or steel sheets to clean the remaining material, then use sandpaper to remove any plastic stuck inside, polish it, and apply machine oil or silicone oil to prevent rust.
4. For screw and barrel cleaning, after removing the head, restart the main machine, add stop-feed material (or crushed material), and clean the screw and barrel. At this time, the screw should run at low speed (around sr/min) to reduce wear. Once the stop-feed material is fully ground into powder and extruded, compressed air can be blown repeatedly from the feed and exhaust ports to remove any remaining pellets and powder. After confirming there is no leftover material in the barrel, reduce the screw speed to zero, stop the extruder, and turn off the main power and the main cold water valve.
5. Safety items to note when extruding aluminum profiles include electricity, heat, moving mechanical parts, and handling heavy components. The extrusion workshop must have lifting equipment for installing and dismantling heavy parts like the machine head and screw to ensure safe production.
