How to Maintain the Twin Screw Extruder Barrel?

Twin screw extruder barrels are mainly used for filling, blending, modifying, enhancing, chlorinating, processing polypropylene and highly absorbent resins, degradable pellets, polyamide condensation, polyurethane polymerization reactions, granulation of carbon powder and magnetic powder, preparation of insulation materials, sheathing materials, low-smoke halogen-free flame-retardant PVC cable materials and various silane-crosslinked materials for cables. Small models are mainly used for scientific research and teaching.

The material barrel and screws of the parallel twin screw pelletizer are designed according to the principle of building blocks and can be combined as needed. It uses electric heating and water cooling to automatically control the temperature of the machine barrel and has a force-feeding device, vacuum exhaust, and non-stop screen changer. The twin screw extruder barrel uses variable frequency speed regulation, AC motor drive or DC speed regulation, and DC motor drive. The reduction and twin screw transmission are in the same housing, with a compact size. It uses a safety coupling with shear pins to protect the screw and transmission from damage due to overload.

Maintenance knowledge of the twin screw extruder barrel

After the twin screw extruder lab scale has been in use for a period of time, a comprehensive inspection should be carried out to check the tightness of all screws.
In case of power interruption during production, when the power supply is restored, the temperature of each section of the barrel must be heated to the specified temperature and kept warm for a period of time before starting the extruder.
After the extruder has been used for 500 hours, there will be iron filings or other impurities ground off from the gears in the reduction gearbox, so the gears should be cleaned and the lubricating oil in the gearbox should be replaced.
If the pointer of the instrument turns excessively, check whether the contact of the thermocouple or other wiring is good.

Daily maintenance of the twin screw extruder barrel

No foreign objects such as metal, sand, and gravel are allowed in the material, and it is strictly forbidden to enter the hopper and extruder.
When opening the barrel cover or exhaust cover, be careful not to let foreign objects fall into the main machine.
The twi screw extruder barrel needs sufficient preheating and temperature rise time, and the manual disc should be operated lightly before driving. Generally, the temperature should be kept constant for 2 hours after reaching the set temperature of the process.
The screw can only be started at low speed, and the idle time should not exceed 3 minutes.
After the new machine is run-in, all gearbox oils should be replaced, and the lubricating oil should be replaced once every 3000 operating hours. The oil quality should be tested during necessary maintenance, and it should be replaced when necessary.
Check the wear of the twin screw extruder elements every year, including barrel and screw, gearbox, bearings, and oil seals.
If the main motor is a DC motor, check the motor carbon brush every month and record it. Replace it in a timely manner if necessary.
When the machine is parked for a long time, it should be rust-proof and dust-proof.
The daily inspection content includes the lubrication and oil level of each lubrication part, the temperature rise and noise of each rotating part bearing, and the vibration of the unit; the current and voltage display of the motor; the temperature and pressure display of the lubricating oil and cooling water and the leakage of their pipelines.

Disassembly and maintenance of the twin screw extruder barrel and screw

Confirm that the material in the barrel is completely melted, remove the head, and extrude the screw.
Remove the material and carbon deposits on the surface of the screw. Be careful not to use a steel bar to knock during the cleaning process. Use tools such as copper plates, copper rods, and copper wire brushes.