Maintenance of Single Screw Extruder


Ningbo Fangli Technology Co., Ltd. is a mechanical equipment manufacturer with nearly 30 years’ experiences of plastic pipe extrusion equipment, new environmental protection and new materials equipment. Since its establishment Fangli has been developed based on user’s demands. Through continuous improvement, independent R&D on the core technology and digestion & absorption of advanced technology and other means, we have developed PVC pipe extrusion line, PP-R pipe extrusion line, PE water supply / gas pipe extrusion line, which was recommended by the Chinese Ministry of Construction to replace imported products. We have gained the title of “First-class Brand in Zhejiang Province”.


The maintenance of the extruder is divided into routine maintenance and regular maintenance: routine maintenance is a regular routine work, usually completed during start-up. The key is to clean the machine, lubricate the moving parts, fasten the loose threaded parts, and timely check and adjust the motor, control instrument, working parts and pipelines. The daily maintenance shall be completed by the extruder operator when the extruder is turned on and off every day, which generally does not take up the working hours of the equipment.

Regular maintenance is generally carried out after the extruder has been running continuously for 2500-5000h. The machine needs to be disassembled to inspect, measure and identify the wear of main parts, replace the parts that have reached the specified wear limit, and repair the damaged parts.


Daily maintenance and precautions:

1. It is not allowed to run empty to avoid scratching the barrel. During no-load test run, the speed shall not be higher than 3rpm.

2. Metal or other sundries shall be strictly prevented from falling into the hopper to avoid damaging the screw and barrel. To prevent iron impurities from entering the barrel, magnetic absorption parts or magnetic racks can be installed at the feeding points of the barrel. When feeding, check whether there is a magnetic frame in the bucket. If there is no magnetic frame, it must be put into it immediately. Frequently check and clean the metal objects attached to the magnetic frame. In order to prevent sundries from falling in, the materials must be screened in advance.

3. The equipment shall always be kept clean and well lubricated. Wiping and lubrication shall be done well at ordinary times. Pay attention to the clean production environment. Do not let garbage and impurities enter the material to block the filter plate, which will affect the product output and quality and increase the head resistance.

4. Before starting up each time, check whether there is material leakage and air leakage at the connection of the extruder, especially at the connection of the upper and lower stages and at the tail of the lower stage, that is, at the connection of the extruder and the transmission box. If there is any leakage, replace the sealing or locking screws immediately.

5. In case of abnormal noise during the operation of the extruder, stop the extruder immediately for inspection or repair.

6. Regularly calibrate the temperature control instrument, and check its correctness of adjustment and control sensitivity.

7. The maintenance of the reducer of the extruder is the same as that of the general standard reducer. It is mainly to check the wear and failure of gears, bearings, etc., whether the cooling water is unblocked, and the lubrication of each rotating part. The reducer shall use the lubricating oil specified in the machine manual, and the oil shall be added according to the specified oil level. The oil is too little, the lubrication is poor, and the service life of the parts is reduced; Too much oil, high heat, high energy consumption, and easy deterioration of oil will also cause lubrication failure, resulting in damage to parts. The sealing gasket shall be replaced at the leaking part of the reducer in time to ensure the amount of lubricating oil.

8. The inner wall of the cooling water pipe attached to the extruder is easy to scale, and the outer surface of the Teflon pipe or steel wire pipe is easy to rust. Careful inspection shall be carried out during maintenance. Too much scale will block the pipeline and prevent it from cooling. Serious corrosion will lead to water leakage Therefore, descaling and anti-corrosion cooling measures must be taken during maintenance. Regularly check the sealing and water leakage of various pipe filters and joints, and protect the cooling pipes.

9. Timely check the locking of all fasteners of the machine, such as the fastening screws of the heating ring, the terminal blocks, and the external shield elements of the machine.

10. In case of power supply interruption, all potentiometers must be reset to zero (that is, the upper and lower main machine speed must be reset to zero and the drive and heating must be stopped. After the voltage is normal, the machine must be reheated to the set value and can only be started after heat preservation 11. For the DC motor driving the screw to rotate, it is necessary to focus on the inspection of brush wear and contact, and it is also necessary to frequently measure whether the insulation resistance of the motor is above the specified value. In addition, check whether the connecting wire and other parts are rusty, and take protective measures.

12. When the extruder needs to be out of service for a long time, anti rust grease shall be applied to the working surfaces of the screw, the die and the head. Small screws shall be suspended in the air or placed in special wooden boxes, and leveled with wooden blocks to avoid screw deformation or damage.


If you need more information, Ningbo Fangli Technology Co., Ltd. welcomes you to contact for a detailed inquiry, we will provide you with professional technical guidance or equipment procurement suggestions.

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