Analysis of PVC Screw Breakage: Normal Wear and Abnormal Breakage

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”.

Analysis of PVC Screw Breakage: Normal Wear and Abnormal Breakage

Normal Screw Breakage:

Screws are consumable parts in the extrusion process, and their lifespan varies depending on the amount of calcium powder added to the product. Generally, screws have the following lifespans:

Up to 100 parts calcium: 1-2 years

100-200 parts calcium: about 1 year

200-300 parts calcium: 6-8 months

Over 300 parts calcium: 3 months

The choice of calcium powder is also important; light calcium significantly extends the screw's lifespan compared to heavy calcium. Severe wear leading to breakage is considered normal.

Abnormal Screw Breakage:

I. Screw breakage due to distribution box bearing damage:

Cause: Bearing aging or inherent quality issues.

Solution: Replace the bearing.

Prevention: Regularly inspect the distribution box, paying special attention to any abnormal sounds.

II. Screw breakage due to insufficient heating temperature:

Cause: Issues with the electrical circuit or damaged heating ring.

Solution: Check the circuit or replace the heating ring.

Prevention: Carefully check the temperature of each zone before starting the machine, and regularly monitor temperatures during production.

III. Screw breakage due to material interruption during production:

Cause: Material bridging in the hopper or failure to add material promptly.

Solution: Install a stirring device in the hopper.

Prevention: Regularly check the raw material in the spring feeder or screw feeder hopper, and install an alarm in the discharge hopper.

IV. Screw breakage due to formulation errors:

Cause: Errors by the mixing personnel.

Solution: Strictly follow the formulation sheet when mixing materials.

Prevention: Regularly check the main engine current, and carefully observe the machine's operating status when changing formulations.

V. Screw breakage due to foreign objects in raw materials:

Cause: Foreign objects in the raw materials causing the screw to jam.

Solution: Place a strong magnet at the discharge port.

Prevention: Regularly clean impurities from the surface of the strong magnet.

Conclusion:

Most screw breakages are caused by these reasons. By preventing these issues, the likelihood of screw breakage can be significantly reduced.

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.