Common problems and solutions in the production of PVC pipe production equipment


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”.



PVC pipe production equipment is prone to the following problems due to improper operation or other reasons in the production process of plastic extruder. The solutions are as follows:


Surface discoloration

1. The temperature of the barrel or head is too high to decompose the materials, which requires cooling.

2. The material is not stable enough and decomposes. It is necessary to check whether the PVC resin or stabilizer causes insufficient stability. Replace the resin or stabilizer or increase the number of stabilizer.

3. Failure of temperature instrument control, decomposition caused by over temperature, adjustment and maintenance of instruments.


There are yellowish brown stripes or color spots on the surface of the pipe

1. There are dead corners or depressions in the mold or shunting shuttle, resulting in stagnation of material and paste and local decomposition stripes. When the mold is cleaned, the increased friction with the pipe surface caused by local paste and dead corner of the mold will decompose, and stripes will be formed.

2. Uneven mixing or impurities in materials can cause local decomposition and form surface color spots. Determine the specific causes, improve the mixing process or replace the problematic raw materials.


Dull appearance

1. The die temperature is low. Increasing the die temperature and increasing the amount of ACR can improve the shear. The bright ACR processing aid can significantly improve the surface finish even at low temperature.

2. If the die temperature is too high or the internal surface finish is poor, reduce the temperature and reduce the roughness.


Rough inner wall

1. If the core mold temperature is too low, increase the core temperature or increase the auxiliary agent. The low temperature causes poor plasticization and the inner wall is difficult to rise at the die head.


Blistering on pipe wall

1. The vacuum at the vacuum exhaust hole behind the second section of the barrel is too low or blocked. Check the working condition of the pump and whether the pipeline is blocked (caused by powder pumping).

2. There is decomposition (the head temperature is too high) and the temperature needs to be reduced.


Uneven thickness of pipe wall

1. The temperature of the machine head is uneven and the discharge speed is slow. It is necessary to check the heating ring and the screw for pulsation.

2. If the traction speed is unstable, check and repair the tractor.


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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