Twelve quality problems and solutions of PE pipes Ⅱ

8. Outer surface waterline

Reason: The local water eye of the sizing sleeve is blocked, resulting in excessive water volume in individual water holes.

Solution: clean the sizing sleeve.

9. The inner wall groove (mostly in the wall thickness pipe)

Reason: The wall thickness is too thick, the melt is difficult to cool, and flow occurs.

Solution: Try the central cooling system to reduce the temperature of the mouth and core.

10. Uneven thickness of pipe wall

Reasons: 1) The bolts of the mouth touch or core touch are loose, and the adjustment of the mouth touch gap is not appropriate. 2) The temperature of the mouth or core is uneven, resulting in inconsistent material flow. 3) The sizing sleeve and the mouth are not aligned, the spiral shunt shuttle or the screen is blocked.

Solution: 1) Tighten the bolts or adjust the gap between the mouth and touch. 2) Check the heating ring and temperature sensor. 3) Adjust the sizing sleeve and the mouth touch to fold the shuttle or screen.

11. Low elongation at break

Reasons: 1. The raw materials are not well-formed; 2. The orientation increases and the cleanliness increases.

Solution: 1. Adjust the process temperature to strengthen the plasticizing effect 2. Increase the distance between the mouth touch and the sizing sleeve.

12. Large ovality:

Reason: Gravity

Solution: increase the correction device

PE pipe manufacturers must establish strict raw material supplier evaluation procedures, select appropriate raw materials and conduct appropriate processing according to the testing conditions of raw materials. The production of high-quality polyethylene pressure pipes is highly dependent on the comprehensive output capacity of the equipment. Pipe manufacturers must fully investigate and demonstrate when selecting equipment to choose equipment with higher cost performance. Pipe manufacturers should establish strict operating procedures and process procedures and strengthen process and control efforts in order to achieve the purpose of not only controlling the quality of pipes but also reasonably reducing production costs. The process setting of pressure pipes and the solution of quality problems in the production process require a lot of production experience, which requires manufacturers to accumulate a large amount of original data, analyze and summarize, and guide production to achieve steady improvement in product quality.