Common faults of solid wall pipe extrusion line

In a solid wall pipe extrusion line, several common faults can occur during the manufacturing process. These faults can affect the quality of the produced pipes and may require corrective actions to ensure smooth production. Some of the common faults are as follows:

1. Melt Fracture: Melt fracture occurs as a series of surface distortions or irregularities on the extruded pipe's surface. It is caused by inconsistent melt flow, high shear rates, or improper die design. Melt fracture can lead to surface imperfections and reduced mechanical properties of the pipe.

2. Die Swell: Die swell refers to the expansion of the molten polymer as it exits the die. If not properly managed, it can result in dimensional inaccuracies and deviations from the desired pipe diameter.

3. Sagging or Necking: Sagging or necking is the undesirable deformation of the pipe during the cooling and sizing process. It may occur due to inadequate cooling or improper control of the haul-off speed.

4. Ovality: Ovality is the deviation from a circular cross-section of the extruded pipe. It can occur if the cooling process is not uniform or if there are issues with the sizing tools and haul-off unit.

5. Surface Defects: Surface defects can include scratches, grooves, or other marks on the outer or inner surface of the pipe. These defects may arise due to issues with the calibration or cooling process.

6. Thickness Variation: Inconsistent wall thickness along the length of the pipe can lead to structural weaknesses and potential failure points. This can be caused by uneven flow distribution or issues with the die.

7. Overheating or Burning: Overheating or burning of the polymer can occur if the extruder temperature is too high or if there are issues with the temperature control system.

8. Contamination: Contamination of the raw material or foreign particles in the extrusion process can result in defects on the pipe's surface or compromise its properties.

9. Weld Line: Weld lines occur when two flow fronts meet during the extrusion process, resulting in a weak point in the pipe. This can happen if the melt flow is not properly managed or if the material is cooled too quickly.

To avoid these faults, it is essential to maintain proper process parameters, use high-quality raw materials, and regularly inspect and maintain the extrusion line equipment. Regular monitoring and adjustment of the extrusion process can help ensure the production of high-quality solid wall pipes.