Common Faults and Solutions for WPC Decking Extrusion Line
Comprehensive Guide to Common Faults and Technical Solutions for WPC Decking Extrusion Line Operations
During the manufacturing and operation of WPC decking extrusion lines, a variety of common malfunctions and technical challenges are likely to arise throughout the production process. These issues not only lead to a decline in overall production efficiency but can also substantially compromise the final product quality and dimensional consistency.
The following section outlines several typical types of malfunctions that operators may encounter, along with practical and effective solutions to address each specific problem:
1. Host cannot extrude material / High current / Large torque
Table of Problem Causes and Solutions
|
Cause of the problem |
terms of settlement |
|
High moisture content in flour |
The flour must be dried (moisture content <3%) |
|
Lack of lubrication |
Appropriate adjustment of internal and external lubricants |
|
Low temperature and poor plasticization |
Increase the barrel/mold head temperature by 5–15°C |
|
mold blockage |
First reduce the host machine speed and avoid forced operation; check if the vacuum is normal and clean the die head filter. |
2. Material feeding bridge, material interruption, and unstable output
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
Moisture absorption and clumping of powder |
Vibrator added to hopper Moderately reduce the proportion of fine powder to improve fluidity |
|
The hopper is too steep and lacks vibration. |
Vibrator added to hopper |
3. Bubbles/Needle holes on the product surface
Problem Cause and Solution Table
|
cause |
terms of settlement |
|
High moisture content in flour |
Raw materials must be dried |
|
vacuum exhaust difference |
Enhanced vacuum exhaust (-0.08 to-0.09 MPa) |
|
overheating decomposition |
Reduce the front-end temperature to prevent premature decomposition |
4. Rough surface, dull appearance, with exposed wood powder
Problem Cause and Solution Table
|
cause |
terms of settlement |
|
Insufficient plasticization |
Slightly increase the host rotation speed to enhance shear plasticization |
|
low mold temperature |
Increase the die temperature by 5–15°C |
|
Insufficient lubrication |
Add internal lubricant appropriately |
5. Surface spots, oil stains, and delamination
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
excessive external lubricant |
Reduce outer sliding, paraffin, PE wax |
|
insufficient compatibilizer |
Add compatibilizer (maleic anhydride grafting); improve mixing uniformity |
6. Uneven thickness of the plate, with one side thicker than the other
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
uneven intermolar space |
Adjust the die head bolt to fine-tune the lip-to-mouth clearance
|
|
Temperature variation around the mold |
Inspect the heating ring of the mold to ensure uniform temperature distribution between the left and right sides. Check if the mold is centered |
7. Deformation, warping, bending, and dimensional instability
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
inconsistent cooling |
Reduce the cooling water temperature and increase the flow rate |
|
Vacuum deficiency |
Increase the vacuum level to ensure the sheet adheres tightly to the forming die. |
|
stamping die wear |
Check for waterway blockage; align the traction center with the mold and setting mold |
8. Material discharge with waves, serpentine patterns, and shaking
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
Traction instability |
Check the traction pressure and rubber roller; ensure synchronization between the traction system and the main unit. |
|
extrusion pressure fluctuation |
Stable feeding, stable die head pressure |
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
hyperpyrexia |
reduce the heat |
|
screw / die carbon deposit |
Clean and replace the die head, screw, and filter screen |
|
Long-term uncleaned machine |
Thoroughly replace the material and clean the machine |
10. Cracking, transverse cracking, longitudinal cracking
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
Cooling too fast |
Slow down the cooling process and avoid sudden cooling. |
|
high internal stress |
reduce traction speed |
|
The recipe is too brittle. |
Increase the toughness component and reduce the high filler content |
11. Traction Slippage, Inability to Pull
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
Excessive lateral spread |
reduce external lubricant |
|
rubber roller wear |
Replace / grind the traction roller |
|
Insufficient pressure |
Increase the pressure of the traction cylinder |
12. Cutting burrs and trimming edges
Problem Cause and Solution Table
|
Cause of the problem |
terms of settlement |
|
Blunt blade |
Sharpening / Changing the blade |
|
The food hasn't cooled down yet. |
extended cooling |
|
Speed mismatch |
Adjust the fly-by-synch speed |