Extrusion & Post
9 views
Dimensional Fluctuation of Polypropylene Extruded Products
Problem Phenomenon
The outer diameter, wall thickness, or width of the extruded product fluctuates periodically or randomly in the longitudinal direction.
Dimensional fluctuation affects the fitting precision and use performance of the product, and is common in pipe and profile extrusion.
Cause Analysis
(1) The screw speed is unstable, and the discharge amount fluctuates
(2) The haul-off speed is unstable and does not match the extrusion speed
(3) The barrel temperature fluctuates greatly, and the melt viscosity changes
(4) The raw material feeding is uneven, and the feeding fluctuates
(5) The cooling water temperature or flow fluctuates
Solution
(1) Check the extruder drive system and stabilize the screw speed
(2) Check the speed regulation system of the haul-off machine to ensure stable haul-off speed
(3) Stabilize the barrel temperature, with fluctuation controlled within ±3°C (range 200-280°C)
(4) Check the feeding of the hopper to ensure continuous and uniform feeding
(5) Stabilize the cooling water temperature and flow, and add a constant temperature device when necessary
Key Takeaway
Dimensional fluctuation is caused by unstable extrusion or haul-off, and all process parameters need to be systematically stabilized.
Was this helpful?
0 people found this helpful
Thank you for your feedback!