Extrusion & Post
2 views
Die marks/lines on low density polyethylene extruded products
Problem Phenomenon
Continuous lines or marks appear on the extrudate surface along the extrusion direction at fixed positions.
Die marks affect product appearance, especially obvious in transparent products and films.
Cause Analysis
(1) Scratches or damage on the die inner wall
(2) Impurities or carbide accumulation inside the die
(3) Unreasonable die flow channel design, stagnation zones
(4) Uneven die joint
(5) Breaker plate or filter screen damaged, impurities passing through
Solution
(1) Disassemble the mold to check the die inner wall; grind and polish to repair scratches
(2) Clean impurities and carbides inside the die, use copper tools to avoid damage
(3) Optimize die flow channel design, eliminate stagnation dead corners
(4) Grind the die joint flat, ensure no steps
(5) Replace breaker plate and filter screens, replace regularly to prevent damage
Key Takeaway
Die marks are caused by die inner wall damage or impurities; the die condition needs regular cleaning and inspection.
Was this helpful?
0 people found this helpful
Thank you for your feedback!