Injection Molding
5 views
Insufficient fiber retention length in the product
Problem Phenomenon
Inspection finds that the fiber length in the product is <0.5mm, far below the design target
Cause Analysis
The shear in the screw mixing section is too strong, cutting the glass fibers; the shear rate at the runner/gate of the injection system is too high; the material is repeatedly cut through multiple thermal histories
Solution
Use a low-shear screw design (L/D=18-20, compression ratio 1.5-1.8); optimize runner and gate dimensions with smooth transitions to reduce shear rate; reduce screw speed
Key Takeaway
Fiber retention length is the primary factor determining the reinforcement effect
Was this helpful?
0 people found this helpful
Thank you for your feedback!