Injection Molding
2 views
Insufficient rigidity of general-purpose polyethylene injection molded products
Problem Phenomenon
The product has a large deformation when stressed, and the rigidity modulus is lower than the design requirement.
Insufficient rigidity causes the product to deform too much during use, affecting function and safety, and is especially critical in structural parts.
Cause Analysis
（1）General-purpose polyethylene has low crystallinity and insufficient rigidity modulus
（2）The product wall thickness is too thin or the reinforcing rib design is unreasonable
（3）The mold temperature is low, and the cooling is too fast and the crystallization is insufficient
（4）The barrel temperature is high, and the material is degraded and the molecular weight is reduced
（5）The material grade is improperly selected or the reinforcing material is insufficiently added
Solution
（1）Raise the mold temperature to the higher value within the range of 30-80°C to increase the crystallinity
（2）Optimize the product design, increase the wall thickness or reinforcing ribs, and increase the section moment of inertia
（3）Control the barrel temperature at a reasonable value within the range of 160-260°C
（4）Extend the cooling time to ensure sufficient crystallization
（5）Select high-rigidity grades or add nucleating agents, and use reinforcing materials if necessary
Key Takeaway
Insufficient rigidity is caused by low crystallinity or unreasonable structural design, and needs to be solved from both process parameters and product design.
Was this helpful?
0 people found this helpful
Thank you for your feedback!