Warpage deformation of homopolymer polypropylene injection products (Variant: strengthened measures)

The product shows bending, twisting, or warpage deformation after demolding, flatness out of tolerance, assembly difficult. Deformation usually gradually intensifies within hours after demolding; in severe cases the product is completely unusable, especially common in large flat and thin-wall products. In particular, additional attention is needed on the original basis; this problem is more prominent and requires key attention.

(1) High crystallinity of homopolymer polypropylene; inconsistent shrinkage in each direction, non-uniform shrinkage causes warpage (2) Uneven product wall thickness; thick-wall areas shrink more, thin-wall areas shrink less, producing internal stress (3) Uneven mold temperature; cooling rate differences across cavity parts cause uneven shrinkage (4) Uneven holding pressure distribution; high pressure near the gate, low pressure at the far end, large shrinkage compensation differences (5) Insufficient cooling time; product demolded before fully cooled, post-shrinkage causes deformation (6) On the original basis, additional attention is needed as process parameter fluctuations or equipment status changes have aggravated this problem

(1) Optimize product design; wall thickness as uniform as possible, rib thickness not exceeding 60% of wall thickness, enlarge fillets at corners (2) Control mold temperature uniformity, temperature difference not exceeding 5°C, reasonably set within the 40-90°C range (3) Extend cooling time, ensure the product is fully cooled and solidified before demolding, demolding temperature more than 10°C below heat deflection temperature (4) Optimize holding pressure scheme, adopt multi-stage holding pressure, ensure uniform shrinkage compensation in all cavity parts (5) Adjust gate position and number, make melt flow uniform, reduce molecular orientation differences (6) And strengthen process monitoring; on the original basis, additional attention is needed, with special attention to parameter stability

Warpage deformation is the core challenge of '2079851475616104452 crystalline materials; its essence is internal stress caused by non-uniform shrinkage, requiring systematic control from design, process, and mold in multiple dimensions. Targeted preventive measures need to be taken in different production scenarios.