Warping in injection molding defects refers to a deviation in the shape of the molded product from the shape of the mold cavity, resulting in rotation or twisting of the product after demolding or shortly thereafter. Typical manifestations include undulations on flat surfaces of the product, with straight edges bending inward or outward.
Causes of Warping
Improper injection pressure and speed.
Uneven ejection action.
Uneven cooling.
Low melt temperature, resulting in differential shrinkage of the material.
Irregular cross-sectional thickness.
Remedies for Warping
Increase injection speed.
Optimize the demolding system.
Improve the cooling system.
Redesign product shape and dimensions according to resin characteristics.
Increase barrel temperature and screw back pressure.
