PBT injection molding problems and solutions

PBT is a common engineering plastic, with excellent heat resistance, mechanical strength and chemical resistance, widely used in electronics, automotive, aerospace and other fields. However, in the process of PBT injection molding, you may encounter some problems, the following will introduce some common PBT injection molding problems and solutions.

Shrinkage rate: The shrinkage rate of PBT is small, generally 1.5 to 2.5‰. However, in the actual molding process, there may still be product defects caused by uneven shrinkage. The solutions include: optimizing gate design, adjusting injection pressure, increasing mold temperature, etc.

Stress cracking: PBT products may crack or break when subjected to stress. This is usually caused by residual stress inside the product or by external stress concentration. The solutions include: optimizing product design, increasing product thickness, reducing injection pressure, etc.

Warping deformation: Warping deformation refers to the uneven surface of the product during the molding process. This is usually caused by asymmetrical product structure or inconsistent shrinkage rates. The solutions include: optimizing product design, adjusting gate position, adjusting injection pressure, etc.

Silver stripes: Silver stripes are small cracks or textures that appear on the surface of the product. This is usually caused by the presence of stress, moisture, or other impurities inside the product. Solutions include: optimizing product design, reducing injection pressure, increasing mold temperature, etc.

Bubbles: During the injection process, if the air is not sufficiently discharged, it may cause bubbles to form inside the product. The solutions include: optimizing gate design, reducing injection speed, increasing mold temperature, etc.

There are many problems that may occur in the PBT injection molding process, but the solutions are also numerous. In actual operation, analysis and debugging should be carried out according to specific problems in order to effectively improve the stability and pass rate of product quality. At the same time, reasonable process parameter setting, correct mold design and strict quality control are also key factors to ensure the smooth progress of PBT injection molding.