Reasons for plastic injection molding parts deformation

During the production process of plastic injection molding parts, various deformation situations often occur, which may lead to a decrease in plastic products quality or even render it unusable. Therefore, understanding the causes of plastic parts deformation during injection moulding is crucial for improving product quality and avoiding waste.

The causes of plastic products deformation during injection molding can be divided into two categories: one is caused by the properties of the material itself, and the other is caused by operational issues during the processing.

1. Plastic parts deformation caused by the properties of the material itself

A. Thermal expansion and contraction: Plastic expands during heating and contracts after cooling, which can easily lead to changes in the size of the injection molded parts.

B. Poor melt fluidity: The viscosity and fluidity of plastic materials have a significant impact on the filling and filling properties during the plastic injection molding process. When the melt viscosity of the material is too high or the fluidity is poor, it is easy to cause defects such as incomplete filling or bubble, which can lead to deformation.

C. Uneven molecular structure: The uneven molecular structure of plastic materials is also an important cause of injection molded plastic parts deformation. During the plastic injection molding processing, uneven molecular structure can easily lead to stress concentration and injection plastic products deformation.

2. Deformation of plastic injection molded products caused by operational issues

A. Improper injection mould design: The design of the mold directly affects the shape and size of the injection molding part. If the design of the mold is not reasonable, such as uneven wall thickness, overly complex structure, etc., it is easy to cause deformation of the molded plastic parts.

B. Uneven heating process: During the heating process of injection molding production, if the heating is not uniform, it will lead to inconsistent thermal expansion and contraction of the plastic material, resulting in injection molded products deformation.

C. Improper cooling process: During the cooling process of injection moulding production, if the cooling is not sufficient or the cooling speed is too fast, it can lead to uneven shrinkage of the plastic material, resulting in deformation.

D. Improper injection pressure: The injection pressure during the molding process has a significant impact on the quality of the plastic molded parts. If the injection pressure is not appropriate, it is easy to cause deformation of the molded plastic products.

E. Injection molding speed too fast or too slow: Injection speed has a significant impact on the filling and fullness of the molded plastic articles. If the injection molding speed is too fast or too slow, it is easy to cause defects such as incomplete filling or bubbles in the molded components, which can lead to deformation.

3. To avoid plastic components deformation issues during the injection molding process, the following measures can be taken:

A. Reasonable selection of plastic materials: According to the requirements of the product, plastic injection moulding manufacturer should choose suitable plastic materials to ensure that the melt fluidity and thermal expansion and contraction performance of the material meet the requirements.

B. Design a reasonable mold: During the mold design process, injection mould manufacturer has to consider the shape and size requirements of the plastic molding parts, design the mold structure reasonably, ensure uniform wall thickness and simple structure, and reduce the possibility of deformation.

C. Injection molding manufacturer should professionally control the heating and cooling process: The heating and cooling process should be uniform and stable, avoiding excessive temperature gradients to reduce deformation caused by uneven thermal expansion and contraction.

D. Control injection pressure and speed: Based on the characteristics of plastic materials and product requirements, plastic injection molding manufacturers should reasonably control injection pressure and speed to ensure uniform filling and filling, and reduce the possibility of injection molded plastic parts deformation.

Plastic injection molded parts deformation is caused by various reasons, including the properties of the material itself and problems during operation. Understanding these reasons and taking corresponding measures can effectively avoid plastic molding articles deformation problems, improve product quality, and reduce production costs. By continuously improving and optimizing the molding process, the quality and competitiveness of plastic products can be further improved.