What is the impact of material selection on the performance of plastic injection molds

The material selection of a plastic injection mold is one of the decisive factors in its performance and life. Different materials have different characteristics such as strength, hardness, and wear resistance. Therefore, a reasonable combination of material selection is crucial to the performance of the mold.

Strength and Hardness

The strength and hardness of the mold material are key indicators that affect its performance. During the injection molding process, the mold needs to withstand the strong force from the plastic injected at high pressure, so a material with sufficient strength and hardness needs to be selected to prevent the mold from deforming or cracking. Commonly used mold materials include tool steel, stainless steel, carbide, etc., which can provide sufficient strength and hardness to cope with the high stress and high temperature environment during the injection molding process.

Wear resistance

Since injection molds need to be in contact with plastic materials for a long time during the injection molding process, the wear resistance of the mold becomes a crucial consideration. Choosing materials with good wear resistance can slow down the wear rate of the mold and extend the service life of the mold. Commonly used methods to improve wear resistance include selecting materials with high hardness, using surface coating technology, and surface treatment (such as nitriding, carburizing, etc.) to improve the wear resistance of the mold.

Thermal Conductivity and Cooling Performance

During the injection molding process, the mold needs to control the temperature through a cooling system to ensure rapid solidification of the plastic. Therefore, the thermal conductivity and cooling performance of the mold material are also important factors affecting performance. Excellent thermal conductivity can help effectively dissipate heat, prevent mold overheating, and improve production efficiency. Materials such as aluminum alloys generally have good thermal conductivity and are suitable for injection molds that require rapid cooling.

Processing performance

The processing performance of mold materials is directly related to the mold manufacturing process. Usually, the manufacturing of molds requires the use of advanced CNC machining and other processes, so the mold materials need to have good cutting and processing properties. Some free-machining tool steels or alloy steels are common choices, and they can produce high-precision mold parts through precision machining processes such as CNC machining.

Corrosion and corrosion resistance

Since injection molds may be exposed to various plastic materials and chemicals during use, the corrosion resistance of the mold material is also a factor that needs to be considered. Corrosion-resistant materials such as stainless steel are often used to manufacture molds to ensure that the molds are not damaged by chemical corrosion during long-term use.