Do you know the basic principles to be achieved when selecting materials for plastic injection moulds? If you are still unclear, come and have a look with us now.
1. Abrasion resistance
In the process of plastic deformation of the blank in the cavity, the blank flows and slides along the surface of the cavity, causing friction between the surface of the cavity and the blank. Therefore, the wear resistance of the material is one of the most basic and important properties of the mold.
The main factor affecting wear resistance is hardness. Generally, the higher the hardness of plastic injection mould parts, the smaller the wear and the better the wear resistance.
Most of the researches on the working environment conditions of the mold are very harsh, and some of them are often able to withstand large impact loads, which can lead to brittle fracture. To prevent sudden brittle fracture of mold design parts during work, the mold must have relatively high strength and toughness.
The toughness of the mold mainly depends on the carbon content, grain size, and microstructure of the material.
3. Fatigue fracture performance
In the development process of mold design work, under the long-term influence of cyclic stress, it can often lead to fatigue and fracture of students. Its forms include small energy fatigue fracture through multiple impacts, tensile fatigue fracture, contact fatigue fracture, and bending fatigue fracture.
The main development of the fatigue fracture system performance research of the mold depends on its strength, toughness, hardness, and the content of inclusions in the material.
4. High-temperature performance
When the working temperature of the plastic Injection mould is high, it will lead to a decrease in strength and hardness, resulting in abrasion and deformation, so a certain degree of anti-tampering stability is required.
5. Resistance to cold and heat fatigue
Some molds are repeatedly heated and cooled during processing, causing the surface of the cavity to be pulled and pressure to change the stress, causing surface cracking and peeling, increasing friction, hindering plastic deformation, reducing dimensional accuracy, and causing mold failure. Heat and cold fatigue are one of the main failure modes of hot work molds. This type of mold should have high resistance to cold and heat fatigue.
6. Corrosion resistance
Some plastic Injection moulds will produce strong corrosive gas after being heated, which will erode the surface of the mold cavity, increase its surface roughness, and aggravate wear. Therefore, a certain degree of corrosion resistance is required.