How to select materials for two-color injection molds

The author has written about the difference between two-shot injection and two-shot injection. The advantage of two-shot injection is that it can realize one-shot molding of multiple materials. Choosing the right material is helpful for the molding of insert injection molding and the appearance and quality of finished injection molded parts to meet the needs of customers. Next, the author will talk about how to select two-color injection molds? 1. Wear resistance. When the blank is plastically deformed in the mold cavity, it flows and slides along the surface of the cavity, causing violent friction between the surface of the cavity and the blank, which causes the two-color mold to fail due to wear. Therefore, the wear resistance of the two-color mold material is one of the basic and important properties of the mold. Hardness is the main factor affecting wear resistance. In general, the higher the hardness of the two-color mold parts, the smaller the amount of wear and the better the wear resistance. In addition, wear resistance is also related to the type, quantity, shape, size and distribution of carbides in the material. 2. High temperature performance. When the working temperature of the two-color mold is higher, the hardness and strength will decrease, leading to early wear of the mold or plastic deformation and failure. Therefore, the two-color mold material should have high anti-tempering stability to ensure that the two-color mold has high hardness and strength at the working temperature. 3. Strong and tough. The working conditions of two-color molds are mostly very bad, and some often bear greater impact load, which leads to brittle fracture. In order to prevent the parts of the two-color mold from being brittle and broken suddenly during work, the two-color mold must have high strength and toughness. The toughness of the two-color mold mainly depends on the carbon content, grain size and organization state of the material. 4. Fatigue fracture performance. During the working process of the two-color mold, under the long-term action of cyclic stress, fatigue fracture is often caused. Its forms include low energy multiple impact fatigue fracture, tensile fatigue fracture, contact fatigue fracture, and bending fatigue fracture. The fatigue fracture performance of the two-color mold mainly depends on its strength, toughness, hardness, and the content of inclusions in the material. 5. Resistance to cold and heat fatigue. Some two-color molds are in a state of repeated heating and cooling during the working process, which causes the surface of the cavity to be pulled and pressure to change stress, causing surface cracks and peeling, increasing friction, hindering plastic deformation, and reducing dimensional accuracy. Cause the two-color mold to fail. Hot and cold fatigue is one of the main forms of failure of hot work molds. This type of mold should have high resistance to cold and heat fatigue. 6. Corrosion resistance. When some two-color molds such as plastic molds are working, due to the presence of chlorine, fluorine and other elements in the plastic, they will separate and resolve strong corrosive gases such as HCI and HF after being heated, which will erode the surface of the two-color mold cavity, increase its surface roughness and increase wear Invalidate. Therefore, it is necessary to choose materials with superior corrosion resistance in the processing of two-color molds. [Recommendation] Learn more: Precautions for designing continuous stamping die (2) Learn more: 6 precautions for designing continuous stamping die