How To Make Good Quality Mold And Choose Suit Steel

The steel of the injection mold is like the foundation of a house. If there is no suitable material, the mold will not meet the requirements. Today I will explain the knowledge of mold steel.

Before talking about mold materials, we must first understand some basic things about injection molds. The first is the classification of molds. Tuofang generally divides molds into five levels according to the length of service life. The first level is more than one million times, and the second level is 50. Ten Thousand-1 million times, the third level is between 300,000-500,000 times, the fourth level is between 100,000-300,000 times, the fifth level is less than 100,000 times, the first and second level molds are both It is required to use steel that can be heat treated with a hardness of about HRC50, otherwise it is easy to wear and the injection molded product is easy to be out of tolerance. Therefore, the selected steel must have good heat treatment performance and good cutting performance under high hardness. , Of course, there are other considerations. Because I rarely come into contact with domestic plastic mold steel, I can only introduce imported materials commonly used in Huangyan. Usually choose Sweden's 8407, S136, American 420, H13, Europe's 2316, 2344,083, or Japan's SKD61, DC53 (formerly metal mold materials, used under special circumstances.) and other steel.

In addition, the raw materials for injection molding and the added fillers have a great influence on the selection, especially the glass fiber wears a lot to the mold.

Some plastic materials are acid corrosive, and some are added with reinforcing agents or other modifiers. For example, glass fiber can cause great damage to the mold, so comprehensive consideration should be given to the selection of materials. For highly corrosive plastics, generally choose S136, 2316, 420 and other steels. In addition to S136, 2316, 420, there are also SKD61, NAK80, PAK90, 718M for weak corrosive plastics.

Strongly acidic plastic materials include: PVC, POM, PBT. Weakly acidic plastic materials include: PC, PP, PMMA, PA. The appearance requirements of the product also have a great influence on the selection of mold materials. Transparent parts and surfaces require mirror finish. For the products, the available materials are S136, 2316, 718S, NAK80, PAK90, 420, the mold with high transparency should be S136, followed by 420.