Ten factors affecting the quality of injection molds
1. Mold Steel Steel is the decisive factor in the quality of injection molds, and choose the right steel is the top priority. The standard for choosing steel is
①Injection molding material requirements Different plastics should use different steels, such as high polishing requirements, corrosion resistance requirements, etc.
②Price Steel can be used as well, not the more expensive the better; considering the cost factor of injection mold, the mold steel should use materials corresponding to the mold life to avoid unnecessary waste; the life of general P20 material is about 300,000 shots; 2738 material there is no problem to reach 500,000 shots, H13/2344 is usually more than 0.8-1 million shots, and can be selected according to the situation; ③Surface treatment The surface treatment of the mold is also very important. Nitriding can enhance the surface hardness of steel and effectively extend the mold life. Electroplating can effectively modify the mold steel. For some high-brightness and corrosion-resistant plastic parts, electroplating can be used to enhance and improve the performance of the steel.
2. Structure Design The mature injection mold structure not only considers the material properties of the product, shrinkage rate, molding temperature, elastic tensile deformation coefficient, etc., but also considers the cooling water passage, the speed of opening and closing the mold. The reasonable mold structure can effectively extend the mold life and ensure the smooth production of the mold, improve efficiency and reduce costs.
3.Mold Manufacturing If a worker wants to do something good, he must first sharpen his tools. The arrangement of the injection mold process is particularly important, and the reasonable process arrangement can speed up the production lead time, shorten the processing time, and effectively save costs. And more importantly, accurate and reasonable processing can ensure the stability and longevity of the mold during the production process. Some processing errors will lead to more serious is that have to re making of the mold. In addition, poor processing may affect the mold movement and reduce the mold life, resulting in cracking or breaking of the mold during the production process.
4. Standard Parts The lowest bar is the one that determines the capacity of the bucket. Everyone understands this truth, but it is often not noticed when doing it. The mold is the same, although the standard parts are not directly involved in the molding, but control the operation of the entire mold. Good standard parts should be wear-resistant, hard enough, high precision, and not easy deformation. Different brands of standard parts are very expensive, so don’t blindly budget the mold prices, always believe that good cost good products.
5.Spotting The mold clamping relies on the experience of the mold makers, it seems simple work but need experience most. The main thing about complex molds is this effort. The plate mold is the simplest, and the fractal surface is basically OK as long as there is no flash break. It is very troublesome if it is a car accessory mold. Not only is the fractal surface relatively irregular, but it often includes multiple sliders and top blocks. At the same time, it can improve and prevent other problems of the mold through the touch, so it is a comprehensive work.
6.Polishing The polishing of the mold is the last step in the manufacture of the mold. Polishing is directly reflected on the plastic part, so this is the most face-to-face job. Polishing also helps and complements the mold movement, especially for demolding. Often some mold production is not smooth because the lighting is not in place, the resistance is too large, the demoulding is difficult, and even the white, the top crack and so on.
7.Mold Assembly Mold assembly is like assembling a machine. Every component and every screw can’t go wrong. Otherwise, the consequences will be quite serious. If it is light, it will lead to product defects, affecting production, and completely damage the mold and cause scrapping. Therefore, the assembly work must be very carefully. In the assembly process, especially pay attention to the cleaning of the mold, especially the water circuit and screw holes. Be sure to blow off the iron filings inside.
8.Hot runner or cold runner This actually has the least impact on the quality of the mold, because the hot runners are generally branded by customers, especially some large customers. Well-known foreign brands do very well in quality and after-sales service, so there is generally no problem in quality.
9.Cooling Anyone who has experience with injection molds knows how important cooling is to a mold. Due to the increase in prices and labor wages, it is unthinkable to reduce the profit from the one-second injection cycle time during the mass-production. However, when the production cycle time is accelerated, the temperature of the mold will rise. If it is not effectively controlled, the mold will be too hot to be formed, and even the mold deformation will be scrapped. Therefore, excellent waterway design is particularly important, including the arrangement density of waterways, diameters, links between each other, and so on.
10.Mold maintenance Injection mold maintenance is mainly maintain and repair during the production process. The mold is like a car. If it is not used for a long time without maintenance, it may cause the mold to be scrapped. Therefore, every time the mold is used, it must be fully maintained, especially the rust prevention of the molded part and the rust prevention of the main moving parts. Because the mold has to connect cooling during the production process, it may fall into the mold during the installation or dis assembly process, so be sure to dry the mold and then apply a layer of oil protection.