Steel is the decisive factor in the quality of the mold […]
Steel is the decisive factor in the quality of the mold, and choosing the right steel is the top priority. The criteria for choosing steel are:
1 requirements for injection molding materials - different plastics should use different steels, such as requirements for high polishing, corrosion resistance, etc.;
2 price - steel can be used, not the more expensive the better; considering the cost of the mold, the mold steel should use the material corresponding to the life of the mold to avoid unnecessary waste; the life of the general P20 is about 300,000; 2738 500,000 is no problem, H13/2344 is usually more than 80-100 million, and can be selected according to the situation;
3 heat treatment. The surface treatment of the mold is also very important. Nitriding - can enhance the surface hardness of steel, effectively extend the life of the mold; electroplating - can effectively modify the mold steel, for some high-brightness and corrosion-resistant plastic parts can use electroplating to enhance and improve the performance of steel
2. Structural design
Pipe structure design
The mature mold structure not only takes into account 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, and the like. Reasonable mold structure can effectively extend the life of the mold and ensure the smooth production of the mold. Improve efficiency and reduce costs.
3. Mold processing
If a worker wants to do something good, he must first sharpen his tools. The arrangement of the mold process is particularly important, and the reasonable process arrangement can speed up the production cycle, 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 machining errors will lead to mold welding, no matter how good the welding is, it is a loss to the mold; in addition, poor processing may affect the mold movement, reduce the mold life, and cause the mold to crack during the production process. Even broken.
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 suitable for deformation. Different brands of standard parts are very different, so don't just kill the mold, kill it, and your mold will drop from Mercedes to the public.
5. Collision (flying mode)
It is the experience of the mold fitter that touches the seemingly simple work but the most technical work. The main thing that looks at complex molds is this effort. The flat mold is the simplest, and the fractal surface is basically ok as long as there is no flash break. It is very troublesome to use 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, through the collision, other problems of the mold can be improved and improved. So it is a comprehensive job.
6. Polishing / skin texture
The polishing of the mold is the last step in the manufacture of the mold. Polishing is directly reflected on the plastic parts, 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.