Industry News

Ten factors affecting the quality of injection mold

2020-05-13
1. Mold steel Steel is the decisive factor for the quality of the mold. Choosing a reasonable steel is the top priority. The selection criteria for steel are:

① Requirements for injection molding materials Different plastics should use different steel materials, such as high polishing requirements, corrosion resistance requirements, etc .;

② The price of steel can be used as much as possible, not as expensive as possible; considering the cost factors of the mold, the steel material of the mold should be selected according to the life of the mold to avoid unnecessary waste; generally the life of the P20 material is about 300,000 2738 material is no problem at 500,000, H13 / 2344 is usually more than 800-1 million, you can choose according to the situation;

③ Surface treatment The surface treatment of the mold is also very important. Nitriding can enhance the surface hardness of the steel and effectively extend the life of the mold; electroplating can effectively modify the mold steel. For some plastic parts that require high brightness and corrosion resistance, electroplating can be used to enhance and improve the performance of the steel.

2. Structural design The mature mold structure not only takes into account the product material properties, shrinkage rate, molding temperature, elastic tensile deformation coefficient, etc., but also takes into account the cooling water path and the speed of opening and closing the mold. 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 the worker wants to do his job well, he must first sharpen his weapon. The arrangement of the mold process is particularly important. A 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 of the mold in the production process and extend the life. Some processing errors may lead to mold welding, no matter how good the welding is, it is a loss for the mold; in addition, poor processing may also affect the mold movement, reduce the life of the mold, and cause the mold to crack during the production process Even broken.

4. Standard parts It is the lowest wooden bar that determines the capacity of the bucket. Everyone understands this truth, but when doing it, they often fail to notice it. The same is true of the mold. Although the standard parts are not directly involved in the molding, they control the operation of the entire mold. Good standard parts should be wear-resistant, hard enough, high precision, and not suitable for deformation. The price difference of standard parts of different brands is very large, so don't just kill the price when you make the mold, kill it, your mold will be reduced to the public from Mercedes-Benz.

5. Confrontation (flying model) Confrontation is the experience of the mold fitter. The seemingly simple work is the most technical work. Complicated mold mainly depends on this effort. The flat mold is the simplest, as long as the fractal surface has no burr breakage, it is basically ok. Auto parts molds are very troublesome. Not only are the fractal surfaces irregular, but they often include multiple sliders and top blocks. At the same time, other problems of the mold can be improved and perfected through the collision, so it is a comprehensive work.

6. Polishing / Dermatoglyphics The polishing of the mold is the last link in the manufacture of the mold. Polishing is directly reflected on the plastic parts, so this is the most face-saving job. Polishing can also play a role in helping and supplement the mold movements, especially for demolding. Often the production of some molds is not smooth because of insufficient lighting, excessive resistance, difficulty in demolding, and even top whiteness and cracking.

7. Mould assembly Mould assembly is just like assembling the machine. Every component and every screw can't make mistakes, otherwise the consequences will be quite serious, ranging from product defects to production, and from damage to the mold, causing scrap. Therefore, the assembly work must be very meticulous. During the assembly process, pay particular attention to the cleaning of the mold, especially the waterway and screw holes, and be sure to blow the iron scraps inside.

8. Hot runner or cold runner This actually has the least impact on the quality of the mold, because hot runners are generally designated by customers, especially some large customers. The well-known foreign brands are in place in terms of quality and after-sales service, so there is generally no problem in quality. However, some domestic hot runners have very different quality. In order to save costs, individual small enterprises strive for price advantages, and use some unreliable heating and conduction accessories, which is prone to problems. The main problem of the cold runner is how to ensure the balance of injection molding, gate size, injection pressure and so on.

9. Cooling Waterway Anyone who has experience in mold knows how important cooling is for a mold. Due to the increase in prices and manpower wages, when mass-produced products, the profits brought by the injection cycle without reducing by one second are unimaginable. But speeding up the production cycle will increase the temperature of the mold. If it is not effectively controlled, the mold will be too hot to form, and even the mold will be deformed and scrapped. Therefore, good waterway design is particularly important, including waterway arrangement density, diameter, and mutual links.

10. Mold maintenance

Mold maintenance is mainly the maintenance and maintenance in the production process. The mold is just like a car. If it is not used for a long time without maintenance, the mold may be scrapped. Therefore, every time the mold is used, it must be fully maintained, especially the rust prevention of the molding part, and the rust prevention of the main moving parts. Because the mold is exposed to water during the production process, it may fall on the mold during installation or disassembly, so make sure that the mold is dry, and then apply a layer of oil to protect it.