Talking about the common faults and solutions of injection molds!

Author: MULAN - Plastic Molding Manufacturer

We all know that injection molds often cause some failures due to various reasons after being used for a period of time, so do you know what are the failures in the process of injection mold processing? Let's learn about it with injection mold processing manufacturers today. 1. The ejector pin is bent, leaking, and broken: the quality of the self-made ejector pin is better, but the processing cost is too high. Nowadays, standard parts are usually used, and the quality is average. What's more dangerous is that sometimes when the ejector rod is pushed out for a certain distance, the ejector rod will break.

As a result, the exposed ejector pins cannot be reset during the next clamping and can damage the mold. In order to solve this problem, the ejector pin was reground, and the fitting part of 1015mm was kept at the front end of the ejector pin, and the middle part was ground 0.2mm. After assembling all ejector pins, the assembly clearance must be strictly checked, usually within 0.05-0.08 mm, to ensure that the entire ejector mechanism can move back and forth freely.

2. Poor cooling or water leakage in the water channel: The cooling effect of the injection mold directly affects the quality and production efficiency of the product, such as poor cooling effect, large or uneven shrinkage of the product, resulting in defects such as warping and deformation. On the other hand, all or a part of the mold is overheated, so that the mold cannot be formed normally and production is stopped. In severe cases, moving parts such as thimbles will thermally expand and become damaged.

Please do not ignore this system due to complex mold structures or machining difficulties. 3. Fixed-distance tensioning mechanism failure: Because such mechanisms are set in pairs on both sides of the mold, their actions must be synchronized, that is, the mold is closed at the same time, and the mold is opened to a specific position at the same time. This mechanism has a short lifespan, avoid it if possible, you can switch to other mechanisms.

When the pulling force of the core is small, the fixed mold can be pushed out by the spring. When the core pulling force is large, the core can be used for sliding when the movable mold is retracted. The core pulling action is done first, and then the mold is separated, and the core can be pulled onto the mold using a hydraulic cylinder.

4. Inclined pin slider type core-pulling mechanism: The most common problem of this mechanism is insufficient processing and too small material. If the inclination angle A is too large, when the pulling force F is a certain value, the core-pulling The bending force of the inclined pin during processing is P = F / COSA, the inclined pin is deformed, the inclined hole becomes larger, and wear is prone to occur. At the same time, the upward thrust N = FTGA generated by the inclined pin on the slider is also greater, this force increases the normal pressure of the slider on the guide surface in the guide groove, thereby increasing the friction resistance of the slider when sliding, It is easy to cause uneven sliding and wear of the guide groove. The above is what Shanghai Mulan Precision Machinery Manufacturing Co., Ltd. shared with you about the failures that may occur during the production of injection molds. I hope it will be helpful to you! .