Teach you how to select and verify the accuracy and stability of injection molding machines?

Update:08-07-2021
Summary:

As one of the pillar industries of light industry, the […]

As one of the pillar industries of light industry, the injection molding industry has penetrated into all aspects of life. As the main equipment for injection molding production, injection molding machines coexist with high, medium and low grades, with a wide range of types and endless application types. Even many professionals in the injection molding processing industry are dazzled and it is difficult to choose the injection molding machine that suits their needs. . Many engineering and technical personnel of injection molding machine manufacturers will also compile some reference materials on how to choose injection molding machines, which are used when equipment manufacturers choose. However, the injection molding machine selection methods involved in these materials are generally too one-sided, focusing on the introduction of mold installation, injection volume and clamping force verification, etc., which is equivalent to the manual written by the mobile phone manufacturer, telling you that this mobile phone can make calls and send messages. Information, surfing the Internet and listening to music and other functions, but did not tell you why this mobile phone compares with other mobile phones, single screw and barrel why the Internet speed is not as fast as other mobile phones, and why the sound quality is better or worse, etc. The same is true for injection molding machines. Some injection molding machines have an injection position that can be accurate to 0.02 mm, and some injection molding machines fluctuate within 2 mm. The reason for this difference is not written by the technicians of injection molding machine manufacturers.

Basically, the introductions we have seen in the selection of injection molding machines in the past all require the injection molding machine to "sufficient injection volume, place the mold down, lock tightly, and fully shoot." In fact, the workshop technicians of the injection molding machine manufacturer know it. These rules, but sometimes the technicians just don't understand why this machine is better than the other machine next to it, and why the process parameters of this machine can't be used at all on another machine of the same model.
How can a technician distinguish the quality of an injection molding machine? Here is a simple way to verify the repeatability of an injection molding machine.

When setting injection parameters, set injection holding pressure, speed, and time to 0. When injecting products, first shoot the gate according to the normal parameter settings, then accelerate to the first stage, and then fill to 90-95% of the product full of glue. , To ensure that the product lacks a corner state, use the position injection method to shoot the glue, and ensure that the time of each injection is completely the same during the injection molding process (inconsistency indicates that the adjusted parameters are problematic, and the parameters cannot be guaranteed to be executed according to their own adjustment). If there is no change in temperature, repeatedly manufacture N pieces of products, weigh N pieces of trial-produced pieces, and draw the product weight change diagram, and you can see the product weight change circuit diagram. When the average weight deviation between the product and the N products exceeds 0.3%, then The stability of the machine is poor, exceeding 0.5%. The editor of Damxun recommends that the machine be overhauled.