Method for controlling color difference during injection molding of injection molding machine

- May 15, 2019-

Method for controlling color difference during injection molding of injection molding machine

The common defect in the injection molding machine injection molding is the color difference. It is not uncommon for the injection molded parts to be scrapped in batches due to the difference in the color of the matching parts.

There are many influencing factors in the formation of injection molding machine chromatic aberration, involving raw material resin, color masterbatch, color masterbatch and raw material mixing, injection molding process, injection molding machine, mold and so on. In the actual production process, we generally control the color difference from the following two aspects.

(1) Eliminate the influence of injection molding machine and mold factors. To select an injection molding machine with a capacity equivalent to that of an injection molded product, it is preferable to replace the vertical injection molding machine if there is a problem such as a dead space of the injection molding machine. For the color difference caused by the mold casting system, the exhaust groove, etc., it can be solved by the maintenance of the corresponding part of the mold. The injection molding machine and mold problems must be solved before the production can be organized to reduce the complexity of the problem.

2) Eliminate the influence of raw resin and color masterbatch. Controlling raw materials is the key to completely solving chromatic aberrations. Therefore, especially in the production of light-colored articles, the significant influence of the difference in thermal stability of the raw material resin on the color fluctuation of the product cannot be ignored. Most injection molding manufacturers do not produce plastic masterbatch or color masterbatch. Therefore, it is necessary to strengthen the control of raw materials in production management and raw material inspection. Firstly, strengthen the inspection of the raw material warehouse to ensure that the performance of raw materials meets the requirements; the same product and the masterbatch and masterbatch of the same brand should be used as much as possible for the production of the same product; secondly, for the masterbatch, we should conduct random inspection before the color master enters the factory and mass production. The color test should be compared with the swatch provided by the customer, and compared with the color master used in the previous and current times. In the comparison of chromatic aberration, it is better to use the color difference meter to detect if the color difference is within the allowable range or Depending on the color difference, it can be considered qualified; if the color shift of the color master is not large, the color difference can be adjusted by adjusting the color master; if the color master has a large deviation, it needs to be returned to the master.