How to control the color difference of injection molding machine products? Today's Liansheng Small injection molding machine The manufacturer will briefly share with you:

1、 Eliminate the influence of injection molding machine and mold factors

Select the injection molding machine with the same capacity as the main injection molding products. If the injection molding machine has problems such as material dead angle, it is better to replace the equipment. The color difference caused by the gating system and the mold exhaust slot can be solved by repairing the mold at the corresponding part of the mold; Before organizing production, the problems of injection molding machine and mold must be solved to reduce the complexity of the problem.

2、 Reduce the impact of injection molding process adjustment

When the injection process parameters need to be adjusted due to non color difference, the injection temperature, back pressure, injection cycle and master batch consumption should not be changed as much as possible. At the same time, it is necessary to observe the influence of process parameters on color; If color difference is found, it shall be adjusted in time.

Try to avoid the use of injection molding processes with high injection speed and high back pressure, which may cause strong shearing effect, to prevent local overheating or thermal decomposition from causing color difference. Strictly control the temperature of each heating section of the barrel, especially the temperature of the nozzle and the heating section near the nozzle.

3、 Reduce the influence of barrel temperature on color difference

In production, it is often encountered that the heating ring is damaged and invalid or the heating control element is out of control and burns for a long time, resulting in sharp changes in the barrel temperature and color difference. The color difference caused by this reason is easy to judge; Generally speaking, the color difference caused by the damage and failure of the heating ring will be accompanied by uneven plasticization.

However, the heating control part of long-term out of control combustion is often accompanied by gas spots, serious discoloration, and even product coking. Therefore, heating elements should be checked frequently during production. If the heating element is damaged or out of control, it should be replaced and repaired in time to reduce the occurrence of this color difference.

4、 Eliminate the influence of raw material resin and masterbatch

The control of raw materials is the key to completely solve the color difference. Therefore, especially in the production of light color products, the obvious influence of the different thermal stability of resin raw materials on the color fluctuation of products cannot be ignored. Since most injection molding manufacturers do not produce plastic masterbatch or color masterbatch, we can pay attention to production management and raw material inspection.

That is, strengthen the warehousing inspection of raw materials; Try to use color masterbatch and color masterbatch of the same manufacturer and brand to produce the same product; For color masterbatch, sampling and color test shall be carried out before batch production, and compared with last time and this time. If the color difference is not large, it can be regarded as qualified, just like the color master batch with slight color difference.

The master batch can be remixed before use to reduce the color difference caused by uneven mixing of the master batch itself. At the same time, we also need to focus on testing the thermal stability of raw resin and color master batch. For products with poor thermal stability, we recommend the manufacturer to replace them.

5、 Master the influence of barrel temperature and masterbatch on product color change

Before adjusting the color difference, we must also understand injection molding machine The change trend of product color with temperature and color master batch; With the change of production temperature or master batch dosage, the product color change rule is also different; The change rule can be determined through the color test process; It is impossible to quickly adjust the color difference unless the change rule of the masterbatch color is known.