Solution to color difference of blow molded products

Manipulating raw materials is the key to solving the color difference of blow molding products. If the new material is used to control the parameter temperature, the color difference of the blown product due to the formation of the material is basically impossible. If the return material is increased, the color value of the returned material and the uneven mixing during the mixing process appear Blown products suffer from color problems. If the production increases the return material, it is necessary to adjust the increase ratio and the mixing time according to the performance of the return material to ensure uniform material and reduce the color difference of the blown product.

 

1. Problems with quality and color masterbatch When using color masterbatch, strengthen the inspection of raw materials storage; use the same manufacturer, the same brand masterbatch and color masterbatch for the same product in blow molding. If you need to replace the masterbatch manufacturer, do a sample test and meet the standards before you start batch production.

 

2. The problem of uneven mixing of material and color masterbatch Mixing of the material and the color masterbatch will change the color of the product. After the material and the color masterbatch are evenly mixed, when they are fed into the hopper through the lower suction, the color masterbatch is separated from the masterbatch due to the electrostatic effect, and it is easy to be adsorbed on the hopper wall. This will inevitably lead to the change of the amount of the color masterbatch during the blow molding cycle, and then color difference . The most effective method is not to use a suction machine, but to use a hot air dryer, and use manual feeding to prevent the color difference caused by the separation of the toner from the master batch.

 

3.The problem that the barrel temperature affects the color difference

During the processing of blow molding products, it is often encountered that a certain heating ring is damaged and fails, or the heating control part is out of control and long-term burning, which results in a drastic change in the barrel temperature and then a color difference occurs. Generally, the color difference caused by the failure and failure of the heating coil will be accompanied by uneven plasticization, and the uncontrolled long-term heating of the heating control part is often accompanied by product air spots, severe discoloration and even coking. Therefore, in the blow molding process, it is necessary to frequently check the heating part, and timely replace and repair it when it is found that the heating part is damaged or out of control, so as to reduce the occurrence of such color differences.

 

4. Problems during production process adjustment When adjusting the blow molding process parameters during production, try not to change the blow molding temperature, back pressure, blow cycle and color masterbatch participation. Adjustments also need to observe the effect of process parameter changes on color.