What should I do if the blow molding products have color difference?

What should I do if the blow-molded products just produced have a color difference? This situation is very common. It may be caused by the raw material master color and the temperature of the barrel. In this article, the editor will introduce how to deal with the color difference problem.

Extrusion blow molding machine for hdpe barrel

1. Uneven mixing of raw materials and masterbatch

Poor mixing of the raw materials with the color masterbatch will cause the color of the product to change. After the raw materials and the color masterbatch are evenly mixed, when they are fed into the hopper through the lower suction material, the color masterbatch is separated from the masterbatch due to electrostatic action, and it is easy to be adsorbed on the hopper wall, which is bound to cause The change in the amount of color masterbatch in the blow molding cycle, resulting in color difference. The most effective way is not to use a suction machine, but to use a hot air dryer, and use the method of manual feeding to prevent the color difference caused by the separation of the toner and the masterbatch.

Blow molding machine for angled neck bottle

2.In the blow molding process, it is often encountered that the temperature of the barrel changes sharply due to the failure of a heating ring or the uncontrolled long-burning of the heating control part, resulting in chromatic aberration. Generally, when the heating ring is damaged and fails, the color difference will be accompanied by uneven plasticization, and the uncontrolled long-burning of the heating control part is often accompanied by product gas spots, severe discoloration and even coking. Therefore, the blow molding process needs to check the heating part frequently, and replace and repair it in time when it is found that the heating part is damaged or out of control, so as to reduce the probability of such chromatic aberration.

Extrusion blow molding machine

3. Raw materials and masterbatch

The first two are due to the color difference caused by the blow molding process, and the other is the discoloration caused by the raw materials and the color masterbatch. Strengthen the storage inspection of the raw materials, use the same master color from the same manufacturer as much as possible, and do a good job in standard test batch production. 

The above are all the solutions to the chromatic aberration of blow-molded products. I hope my article can help you.