What is the problem of color difference produced by blow molding?

What is the problem of color difference produced by blow molding?

1. Raw materials, color master problem:

In the use of master color, strengthen the inspection of raw materials into storage; Blow molding processing the same product as far as possible using the same manufacturer, the same brand master material, color master production. If you need to change the color master manufacturer, do a good sample test, in line with the standard, can start batch production.

2. Uneven mixing of raw materials and master colors:

Raw materials with the same color master mixed badly will also make the product color change. After the raw material and master color stirred evenly, through the suction material into the hopper, because of static electricity, the master color separation with the master material, easy adsorption on the hopper wall, which is bound to cause the change of the master color in the blow cycle, resulting in color difference. The most effective way is not to use suction machine, and the use of hot air dryer, with artificial feeding method to prevent color powder with master material separation caused by color difference.

3. The temperature of the cylinder affects the color difference:

In plastic blow molding processing, color difference is often caused by the failure of a heating ring or the heating control part is out of control. Generally, the color difference caused by the failure of the heating ring will be accompanied by uneven plastination, while the uncontrolled long burning of the heating control part is often accompanied by gas spots, serious discoloration and even coking of the product. Therefore, plastic blow molding processing needs to check the heating part frequently, and timely replacement and maintenance are found when the heating part is damaged or out of control, in order to reduce the probability of such color difference.

4. Problems in the adjustment of production process:

During the production process, the temperature, back pressure, blow cycle and color master amount of plastic blow molding processing should not be changed as far as possible when the production process parameters are adjusted. At the same time, it is necessary to observe the influence of process parameters on color.