Why does the plastic masterbatch have color difference?

In the process of manufacturing plastic masterbatch, color difference is a very important quality control standard. This article mainly analyzes the causes of chromatic aberration from the aspects of materials, operation technology, human factors and surrounding environment, hoping to help you.

 

 

Analysis of the causes of color difference in plastic masterbatch

1. Raw materials

At present, if the heat resistance, shear resistance and dispersion of the toner are not the same, the corresponding color difference will occur. Except for a small number of inorganic pigments, most inorganic pigments have relatively high heat resistance and usually do not adversely affect the production of ordinary color masterbatches. The heat-resistant temperature of the relevant pigment itself varies to a high degree.

 

Acidic substances are often present during resin processing. In the ultramarine blue molecule, there is a certain amount of sulfide, which will react after encountering the acid. The existing iron oxide pigments can have a good effect on the resin. Pigments and resins are not compatible, often discoloration, and during operation, try to avoid combining the two together.

 

Under normal circumstances, when using a machine to make a sample, the dispersibility of the toner is improved, and the color density increases accordingly. If the color density of one of the colors increases, the color difference problem will occur. In response to this phenomenon, it is reasonable to of adjustment color particles. The use of pre-dispersed pigments to make small samples can prevent problems from occurring.

 

 

2. Reasons for processing equipment

Starting from the processing performance of raw materials, formulate corresponding process conditions, and formulate general process conditions for different types of resins and toners. Moreover, in order to ensure the occurrence of small color differences between batches of the same color masterbatches, the consistency of equipment and operating processes should be enhanced, otherwise, color differences will inevitably occur.

 

(1) Mixing. For the mixing process, in addition to focusing on the shear resistance of the toner, it is also necessary to avoid mixing together to cause the occurrence of chromatic aberration. The color difference caused by uneven mixing has a certain error in the local sampling, and the mixing after granulation ensures the uniformity of the color.

 

(2) Extrusion. The heat resistance of the colorant itself is not high. When making the black or white masterbatch, the low temperature should be kept, and the material should not be kept in the machine all the time. The material with low heat resistance cannot be granulated for the second time. Minimize downtime during production to prevent discoloration.

 

3. Environmental reasons

During the production of color masterbatch particles, very strict requirements are placed on the surrounding environment. This is because the colorant is a kind of powder, which is easy to pollute the environment, and the isolation between the production lines should be completely cleaned up.

 

4. Human Factors

Human factors include the variety of feeding materials does not meet the requirements, the processing technology is unreasonable, etc., the sample dilution resin does not match the standard sample, etc., the sample dilution ratio is inconsistent, the machine is not cleaned up, the product is often affected, and there are errors in the calculation results, etc.

 

 

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