How to control the color difference of injection molded products?

The color of a product, as the first sensory perception of a product by consumers, largely affects whether consumers are interested in further understanding and consumption of the product. However, the color difference control of injection molded parts is an extremely complex production control work. How to improve the consistency of product appearance and color is a challenge that the current injection molding industry practitioners have to face. This paper discusses the influencing factors and control of color difference in injection molded parts. In order to better prevent and control the color difference problem of products, and reduce the scrap and customer complaints caused by the color difference problem in the production process.

 

 

The main factors affecting chromatic aberration

1. The role of raw resin

Many people in injection molding production may be surprised that the raw resin itself can affect the color, but the fact does exist, especially when the resin itself has a certain base color. Different types of plastic or the same model but different production batches, the product sometimes comes in color.

 

2. The influence of color masterbatch

Color masterbatch is the most important factor affecting color difference. The color quality of plastic products directly depends on the color of the masterbatch. The thermal stability, dispersibility and hiding power of the color masterbatch are not only indicators to test the quality of the color masterbatch, but also have a direct relationship with the color difference. Masterbatch is mainly composed of colorants, dispersants, and plastic raw materials. Among them, the colorant has the greatest influence on the color, and the slight change in the proportion of the colorant will directly affect the color of the product.

 

3. Influence of the compatibility of color masterbatch and raw material thumb

The uneven mixing of color masterbatch and raw resin will lead to different amounts of color masterbatch added in the injection cycle, resulting in color difference. The compatibility of the raw resin and the color masterbatch will affect the color of the product by affecting the uniformity of colorant dispersion. If the compatibility between the two is not good, it will also cause color difference.

 

 

Method of color difference control

1. Elimination of injection molding machines and mold factors. Choose an injection molding machine with injection molding capabilities. If the injection molding machine has problems such as material dead ends, it is best to replace the equipment. For the problems caused by the color of the mold gating system, exhaust grooves, etc., it can be solved by repairing the corresponding parts of the mold. The problems of injection molding machines and molds must be solved first, in order to organize production and reduce the complexity of the problem.

 

2. Eliminate the influence of raw resin and masterbatch. Controlling raw materials is the key to completely solving the problem of chromatic aberration. The obvious effect of the thermal stability of the raw resin on product color fluctuation cannot be ignored, especially when producing light-colored products. Choose high-quality masterbatch raw materials, such as our black masterbatch, white plastic masterbatch, multifunctional masterbatch, etc.;

 

3. Chromatic aberration adjustment

Since the raw materials, injection molding machines, molds and other factors are excluded before production, if color difference is found in production, in most cases, it is only necessary to determine whether the color masterbatch is mixed with the raw resin, or the injection temperature problem is the mixing problem to solve the mixing problem. Temperature issues can be adjusted by changing the temperature or back pressure.