Understanding the Color Matching Process of Plastic Packaging 03
There are two methods to color the products. One is directly adding color powder into resin, the other is using color master batch.
The first approach only needs to mix color powder and plastic resin, and then the mixture can be sent to product molding room. Although it cost less time and money, its coloring force, uniformity and quality stability is very poor. Therefore, the second method is widely used in factories now.
●Color Master Batch
Color master batch is kind of colorant granules with certain concentration, by mixing the colorant, carrier resin, dispersant and other additives. During the product molding process, the engineer would add a certain amount of color master batch to let the products achieve the desired color effect.
Besides, the color master batch has a higher tinting strength, because of its pre-treatment of pigments. And it is very convenient to transit, store and use the color master batch due to its less dosage and stable properties, thus the environmental pollution is also greatly reduced.
The color master batch is usually classified by its carrier and purpose. For example, according to its desired coloring carrier resin, there are ABS color master batch, PC color master batch, PP color master batch and so on. And it can also be classified three major master batch according to application, for injection molding, blow molding and extrusion.
●Substances in Color Master Batch
The dispersants can remove the surface air by wetting and penetrating pigments, and disperse the condensates and aggregates into some fine, stable and uniform particles, which can even no longer be condensed in the machining process.
Other additives include coupling reagents, antioxidants, light stabilizers, antistatic agents and so on. Multifunctional master batch is made by fixing amount of additions, according to different needs and varieties. For instance, color master batch with brightener is conducive to release molding products and improve the surface brightness of molded products.