Methods Used for the Coloration of Plastics

The method for coloring a plastic material is always determined by the processing technique. In most cases, today, mixing of colorant with the powdered 

Dry color concentrates that are concentrated mixtures of resins and colorants are also used. They can contain up to 10 times as much colorant as is needed and are mixed with the uncolored resin during processing [2,7]. 

1 Some Examples of Methods Used for the Coloration of Most Important Plastics 

PE and PP. PE and PP are compounded at high temperatures it is then necessary to use pigments of high heat stability. Coloring is done by mixing in extruders and by the dry method. 

PS in its transparent state is colored with organic dyes in solution in aromatic hydrocarbons. The dye selected to color objects produced by injection molding must resist temperatures of up to 250°C. Small objects may be superficially colored by colorants soluble in appropriate solvents. 

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