Basic knowledge of color matching and process of plastic bottles (2)

Color matching process
Color matching and coloring can adopt the method of adding the toner directly to the resin, the extrusion method of the toner mixed resin and the masterbatch method.
Toner is directly added to resin method:
After the toner is directly mixed with the plastic resin, it is sent to the next step of the product forming process, which has a short process and low cost, but the working environment is poor, the coloring power is poor, and the color uniformity and quality stability are poor.
Toner mixed resin extrusion method:
This method has the best effect on the uniformity of resin and color. It can fully disperse the pigment in the resin, the color is accurate, the quality is clean, and it is easy to process.
Masterbatch method:
It is the colorant, carrier resin, dispersant, and other auxiliary agents to formulate a certain concentration of colorant pellets. When the product is formed, a certain amount of masterbatch is added according to the coloring requirements to make the product contain the required amount of coloring to meet the coloring requirements.
Color masterbatch can be classified according to the resin to be colored, such as ABS masterbatch, PC masterbatch, PP masterbatch, etc.; it can also be classified according to the coloring resin addition process. There are three types of masterbatch for injection molding, blown film, and extrusion. . The color masterbatch has high tinting strength due to the pretreatment of the pigment first, the dosage can be reduced, the quality is stable, the transportation, storage, and use are convenient, and the environmental pollution is greatly reduced.
The dispersant removes the surface air by wetting and penetrating the pigment, disperses the aggregates and agglomerates into fine, stable and uniform particles, and no longer aggregates during processing. The commonly used dispersant is low molecular weight polyethylene wax. For organic pigments and carbon black that are difficult to disperse, EVA wax or oxidized polyethylene wax is used. There is a big difference between synthetic low-molecular-weight polyethylene wax and low-molecular-weight polyethylene wax made by polyethylene cracking. Other auxiliaries include coupling agents, antioxidants, light stabilizers, antistatic agents, fillers, etc., depending on the requirements and varieties, called multi-functional masterbatch, and if the brightener is added, it is beneficial to molded products. Demould and improve the surface brightness of the product.
The performance indicators of the color masterbatch include color difference, whiteness, yellowness, yellowness, thermal stability, oxygen index, melt flow rate, etc. Of course, the fineness, migration, chemical resistance, and toxicity of the pigment are also related to the color masterbatch. Particle performance is related, and some indicators are very important in special applications, such as the filter pressure value (DF value) fineness of fiber-grade masterbatch.

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