Basic Knowledge Of Plastic Bottle Technology

Color matching and coloring process
For color matching and coloring, toner can be directly added to resin, toner mixed with resin extrusion and masterbatch method.

Toner directly added to the resin method:

After the toner is directly mixed with the plastic resin, it is sent to the next step of the product molding process. The process is short and the cost is low, but the working environment is poor, the coloring power is poor, the coloring uniformity and quality stability are poor.

Toner mixed resin extrusion method:

This method has a better effect on the uniformity of resin and color, and can fully disperse the pigment in the resin, with accurate color, clean quality and easy processing.

Masterbatch method:

Colorant, carrier resin, dispersant, and other additives are formulated into pellets with a certain concentration of colorant. When the product is formed, a certain amount of color masterbatch is added according to the coloring requirements, so that the product contains the required amount of colorant and meets the coloring requirements.

Color masterbatch can be classified according to the coloring resin, such as ABS masterbatch, PC masterbatch, PP masterbatch, etc.; it can also be classified according to the coloring resin processing technology, there are three types of masterbatches: injection molding, blown film, extrusion grade . Due to the pretreatment of the pigments, the color masterbatch has high tinting strength, the dosage can be reduced and the quality is stable, the transportation, storage and use are convenient, and the environmental pollution is greatly reduced.

The dispersant removes surface air by wetting and penetrating the pigment, disperses the aggregates and aggregates 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 blacks 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 produced by polyethylene cracking. Other additives include coupling agents, antioxidants, light stabilizers, antistatic agents, fillers, etc. The amount added depends on the requirements and varieties. They are called multifunctional masterbatches. Adding brighteners is beneficial to molding products. Release the mold and improve the surface brightness of the product.

The performance indicators of masterbatches include color difference, whiteness, yellowness, yellowing degree, thermal stability, oxygen index, melt flow rate, etc. Of course, the fineness, migration, chemical resistance and toxicity of pigments are also related to the color masterbatch. Some indicators are very important in special purposes, such as the fineness of the filter press value (DF value) of fiber-grade masterbatches.