When tarpaulin is dyed, there are mainly two commonly used processes, namely the method of directly adding toner to resin and the method of masterbatch. 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. In the masterbatch method, the colorant, carrier resin, dispersant, and other additives are prepared into pellets with a certain concentration of colorant. 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 colorant. Meet the coloring requirements. Generally speaking, the performance indicators of color masterbatches include color difference, whiteness, yellowness, yellowness, thermal stability, oxygen index, melt flow rate, etc. Of course, pigment fineness, migration, chemical resistance, and toxicity It is also related to the performance of the masterbatch. Some indicators are very important for special purposes, such as the fineness of the filter pressure value (DF value) of the fiber-grade masterbatch.
However, it should be noted that the dispersant removes surface air by wetting and penetrating the pigment, dispersing the aggregates and agglomerates into fine, stable and uniform particles, and no longer agglomerates during processing. Common dispersants are For low molecular weight polyethylene wax, EVA wax or oxidized polyethylene wax is used for organic pigments and carbon black that are difficult to disperse. There is a big difference between synthetic low molecular weight polyethylene wax and low molecular weight polyethylene wax made by polyethylene cracking method. 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.
