1. The color powder has poor heat resistance, so it must be made at low temperature. Do not allow the material to stay in the extruder for a long time. If the filter screen of the extruder die is blocked, the accumulated material in the barrel will also cause discoloration. Materials with poor heat resistance cannot be granulated twice. The PVC resin that is easy to decompose can not be shut down during production to avoid discoloration of coke. If the color powder is shear resistant, the temperature can be properly reduced and the screw speed can be increased, so that the melt viscosity is increased, the shear transfer effect is large, the color powder dispersion is promoted, and the coloring force is enhanced.
2. The environmental requirements for the production of special black masterbatch on the film blowing machine are particularly high. Because most of the colorants are powder, the dust floating in the air is easy to pollute the environment. Isolation and timely cleaning between production lines are very necessary and cannot be ignored. Residues in the equipment will affect the next batch of products. The mixer, extruder, feeding device, storage tank and pelletizer must be cleaned thoroughly. The same kind of carrier resin can be produced from light color to dark color, and the dark color to light color must be cleaned by pulling the screw. The color masterbatch is manufactured before and after the same machine, and the color is affected due to the incompatibility caused by the change of carrier resin. Different processing temperature, melting temperature and decomposition temperature will cause discoloration of coke. If necessary, the screw must be pulled out for cleaning.