1.Directly colouring the resin powder, when colouring the powder, just add the pigment directly to the kneader to mix evenly.This type of kneader can be rotary type or high-speed type.When using high-speed kneading machine, ordinary pigments and other additives should be added to the resin powder to mix well, and pearlescent powder should be added at the end of mixing.This is because the high shear force will destroy the pearlite pigment flake crystal structure, affecting the pearlite effect.
2.For direct colouring of resin particles, pearlescent pigment cannot be directly added to the resin particles. Liquid coupling agent must be used to fix it on the surface of the resin particles to generate physical or chemical binding.In addition, emulsifier or high boiling solvent can be added to improve the wetting performance of the interface.In general, the amount of coupling agent is 0.2-0.5% of the resin dosage.A low molecular weight polyethylene powder of 1% can be added to the mixture of pigment and resin for better dispersion of pearlescent pigment in the resin.
3.Mix and mix the pearlescent pigment with solvent and organic pigment in advance to make liquid pigment, that is, the pearlescent paste. If pulping is made with organic pigment, grind the organic pigment to the specified fineness before mixing with the pearlescent pigment.The application of pearlite paste should be mixed evenly to prevent the precipitation of pearlite pigment, so as to ensure the consistency of the concentration of pearlite pigment in the pearlite paste.
4.Preparation of pearlescent masterbatch and the use of pearlescent pigment for the thermoplastic resin coloring, masterbatch method is the best effect.Common coarse and fine resin powder can be used to prepare color masterbatch, but it is better to first use high melting index, good fluidity, molecular weight double coated with low resin polymer as the carrier of pigment, color masterbatch preparation has two methods: continuous and gap: the general industrial production using twin-screw extruder for continuous production.
5.The preparation of 30% pearlescent masterbatch first premix 70 parts of PE particles with wetting agent, dispersant and other auxiliary agents, mixing time according to the size of batch and mixed strength, and then add pearlescent pigment mixed evenly, the mixture will be slowly added to the double screw rod extruder.Charging zone temperature is 140 ℃, mouth membrane temperature is 160-180 degrees, eager after extrusion granulating.
1.Improve the mixing effect of screw, so as to improve the pearl pigment dispersion uniformity;
2.Using a larger L/D and add filter net, can improve the pearl masterbatch coloring effect;
3.Within the allowable range,increase the processing temperature and reduce the damage to the crystal structure of pearlescent pigment flakes;
4.In order to get a better pearlescent color, mold surface finish and mold gate design is very important.The smoother the mold, the more uniform alignment and smooth uniform pearlescent color.Single sprue is better than multiple sprue, the location of the sprue should usually be at the original thick location away from the flow barrier, and the space distance between the end of the sprue and the runner system should be as small as possible.
Advantages of pearl powder added to plastic
Pearl masterbatch product was added to make products appear after a multi-angle attractive colors, improve product quality, enhance the visual effect.As we all know, pearlescent masterbatch having a metallic effect and natural pearl soft, decorative excellent products reach pearly shine effect.Customer demand for the production of different plastics used in a variety of colors pearl masterbatch, the product non-toxic green, heavy metal content in line with international standards.