Plastic Application – It is normally sufficient to tumble blend the pellets with the base resin and any additional colorants or additives before processing. Incorporation techniques should not subject the flakes to high shear forces.
Co-Extruded Powder Application – When using SPARKLE SILVET products for manufacturing powder coatings, care must be taken to maintain the aesthetics of the flake and to allow for safe incorporation. The blending of the SPARKLE SILVET with the powder coating resins should be carried out in a low intensity mixer. If this cannot be accomplished, the SPARKLE SILVET pellets should be added at the very end of a high intensity mixer cycle. The objective of mixing is only to distribute the SPARKLE SILVET throughout the batch and not to reduce the pellets to fine particles. When discharging the batch from the mixer to the extruder, the vessels should be bonded to the same electrical potential to prevent static electricity build up. Single or twin-screw extruders can then be used to provide proper dispersion of the SPARKLE SILVET into the powder coating resin. The metallic blend should be extruded below the curing temperature of the resin and then micronized to the proper size. Excessive shear at any point in this process can cause flakes to become folded or broken, thus creating a large number of smaller flakes. This will result in a reduced reflectivity of the flakes and a graying in color.