For the coloration of plastic either dyes or pigments can be used.Due to their better performance with respect to thermal stability and light fastness,pigments dominate in almost all applications.One of the problems with pigments is,that they are not easily incorporated into the polymers in a homogeneous and finely dispersed manner.This leads to unwanted differences in shades and the formation of speckles etc.One way to improve the homogeneity is to intensify the mixing procedure by the use of special extruders and/or multiple extrusions of more or less concentrated pigment dispersions in polymers(Masterbatch approach).Another method is to coat the pigment particles with organic or inorganic layers which should prevent agglomeration of the particles and ease the incorporation into the polymer.Another problem is due to the very fine particle size of the pigments resulting in dust and problems with handling,cleaning and dosing.Hence the ideal pigment would have a rather large particle size for ease of handling and dosing and nicely disperse in the polymers without the need for multiple extrusion or special equipment.A novel cost optimized approach towards granular pigment preparations with excellent dispersibility will be presented and the performance will be compared to existing products on the market.The incorporation of pigments into plastics in a homogeneous and reproducible way was always difficult.The novel high performance and cost saving pigment preparations presented here can help to manage this problem,in a very efficient way.
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