Selection of color carrier (color powder carrier resin)
For TPE/TPR with different substrates or hardnesses, different color carriers are used, mainly considering that the melting point of the color masterbatch should be close to that of the main material, which is conducive to the full plasticization and good mixing of the color masterbatch and the main material during screw shearing and injection, so as to achieve the best color matching effect.
1) For TPE/TPR with SBS as the base, it is better to use polystyrene or EVA as the color carrier.
(2) For hard TPE/TPR with SEBS as the base, polypropylene color carrier is preferred.
(3) Softer TPE/TPR with SEBS as the matrix, it is better to use low-density polyethylene or ethylene vinyl acetate copolymer instead of polypropylene carrier, in order to avoid the hardness of the composite material being affected by polypropylene carrier.
(4) SBS, SEBS are not allowed to use PVC as the base color masterbatch.
(5) For some overmolded TPE/TPR applications, polyethylene coloring agent should be avoided, because polyethylene coloring agent may adversely affect the adhesion between TPE/TPR and the substrate.
The effect of TPE/TPR adhesive material characteristics on the color matching effect.
The first article above is to ensure the correctness of the color masterbatch (colorant) category, and then consider the influence of TPE/TPR adhesive material characteristics on the color matching.
1) The influence of specific gravity of TPE/TPR compound on color matching
For lighter weight materials, the filler content is less and the dose of color masterbatch or color powder added is small enough to achieve excellent color matching effect. In the case of other blending system, add quantitative color masterbatch/colorant to compare the color matching effect - transparent TPE is the best, with bright color and less colorant added; translucent TPE is the second best, with better color matching; solid TPE has much inferior color matching effect. It can be understood that the higher the specific gravity, the worse the color matching effect.
2) Influence of TPE/TPR rubber compounding system
The influence of specific gravity on color matching. The specific gravity is mainly affected by the filler (such as calcium carbonate, etc.). Therefore, the quality of calcium carbonate (such as color, fineness and compatibility with the system, etc.) has a greater impact on the color matching effect.