Composite coating milling

Table 9.1 shows a composition of a coating colour for sheet-fed offset typical for European coating mills. 

Functionalization of Colloidal Silica Nanoparticles and Their Use in Paint and Coatings 135 Table 9.8 Composition of mill base (positions 1-8) and letdown (positions 9-13) in acrylic paint formulations (FP2019/1 a-c). 

The main nutrients which are present in a paper mill effluent are carbohydrates from wood pulp or from waste paper, and also products which arise from their degradation. Compositions may be very variable and depend to a large extent upon the type and amount of waste paper, if any, which is being used. Recycled coated and surface-sized papers will introduce significant amounts of soluble polymers, in particular starch, which were used in the original surface treatment. 

One way which is often used to impart an artificial structure to the dispersion of a carbon black in a composite is to coat the particles of a moulding powder, e.g. 1 mm diameter particles of polyethylene, with a conductive carbon black by mixing them together in a ball-mill. If subsequent moulding does not shear the mixture too much (rotational casting is ideal) the black remains concentrated in a honeycomb-like network, and the overall conductivity is greatly enhanced over that of a uniform dispersion of the same proportion of black. 

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