Characteristics of clay and GCC pigment coatings containing synthetic polymeric thickeners

摘要

The use of synthetic polymeric thickeners has been steadily increasing in the paper coating industry.However,the relation between the adsorption of thickeners on pigments and the characteristics of coated papers has seldom been established.In this work,adsorption of various synthetic polymeric thickeners on coating pigments (i.e.clay and ground calcium carbonate) was determined.The influence of the thickeners on the surface and mechanical properties of coated paper was systematically investigated.It was found that the strong adsorption of certain types of thickener occurred particularly in clay pigments,which in turn increased the viscosity of coating mixtures and led to high fibre coverage and a smooth coated paper surface.GCC pigments appeared to be less sensitive to the thickener type.With the addition of the thickeners,burst,tensile strength and air permeability of coated papers were improved.Similar trends were observed for both GCC and clay pigments.