Effect of coating formulations and drying methods on the coverage and smoothness of brown grade base papers

Abstract The Corrugated container industry asks papermakers to produce highly attractive linerboard with good multicolor printing properties to improve product appeal as much as possible at low cost to consumers. To meet this requirement, it is necessary to improve the visual appearance and printing properties of conventional linerboard which is made from recycled fibers for economic and environmental reasons. To meet this challenge, two new technologies, hot press drying and curtain coating, which make a strong combination as a method to produce high quality coated linerboard, were used. Hot press drying improved the smoothness of the linerboard and decreased the coating penetration, resulting in better surface smoothness after the coating process. The influence of the pigment composition on the brightness, gloss and smoothness of single or double coated linerboard was examined. Clay outperformed calcium carbonate by improving the brightness and gloss for coated linerboards, suggesting that the hiding power is more important than scattering characteristics when considering the pigment to be used in linerboard coating. The dynamic surface tension of the coating color decreased with the addition of a surfactant. It was shown that a surfactant that provides the curtain stability and less foaming should be used in the curtain coating. Mill experience from Dong-Il Paper Mfg. Co. started the twolayer curtain coating operation at the end of 2008 was described.