New water-based barrier coatings for paper and paperboard

Abstract

Results obtained with new water-based barrier coatings for paper and paperboard are presented. These coatings include polyester-based coatings, dispersions containing hydrophobic monomers and coatings made from biodegradable polymers. Coatings were tested as such, some were filled with talc and some were used as an additive in a commercial polymer dispersion. Relatively good barrier values were achieved. However, work needs to be done to optimise the properties of biodegradable polymers for water-based coatings. The object of this study was also to compare different fillers and additives in water-based barrier coatings. The coating performance can be controlled by a suitable choice of fillers. Folding of filled coatings destroys the barrier due to pinholes and cracks. Certain additives can improve the barrier performance of the coatings ; however, filler type and filler addition level are often the dominating factors as far as barrier properties are concerned.