Optimization of coating with water-based barriers

For reasons of personal health and the environment, consumers are searching for “green” products. Packaging producers and consumers are seeing increased regulations set by authorities for packaging material and waste. Thus, interest in the development of renewable, sustainable fiber-based packaging products is growing. In recent years the paper industry has focused on finding substrates and the chemical suppliers have focused on developing different coating media to enhance properties. Sustainable paper and board barrier products are needed to create an alternative to the use of conventional packaging solutions containing plastics, perfluorocarbon, and wax. Typically, products with a water-based barrier coating are more expensive than conventional packaging solutions. Therefore, to make the new products with water-based barrier coatings cost competitive, the best achievable performance with the lowest coat weight is important so that production costs can be kept as low as possible. Results from pilot trials are presented that consider base stock (pretreated and non-pretreated), application methods by long- and short- (zero) dwell, and metering by rod and resilient tip. Laboratory evaluations of the coverage and barrier performance indicate the proper direction for obtaining a barrier.