PVOH coatings to achieve high oxygen barrier on paper

摘要

In this study, the potential of using ethylene vinyl alcohol copolymers as aqueous coatings to achieve very good oil barriers and high oxygen barriers even at elevated relative humidity was investigated. It was shown that the presence of salts and plasticizers decreases the oxygen barrier level of PVOH/EVOH coatings. On the other hand, it was demonstrated that the addition of nano-clays enhances the oxygen barrier of PVOH/EVOH coating. Foam generation during make down as well as during application is a common problem when handling polyvinyl alcohol solutions. The hydrophobic/hydrophilic ratio of the defoamer is critical to maintaining good OTR and defoaming performance.