Adding a Polymer Film Barrier Layer in the Press Forming Process of Paperboard Trays

The aim of this paper was to investigate the possibility to add a barrier layer in the press forming phase of paperboard trays by sealing a polymer film to a paperboard substrate. Plastic coating is often an important part of packages manufactured for food packaging. Traditionally the paperboards for food packaging are coated in the paper mill before the actual forming of the package. Experiments with coated and uncoated boards were made and the bonding and adhesion of materials was observed. The results indicate that adhesion between the board and the film can be achieved in the forming process. However there are challenges, such as lack of adhesion, air bubble formation and deformation of formed products. It is still shown that it is possible to achieve a bond between the paperboard and a barrier film, and to subsequently add a barrier layer from a separate film to paperboard trays in the forming process