Paper barrier layers

Layers of functional additives on the paper provide a barrier against foreign substances and thus prevent them from penetrating or passing through. Paper barrier layers are of particular importance in the food industry, as volatile components must not be allowed to escape from or enter the packaging (e.g. to preserve an aroma).

A barrier layer is achieved by a minimal plastic-based coating through the targeted addition of additives or fillers. In the model, the barrier layer can be represented as a close-meshed net that is laid over the fibre structure of the paper on the surface. The trend is towards water-based dispensions and biobased and biodegradable coatings. The curtain coater technology with its constant jet over the entire working width has established itself as the process.