Mineral Oil Findings in Recycled Fibre Food Packaging
Recycled paperboard packaging requires verified functional barriers and HPLC-GC-FID test dossiers to prevent gas-phase MOSH and MOAH food contamination.
Aqueous Barrier Dispersion
Liquid Coating
Protective layers for paper packaging are increasingly formed by applying a water based polymer suspension to the surface of the board. An aqueous barrier dispersion utilizes microscopic plastic particles or natural waxes held in a liquid state to create a continuous film upon drying. This method avoids the use of plastic laminates, making the finished carton easier to pulp and recycle in standard paper mills.
The chemistry often involves acrylic or styrene copolymers that are engineered to resist water and grease.
Film Formation
Evaporation of the water carrier causes the polymer particles to coalesce into a pinhole free barrier. The aqueous barrier dispersion must be applied at a specific coat weight to ensure that the entire surface of the cellulose fibres is covered without leaving gaps. Heat is applied during the drying stage to accelerate the fusion of the polymers into a solid matrix.
Modern Performance
Resistance to mineral oil migration is a common requirement for these coatings when used with recycled fibre stocks. They provide a functional barrier that prevents hydrocarbons from the paper from entering the food while maintaining the breathability of the package. Because the material is applied as a liquid, it can be integrated into existing printing or coating lines with minimal structural changes.