The Benefits of Water-Based Barrier Coatings for Recycling

Wednesday, 10 March 2021


Recycling at Paper Mills

For paper, recycling has a higher priority over composting in the Sustainability Pyramid and the Circular Economy because it allows paper‘s valuable fibers to be reclaimed for reuse. However, plastic film—like polyester (PE), polypropylene (PP), polyethylene (PET), or others—when laminated to paper, creates many recycling issues for paper mills. Film decreases the capacity of a paper mill‘s pulper because it takes more time for the paper to repulp due to the plastic film protecting the fibers from water during the recycling process.

Paper Coating, Drying, and Film Forming Acrylic particles dispersed in water are applied to the surface of the paper. As the water evaporates, the particles pack more closely together. In the pulper, as water breaks the fiber bonds, the polymers follow the fiber and filler to form a new paper web. The tight packing causes the particles to deform. Polymer chains entangle across boundaries, and the particles coalesce to form a barrier film. Repulping What Happens to Polymer Coatings in a Paper Mill

Polymer coatings are now being used on paper to replace plastic film, providing functionality and improving recyclability with easier processing, less plastic waste, and less contamination. Oliver Kalmes, Michelman‘s Territory Manager for Printing & Packaging, EMEA, recently published an article that further explains polymer coatings‘ advantages and what happens to them in a paper mill.