Brand owners and consumers continue to demand more sustainable options for single-use food packaging. Paper-based packaging offers an attractive solution because it is a renewable raw material that can be processed within existing recycling infrastructure. However, incumbent technologies for rendering paper impermeable to food-based substances like oil and grease, fatty acids, and hot/cold beverages can negatively impact its ability to fit into a circular economy. Traditionally, fluorocarbons are applied at low levels and low cost by treating the paper fibers in the pulp phase. This treatment strategy risks fluorocarbon release into the environment either as the paper biodegrades in landfills, or in the water discharge from the recycling process. An alternate strategy is to apply a physical barrier such as a polymeric barrier coating, most commonly via extrusion coating in which solid polymer pellets are heated, extruded into a molten film, and applied to paper. However, the extrusion process requires thick films to achieve suitable mechanical adhesion to the paper substrate and to provide a continuous, defect-free film, which can lead to difficulties recycling the coated paper articles.

The innovative RHOBARR(TM) line of high-performance waterborne coating products for recyclable paper-based packaging offers award-winning technologies that provide barrier against oil and grease, fatty acids and mineral oil, and hot/cold liquids, along with additional packaging properties such as heat seal, film flexibility, and block resistance. RHOBARR(TM) Barrier Dispersions are applied to paper/board as an aqueous dispersion, then dried to form ultra-thin (95% fiber recovery rate in internal testing (Voluntary Standard for Repulpability from the Fibre Box Association (FBA)), (iii) internal cradle-to-grave life cycle analyses validating significant improvements over extrusion-coated paper, and iv) external validation of ~30% bio-renewable carbon content (Beta Labs according to ASTM-D6866).

Harnessing years of manufacturing, synthesis, and formulation expertise, Dow scientists have developed a product line comprised of the following offerings, with further products in the development pipeline:

• RHOBARR(TM) 320/325 Barrier Dispersion: hot/cold liquid barrier, heat seal
• RHOBARR(TM) 214 Emulsion: mineral oil/fatty acid barrier, heat seal, low coefficient of friction
• RHOBARR(TM) 135 Emulsion: hot oil/grease resistance, microwave- and oven-use (ISEGA certified)

These RHOBARR(TM) Barrier Technologies are protected by a robust portfolio of intellectual property covering process technology, product composition, and application expertise. RHOBARR(TM) Emulsions are produced via emulsion polymerization or a proprietary mechanical dispersion process (BLUEWAVE(TM) Technology). RHOBARR(TM) Barrier Dispersions continue to gain industry share globally, with end uses in paper beverage cups, microwavable molded fiber bowls, and sandwich wraps.