Recyclable wax-coated paperboard using H2-AKD modified paraflex 4797A coatings

Overview

This technology addresses a long-standing challenge in paper recycling: wax-coated paperboard is traditionally difficult to repulp, limiting its recyclability and contributing to landfill waste. The solution combines recycled paperboard substrates with coatings based on Paraflex 4797A wax modified with H2-AKD, an alkyl ketene dimer sizing agent. By blending H2-AKD into the wax coating at varying concentrations, the coated paperboard can be repulped more easily across a broad pH and temperature range, enabling circular use of fiber-based packaging materials.

The approach is particularly relevant for packaging applications where moisture or grease resistance is required, such as food service, agricultural product packaging, and industrial wrapping. By improving the recyclability of coated paperboard, this technology supports sustainability goals and regulatory pressures around packaging waste reduction.

Technical specifications

Key features:

• Substrate produced from recycled paper pulp on a pilot paper machine at 50 °C and pH 7.5
• Coating system based on Paraflex 4797A wax modified with H2-AKD at concentrations of 5, 10, 15, 25, 50, and 100 percent
• Curing protocol of 85 °C for 30 minutes to set the coating
• Improved repulpability across the full range of tested pH and temperature conditions
• 100 percent H2-AKD coatings repulp the fastest of all formulations tested
• Repulpability of H2-AKD and H2-AKD/wax blends improves as pH increases from 5 to 12

Technology readiness level

The technology has been validated at pilot scale using a pilot paper machine and controlled coating and curing procedures. Repulpability testing has been performed across multiple H2-AKD concentrations and pH conditions, confirming that the addition of H2-AKD to Paraflex 4797A wax improves recyclability over the entire pH and temperature range tested. Further work is needed to scale production, evaluate long-term coating performance in real packaging environments, and validate compatibility with industrial repulping equipment and end-use applications.