Repulpability and Biodegradability of Paper-based Packaging Products with Water-borne Barrier Coatings: A Review

Abstract

Published findings are reviewed related to the recovery and recycling, as well as the biodegradability, of single-use food packaging materials that include waterborne barrier coating layers. Such layers can replace petroleum-based plastics, such as polyethylene, which tend to build up in the environment and contribute to microplastics issues. Barrier layers, of either type, can block the transport of oxygen, water vapor, liquid water, grease, contaminants, and flavors in and out of such packaging systems.  Key concerns include whether such layers can be readily dispersed in water, thereby allowing the packaging material to be used again in subsequent generations of recycled paper products. The process efficiency, including the yield of recovered materials, is also of concern. Because single-use food packaging products, in most regions, are not yet routinely routed to paper recycling, this review also considers findings related to biodegradability and compostability of waterborne barrier layers. Based on the reported findings, there are numerous waterborne formulations that can meet practical needs in terms of biodegradability and repulpability, leading to relatively high yields in paper recycling operations. Chemical components of future waterborne coating formulations need to be considered on a case-by-case basis regarding their contributions to toxicity, compostability, general biodegradability, and circular systems of recovery and reuse.