Increased recyclability of wet strengthened liquid packaging board, through synergetic effects of combining CMC and PAE – A case study in full scale

There is an ever-increasing demand for renewable, recyclable and biodegradable packaging solutions,from consumers, producers of goods, and producers ofpackaging materials. Closing the material loop andincreasing recyclability of fiber-based package materials isone of the keys to move forward towards a more sustainablefuture. While the recyclability rates of fiber-based packagingare high, packaging boards with high wet-strength can poseproblems due to problems with repulping. This manuscriptinvestigated the possibilities to reduce the use of polyamideepichlorohydrin resins (PAE) by supporting the processsystem with carboxy-methylated cellulose (CMC) throughmachine trials in mill scale production. The focus of theinvestigation was on the wet-strength of the board productand the repulpability value. The results given from thefull-scale trial were positive, indicating a potential in usingCMC while reducing the PAE addition. The results showedthat wet tear strength and wet tensile strength of the boardwere maintained, while higher repulpability rates weregiven, encouraging better recyclability of the board material. This will be beneficial to the environment both withlower use of non-renewable chemicals and possibilities forhigher degrees of recycling of the board products.