Cellulose nanofibril coatings with low coat-weight and improved barrier performance for hybrid molded fiber substrates
Year: 2026
Type: article
Abstract: This study aimed to minimize the nominal coat weight of cellulose nanofibrils (CNFs) while improving the oil-and-grease barrier of a newly developed hybrid molded fiber (HMF) system that combines CNFs, bleached kraft pulp (BKP), and wood flour (WF) for a material-efficient, per- and polyfluoroalkyl substances (PFAS)-free solution. Two drying methods (oven drying and hot pressing) across three temperature settings (80 °C, 120 °C, and 160 °C) were evaluated for coatings ranging from 1 to 5 g/m² A 3 g/m² CNF coating reduced oil absorption by 72-78% compared to uncoated samples, while a 5 g/m² coating achieved a Kit value of 9-11, resulting in a 92% reduction in oil absorption. The CNF coating alone provided limited water resistance to the substrate, with no significant changes in thickness swelling. However, the introduction of 1% alkyl ketene dimer (AKD) resulted in a substantial reduction in both the substrate Cobb value and thickness swelling. Microwave heating tests conducted for up to 90 s demonstrated that a 5 g/m² CNF coating effectively prevented visible oil penetration. Overall, applying a CNF coating at 5 g/m² significantly enhanced resistance to oil and grease, with no visible coating failure observed during microwave heating for up to 90 s under the tested conditions. CNF-coated containers with low coating weights made from HMF substrates offer a promising PFAS-free oil barrier approach for food packaging.
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,790
Award: G9000385825
OpenAlex ID: W7214076012