Lignin-containing micro/nanofibrillated cellulose to strengthen recycled fibers for lightweight sustainable packaging solutions

Abstract

As e-commerce drives the packaging growth, consumers are pushing for more sustainable packaging solutions. Considering the current societal needs, we have been able to engineer a new pathway for sustainable packaging solutions by developing lignin-containing micro- and nano-fibrillated cellulosic (LMNFCs) materials to strengthen the recycled fibers. LMNFCs from unbleached softwood pulp containing 14.4% lignin at high and low fibrillation levels were produced. Packaging papers from recycled old-corrugated containers were strengthened with LMNFCs with varying addition levels of 1 wt% to 3 wt% at two basis weights. The results show 2 wt% addition of LMNFC can enhance strength at low levels of fibrillation, and that basis weight can be reduced by 16.7%, from 150 gsm to 125 gsm, while maintaining a burst strength of 49-53 lbf. Reduction in basis weight and high lignin content of LMNFC also enhanced dewatering during sheet formation with the lowest increase in drainage time, 9%, relative to the 150 gsm with no LMNFC. The techno-economic analysis supports the feasibility of using LMNFC to produce lightweight and sustainable packaging materials at industrial scale with an 8% reduction in fiber cost.