Combination of MFC wet lamination and chromatogeny grafting processes to produce all cellulose packaging materials

Abstract

The packaging industry is undergoing a major turn in its history looking for biobased, recyclable and biodegradable alternatives to petrobased products. Cellulose based materials such as paper and board can be a good solution, however, they present poor barrier properties, which are mandatory for packaging applications. In this study, all cellulose packaging with good barrier properties to grease, oxygen, water and water vapour were produced combining two innovative technologies: the wet lamination of microfibrillated cellulose (MFC) and the chromatogeny grafting. First, a thin layer of MFC (10 to 25 g/m²) was applied on a board without the use of glue in one pass. The influence of the MFC grade on the minimum MFC coat-weight required to develop grease barrier properties was investigated. Secondly, the MFC wet laminated board was grafted by chromatogeny at pilot scale. The MFC covered produced samples present excellent grease barrier properties with an oil absorption lower than 2 g/m² after 1800s (Cobb oil 1800s), a kit test of 12 and very good oxygen barrier properties. The chromatogeny grafting of fatty acids on the MFC hydroxyl groups confers barrier properties to water and water vapour to the MFC wet laminated board with a water vapour transmission rate around 36 g/(m².d). Finally, the mechanical properties of the samples and the adhesion of the MFC layer on the board were evaluated.