Improving Physical Properties and Printability of Fruit Packaging Kraft Liner with Mineral and Nanographene Coatings

Abstract

Biological nanomaterials such as nanographene and fluorite have garnered the attention for the production of diverse products, particularly food packaging, owing to their biocompatibility and biodegradability. The objective of this study was to prepare a coated paperboard sheet utilizing nanomaterials and mineral compounds to enhance the physical characteristics and printability of the brown kraft liner paper. In this investigation, a 120 g/m² brown kraft liner was employed, in conjunction with varying quantities of nanographene, zein protein, and fluorite, combined with internal resin for the coating process. The physical properties were examined. The samples were treated in standard conditions of 20 °C and 65% relative humidity. The results revealed that the coating led to an increase in yellowness, opacity, glossiness, optical density, and resistance to air permeation compared to the control sample. Notably, the air resistance of the graphene-coated sample was about 5350 seconds. The roughness increased by 9.7 µm with the use of fluorite. Furthermore, a noticeable increase in opacity and glossiness was observed in the coated samples. The adhesion of the coated layer and flexo ink was also excellent, so that it remained intact on the paper surface.