Barrier Coating of Fruit-packing Tissue Paper Using Nanofibrillated Cellulose and a Water-Repellent Agent

Abstract

An environmentally friendly barrier-coating strategy  was studied for fruit-packing tissue paper intended for use in fruit protection bags under humid agricultural conditions. Because tissue paper has high porosity and hydrophilic characteristics, its practical use is limited by low mechanical strength, high air permeability, and poor water resistance. Three coating systems were evaluated using nanofibrillated cellulose (NFC) and a water-based acrylic water-repellent: tissue paper coated twice with NFC, tissue paper coated twice with the acrylic agent, and tissue paper sequentially coated with one NFC layer followed by one acrylic top coating. Double NFC coating increased tensile strength from 2.96 to 4.34 kN/m and improved Gurley air resistance from 34.3 to 114.6 s through pore filling and enhanced inter-fiber bonding. The double acrylic coating provided a water-repellency level of 8 but had limited effects on tensile strength and air resistance. The multilayer coating combined the advantages of both materials, maintaining improved tensile strength, reduced air permeability, and strong water repellency. FE-SEM observations confirmed reduced pore openness after NFC application and continuous film formation after acrylic top coating. These results indicate that sequential coating with NFC and an acrylic water-repellent provides an effective route for improving the barrier performance of tissue paper for fruit protection applications.