Analysis of Surface Roughness Characteristics of Paper Coated with Nanocellulose and Oxidized Starch according to Measurement Method

Cellulose is one of the constituents of plants and is an environmentally friendly resource with a semi-permanent supply and high biodegradability. CNF from cellulose is useful for various purposes. CNF has high aspect ratio and high specific surface area and it is excellent in mechanical properties and thermal stability, and it has shear-thinning flow characteristics. When CNF is coated on paper, it provides high barrier property with excellent network forming ability. The surface roughness of the coated paper is one of the characteristics that determine the quality of coated paper and printing. The surface roughness is measured by the stylus profiling, the air leak, and the optical image analysis methods. Each analysis method has certain characteristics, so surface roughness of coated paper was analyzed by those three methods and results were compared. After mixed coating of CNF and oxidized starch, the degree of roughness was increased in the probe method and the air leakage method when the coating weight and the amount of CNF were increased. The degree of roughness which is measured by Optitopo decreased when the mixed solution was coated. Because the range of roughness measured by each measurement method is different, it might give different tendencies. © 2019 Korean Technical Assoc. of the Pulp and Paper Industry. All rights reserved.