Experimental 3D fibre data for tissue papers applications

Abstract

Tissue paper consumption has been growing for the past years, with a forecasted increase in demand for premium products. Premium tissue paper products are obtained with a balance among softness, strength, and absorption properties, optimized for each kind of tissue paper. These properties are influenced by the three-dimensional structure, made from the spatial distribution of cellulose fibres. To our knowledge, the efforts made to date to improve the softness, strength and absorption properties have overlooked the 3D structure. There is an absence of 3D experimental data in the literature for the simultaneous characterization of individual eucalyptus fibres and the paper structure made from these fibres. The 2D fibre morphology determination, including fibre length and fibre width, was obtained by an image analysis method for pulp fibre suspensions, using the MorFi^Ⓡ equipment. The third fibre dimension, the fibre thickness morphology in the out-of-plane direction, was obtained using SEM images of non-pressed isotropic laboratory-made paper sheets. The effective fibre thickness morphology, consisting of the fibre wall and lumen, was measured in the paper structure, as this is precisely the key fibre parameter, influencing not only the structure-related properties, such as paper thickness, bulk, and porosity, but also the final end-use properties. The paper structures were produced using an ISO standard adapted method, for tissue paper structures, without pressing, with a basis weight range from 20 to 150 g/m². These data are important, among other possible uses, for paper property optimization and simulation studies with 3D fibre based simulators.

Keywords: 3D paper structure; Cellulose fibre; Effective fibre thickness; Eucalyptus fibre morphology; Tissue paper.

Fig. 1

Out-of-plane handsheets SEM images cross-section (z direction) were taken scanning the paper structure from left to right (x direction) with the same depth (Y direction). Measurements of 322 fibre thicknesses (Table 2) were performed in nine SEM images. The vectors used to measure each fibre thickness are visible in each SEM image. The cross-section (a) represents the measurements of 1–20 fibre’ thickness described in Table 2; (b) of 21–41; (c) of 42–73; (d) of 74–103; (e) of 104–138; (f) of 139–174; (g) of 175–219; (h) of 220–264; and (i) of 265–322.