Automated segmentation of wood fibres in micro‐CT images of paper

Abstract

A novel algorithm has been developed and validated to isolate individual papermaking fibres in μCT images of paper handsheets as a first step to characterize the structure of paper. The three step fibre segmentation algorithm segments the papermaking fibres by (i) tracking the hollow inside the fibres via a modified connected component methodology, (ii) extracting the fibre walls using a distance transform and (iii) labeling the fibres through collapsed sections by a final refinement step. Further, post processing algorithms have been developed to calculate the length and coarseness of the segmented fibres. The Fibre Segmentation algorithm is the first ever reported method for the automated and robust segmentation of the tortuous 3D morphology of papermaking fibres within microstructural images of paper handsheets. The method is not limited to papermaking fibres, but can be applied to any material consisting of tortuous and hollow fibres.2

Imbibition with swelling: Capillary rise in thin deformable porous media

“…If > 0, we solve (26) as an elliptic problem for σ(y, t) at each time step, together with a hyperbolic evolution equation for H(y, t) (or φ(y, t)) and a simple ODE for (t). The boundary and initial conditions are given in (27) and (28). We use a standard second-order finite difference discretization in space, and a fourth-order Runge-Kutta scheme to evolve in time.…”

Moulded pulp products manufacturing with thermoforming

“…Table shows an overview of the scanning parameters used in this work. The beam absorption of paper is known to be very weak, and thus, usually low voltage is applied . On the contrary, the current determines the contrast of the workpiece, and its value was set relatively high, ie, 2 A.…”

“…The beam absorption of paper is known to be very weak, and thus, usually low voltage is applied. 23,25,29,37 On the contrary, the current determines the contrast of the workpiece, and its value was set relatively high, ie, 2 A. The target was selected to suit the low-voltage X-ray source, and the popular material for this purpose is molybdenum, as reported in previous studies.…”

“…Despite the advantages in terms of resolution of acquisition of synchrotron CT, conventional CT set‐up is widely used and constantly improved. It was in fact used among others by Wernersson et al, Sharma et al, Miettinen et al, and Saxena et al…”

“…[22][23][24][25][26][27] Despite the advantages in terms of resolution of acquisition of synchrotron CT, conventional CT set-up is widely used and constantly improved. It was in fact used among others by Wernersson et al, 28 Sharma et al, 29 Miettinen et al, 30 and Saxena et al 19 With the purpose of setting a step towards in the standardization of design and testing practices of eco-friendly packaging, this work focused on the characterization of the thermoforming process of moulded pulp products and their characteristics. In particular, this work composes of three investigations.…”