Author_Institution :
Dept. of Chem. Eng. & Appl. Chem., Toronto Univ., Ont., Canada
Abstract :
Paper is made by a continuous high-speed filtration drainage of an aqueous suspension of fibers. This paper presents a new approach to the controllable simulation of paper forming, using artificial neural network methods. The model incorporates dynamics of the forming process, like turbulence, drainage speed, and preferential drainage through earlier less-dense regions and fiber properties, like propensity to clump, or “flocculate,” fiber flexibility, and concentration of fibers in the suspension. Results for monofiber layer structures are described, showing effects of turbulence and its decay during drainage in causing clumping, or “flocculation.” The commercial process has, as one of its main goals, the reduction to tolerable levels of the nonuniformity in mass distribution resulting from flocculation. The new model yields data corresponding to that obtainable along arbitrary scanning lines in planar stochastic fibrous structures, providing profiles, variances, histograms of local areal density, and histograms of local free-fiber lengths. These results closely resemble experimental data from commercial paper samples obtained from radiographic or optical transmission images subjected to image analysis
Keywords :
digital simulation; fibres; flocculation; image processing; neural nets; paper industry; production engineering computing; simulation; turbulence; aqueous suspension; clump; continuous high-speed filtration drainage; controllable simulation; drainage speed; fiber flexibility; fiber flocculation; forming process dynamics; image analysis; local areal density; monofiber layer structures; neural network model; optical transmission images; paper-forming process; planar stochastic fibrous structures; preferential drainage; radiographic images; turbulence; Artificial neural networks; Chemical engineering; Chemistry; Fabrics; Filtration; Histograms; Jacobian matrices; Neural networks; Pulp and paper industry; Stochastic processes;