PAPER making!
FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ®
Volume 10, Number 2, 2024
Simulation of Sheet Molding during Through Air Drying of Tissue Paper within a Papermaking Framework
K. REZK & B. SJÖSTRAND
A way to improve product performance of tissue grade paper products is to replace the press section with a Through Air Drying (TAD) section which is a technique where paper sheets are moulded into a structured fabric by vacuum boxes and transferred over one or more TAD cylinders with steam heated displacement drying. The process of sheet molding is modelled with Comsol Multiphysics where the computational model is setup with a 2-dimensional representation of the paper sheet. The tissue sample with randomly distributed fibre positions is generated using a MATLAB script written in the Livelink interface with Comsol. The process is simulated with the Moisture Flow multiphysics interface. The comprising physical modules are the Laminar Flow and the Moisture Transport in Air modules. Respectively, these modules calculate the velocity and pressure field of the moist air as well as the relative humidity, which is a rewrite of the concentration of water in air. The fibres in the sheet are modelled as porous media where the fibres contain both moist air and liquid water in equilibrium. In this paper, a basis weight at roughly 20 g/m 2 is simulated and compared to laboratory data. The aim of the model is to estimate solid content in the paper sheet over vacuum time as well as energy demand and required airflow through the structure. Contact information: Pro2BE, the research environment for Processes and products for a circular forest-based bioeconomy, Department of engineering and chemical sciences, Karlstad University, Karlstad, Sweden.
COMSOL Conference 2023, Munich Open Source
The Paper Industry Technical Association (PITA) is an independent organisation which operates for the general benefit of its members – both individual and corporate – dedicated to promoting and improving the technical and scientific knowledge of those working in the UK pulp and paper industry. Formed in 1960, it serves the Industry, both manufacturers and suppliers, by providing a forum for members to meet and network; it organises visits, conferences and training seminars that cover all aspects of papermaking science. It also publishes the prestigious journal Paper Technology International ® and the PITA Annual Review , both sent free to members, and a range of other technical publications which include conference proceedings and the acclaimed Essential Guide to Aqueous Coating .
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Article 2 – Simulation of TAD
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