Through Air Drying of Tissue and Towel, 1997 Engineering Conference Proceedings

A computer model simulating the sheet drying part of through air drying of tissue and towel has been developed. It is based on theoretical considerations and experimental data. Results indicate that under the low air flow, temperature conditions studied, the sheet temperature quickly warms-up to the saturation temperature, and remains constant for rather a long time before beginning to rise at the end. The sheet drying rate, however, primarily comprises of an increasing rate period and a falling rate period. The constant drying rate period, if any, is quite small. Empirical relationships for heat and mass transfer coefficients show that a simple, single relationship covering a wide range of tissue and towel through drying conditions is not adequate. However, several empirical relationships, each covering a narrow range of process conditions, are found to be more accurate. The analysis indicates that experimental data representing commercial operating conditions are critical in achieving an over-all system simulation.