Investigation of Factors Affecting Steambox Heating Effectiveness, 2001 Engineering / Finishing & Converting Conference Proceedings

T. F. Patterson--The work presented documents the third set of experiments conducted at IPST on factors effecting steambox heating effectiveness. The first set of experiments was directed at validating the usefulness of a new and unique piece of experimental equipment, the Steambox Comparator. The second set of experiments indicated that the wet sheet air permeability was a potential determinant factor in steambox heating efficiency. However, this second set of experiments was not designed to examine wet sheet air permeability. There was a fair amount of scatter in the data and only two fiber types were used. These shortcomings left some doubt as to the validity of the conclusion, and were the motivation for the third set of experiments. The hypothesis was based on the concept that the sheet structure (pore shape, size, interconnectedness, fiber physical structure, etc.) is the primary factor governing steam penetration into the sheet. Permeability is an indirect characterization of the sheet structure and sheet structure is affected by furnish, refining, pressing, and other sheet processing methods.

Sheets made from four different fiber types at two refining levels and three basis weights were used for this study: The primary conclusion from the experimental work was air permeability of the wet sheet was a determinant factor in steambox heating efficiency and that furnish, refining, and basis weight are not determinant factors in controlling the effectiveness of steam heating. Furnish, refining and basis weight are only important in that changing furnish or basis weight can alter the permeability of the sheet.