Moisture-Induced Surface Roughness in TMP, 2007 International Mechanical Pulping Conference

Please Note: This document will be available in PDF format in the "My Electronic Documents" link on the home page once your order has been completed. Please make sure you have the latest version of Acrobat Reader. Click on the Acrobat Reader icon to check for the latest version, it’s FREE. To print a hardcopy of a PDF file correctly you must have a postscript printer. If you are not sure if your printer is a postscript printer please refer to your owner’s manual.



Favourable surface properties can be attained in softwood thermomechanical pulp (TMP) based sheets, if most of the thick walled long fibres are collapsed. Provided this can be done, a large amount of TMP can be used in high quality wood containing papers, i.e., LWC or SC grades, without serious printability problems. It is known that the degree of fibre collapse during refining under standard TMP conditions is strongly related to the fibre wall thickness. However, the thickness of the thickest fibre walls cannot easily be changed by peeling actions in refining under standard TMP conditions in the CSF range of interest for news and magazine grades. Therefore, refining conditions obviously must be changed to enable the proper collapse of these fibres. Earlier studies (Norgrenand Höglund, IMPC 2003 and 2005) have demonstrated that thick walled fibres are more easily collapsed by reject refining after preheating to temperatures well above the softening temperature of lignin, i.e., high temperature conditions, than under standard conditions.