Power Threshold Effect in Grinding-An Expression of Elastic Work?, 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.



Mechanical pulping processes, including pressurized groundwood (PGW) consume much more electrical energy than would be adequate for production of new fiber surfaces. Many investigations have shown that the major part of this energy is consumed by elastic deformations of wood.

This paper discusses the so-called power threshold effect (PTE) in the grinding process. PTE is herein defined as the grinding power required to initiate and maintain the defibration process. It is assumed that the PTE might be associated with energy that is spent in elastic deformation of the wood related to the grits. These studies were conducted with a pilot grinder in PGW-S conditions. The PTE was defined in an experiment in which the grinding power was gradually increased until the fiber production started. The pulps were also analyzed for CSF and tensile index.