Frictional Impulse in Mechanical Wood Grinding, 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.



A frictional impulse was tested in wood grinding by employment of data produced on a laboratory scale implying that grindstone and wood quality may be considered unchanged. It means that the grinding parameters can be studied sufficiently, also because any effects of the grindstone curvature can practically be eliminated, since the grinding opening is small.

The frictional impulse is defined as a ratio between the compression force and the peripheral grindstone speed. Both factors are basically independently selectable, and they affect the wood advance rate (fiberising speed) and drag/shear force (fibrillation degree and coarse fiber content), which hence are dependent factors.

Obtained results confirm that the frictional impulse better than compression force described the grinding in terms of wood advance rate and drag force. Their linear correlation coefficients at peripheral speeds of 15-30 m/s were 0.98-0.99. In a later study the correlation coefficients were 0.94-0.99 at 30 m/s. It seems that grinding may well be described by the frictional impulse proposed.