Continuous inline fiber quality measurement and prediction of sheet quality potential, PaperCon 2010 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.

Increasing demands to produce uniform high quality products at minimal cost require better monitoring of the process. Many advanced control strategies are based on in-direct measurements. A more direct strategy, where the fiber morphology and the resulting sheet properties are linked directly to the process, has several advantages. This paper discusses a new device, an in-line fiber quality transmitter, which measures fiber morphological characteristics on a continuous basis at frequencies, which are 10-50 times higher than existing sampling devices. The high sampling rate allows us to control both short and long term variation. Physical models based on data from the quality transmitter are utilized to determine pulp drainage and important physical property characteristics. The laborious and time-consuming intermediate stages of hand sheet preparation are bypassed. The advanced software residing in the transmitter creates a “virtual hand sheet” and then proceeds to calculate important sheet quality parameters very rapidly. Engineering principles like FEM calculations are used. The calculated parameters include pulp freeness, drainage time, density, strength, as well as user defined properties. The paper is concluded with results from mill installations.