M. Rodríguez Ripoll, B. Scheichl, B. Jakab, F. Franek:
"Optimization of the Cleaning Performance of the Doctor Blade - Roller Tribosystem During Paper Production";
Talk: 2012 STLE 67th Annual Meeting & Exhibition, St. Louis, MO, USA; 2012-05-06 - 2012-05-10; in: "Conference Proceedings - 2012 STLE Annual Meeting & Exhibition", Society of Tribologists & Lubrication Engineers (STLE), (2012), Paper ID (ID) 1258481, Track / Category "Practical Lubrication Practices", 3 pages.
In the paper production, scraping (doctor) blades are placed in contact with rolls during wet pressing in order to keep the roll surface clean. The aim of this work is to determine the process parameters required for an optimum cleaning performance while simultaneously minimizing the wear of the doctor blade, thus increasing the blade lifetime and reducing energy consumption. So far, this process has been improved on a trial-and-error basis.
Our hypothesis is that the optimum conditions occur under "weak" hydrodynamic conditions. Friction force and wear can be substantially reduced, whereas the cleaning efficiency can be maintained as long as the film thickness is kept smaller than the minimum diameter of particles to be removed. Based on the equilibrium conditions at the blade tip between hydrodynamic and contact forces, a non-dimensional group involving the key parameters is obtained. This allows for a systematic improvement of the cleaning efficiency, which is verified experimentally.
Applied tribology: paper manufacturing, Components: paper machines, Hydrodynamics: hydrodynamic lubrication theory
http://publik.tuwien.ac.at/files/PubDat_207981.pdf