Abstract
An orifice flowmeter was used to measure the extensional viscosity of several non-pigmented fluids and paper coating colors containing calcium carbonate as pigment in the context of a jet coating application. The orifice flowmeter was first calibrated in terms of a dimensionless Euler number versus Reynolds number curve with Newtonian fluids. The calibration curve was then used to determine the apparent extensional viscosity of coating colors. In the strain rate range investigated, all the fluids were found to exhibit strain-thinning and the Trouton ratio of the coating colors was in the range 5 to 20. Jet coating tests were also carried out in order to evaluate the effect of the extensional viscosity on the jet performance. The extensional viscosity was shown to be a key parameter determining the configuration of the downstream meniscus in the web contact region.
REFERENCES
[1] Walter JC: The Coating Process, TAPPI Press, Atlanta (1993).Search in Google Scholar
[2] Russel NB, Saville DA, Schowalter WR: Colloidal Dispersions, Cambridge University Press, Cambridge (1989).10.1017/CBO9780511608810Search in Google Scholar
[3] Hiorns AG, Coggon L, Windebank M: Evaluation of the Jet Fountain Applicator in Blade Coating Systems for LWC Rotogravure, Coating Conference, TAPPI Proceedings (1999) 111-116.Search in Google Scholar
[4] Roberts J, Lerche LH, Bauer W: How’s Life with Free Jet?, Pulp Paper Europe 4(1999) 25-26.Search in Google Scholar
[5] Macosko CW: Rheology: Principles, Measurements, and Applications, VCH Publishers, New York (1994).Search in Google Scholar
[6] Cogswell FN: Converging Flow of Polymer Melts in Extrusion Dies, Polym. Eng. Sci. 12 (1972) 64-73.Search in Google Scholar
[7] Binding DM: An Approximate Analysis for Contraction and Converging Flows, J. of Non- Newton. Fluid Mech. 27(1988) 173-189.Search in Google Scholar
[8] Isaksson P, Rigdahl M, Flink P, Forsberg S: Aspects of the Elongational Flow Behaviour of Coating Colours, J. Pulp Pap. Sci. 24 (1998) 204-205.Search in Google Scholar
[9] Della Valle D, Tanguy PA, Carreau PJ: Characterization of the Extensional Properties of Complex Fluids Using an Orifice Flowmeter, J. Non-Newton. Fluid Mech. 94 (2000) 1-13.Search in Google Scholar
[10] O’Brien VT, MacKay ME: Shear and Elongational Flow Properties of Kaolin Suspensions, J. Rheol. 46 (2002) 557-571.Search in Google Scholar
[11] Ascanio G, Carreau PJ, Brito-De La Fuente E, Tanguy PA: Orifice Flowmeter for Measuring Extensional Rheological Properties, Can. J. Chem. Eng. 80 (2002) 1189-1196.Search in Google Scholar
[12] Metzner AB, Otto RE: Agitation of Non-Newtonian Fluids, AIChE J. 3(1957) 3-10.10.1002/aic.690030103Search in Google Scholar
[13] Toivakka M, Eklund D: Prediction of Suspension Rheology Through Particle Motion Simulation, Advanced Coating Fundamental Symposium, TAPPI Proceedings (1995) 161-177.Search in Google Scholar
[14] Carreau PJ, Lavoie PA: Rheology of Coating Colors: A Rheologist Point of View, Advanced Coating Fundamental Symposium, TAPPI Proceedings (1993) 1-12.Search in Google Scholar
[15] Steffe JF: Rheological Methods in Food Process Engineering, Freeman Press, Michigan, (1996).Search in Google Scholar
[16] Ascanio G, Carreau PJ, Réglat O, Tanguy PA: Extensional Properties of Coating Colors at High Strain Rates in Relation with Misting, Advanced Coating Fundamentals Symposium, TAPPI Proceedings (2003) 5-8.Search in Google Scholar
[17] Arzate A, Ascanio G, Carreau PJ, Tanguy PA: Extensional Properties of Coating Colors at High Strain Rates, ASME International Mechanical Engineering Congress and Exposition (2003) paper IMECE03-43529.10.1115/IMECE2003-43529Search in Google Scholar
© 2004 A. Arzate et al., published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
