Asif Elahi MANGAT, Lubos HES, Vladimir BAJZİK, Zuhaib AHMAD

INFLUENCE OF AIR FLOW DIRECTION ON THERMAL RESISTANCE AND WATER VAPOR PERMEABILITY OF RIB KNIT FABRICS

Thermal resistance and water vapor permeability play a critical role in thermo-physiological comfort. There are many factors, which can have influence on the thermal resistance and the water vapor permeability; one of them is airflow direction. This study is aimed to effort to identify the impact of airflow direction on thermal resistance and the water vapor permeability when forced convection heat transfer is used. 18 samples of rib knit fabrics made from the same polyester yarn were prepared. Rib direction on the surface of rib knit fabrics provides a channel for airflow. The thermal resistance and the water vapor permeability in two directions of ribs against the airflow, perpendicular and parallel, was measured. It was found that there is the impact of rib directions on the thermal resistance and on the water vapor permeability. Results indicates that the thermal resistance increases when the ribs lies parallel with the direction of airflow and the water vapor permeability has the tendency to decrease when the ribs lies parallel with the direction of airflow.

Keywords:

Thermal resistance water vapor permeability, air flow, physiological comfort, rib knit fabric,

PDF

___

1. Tarhan, M., and Sarisik, M, A Comparison Among Performance Characteristics of Various Denim Fading Processes, Textile Research Journal, 79, T301-T309, 2009.
2. Bogaty, H., Hollies, N.R.S., and Harris, M., Some Thermal Properties of Fabrics The Effect of Fiber Arrangement, Textile Research Journal, 27(6 ), T445-T449, 1957.
3. Mangat, M.M., Hes, H., and Bajzík, V., Thermal Resistance Models of Selected Fabrics in Wet State and Their Experimental Verification, Textile Res. Journal, 85(2), T200-T210, 2014.
4. Hes, L., Araujo, M. D., and Djulay, V. V., Effect of Mutual Bonding of Textile Layers on Thermal Insulation and Thermal Contact Properties of Fabric Assemblies, Textile Research Journal, 66( 4): T245-T250, 1996.
5. Hes, L., Thermal Comfort Properties of Textile Fabrics in Wet State, in Proc. Izmir Internat. Textile and Apparel Symposium,Cesme (Turkey), 2007.
6. Yoshihiroa, Y., Hiroakia, Y. and Hajimeb, M. , Effective thermal conductivity of plain weave fabric and its composite. Journal of Textile Engineering, 54(4), T111–T119, 2008.
7. Vigneswaran, C., Chandrasekaran, K., Senthilkumar. P., Effect of Thermal Conductivity Behavior of Jute/Cotton Blended Knitted Fabrics. J. of Industrial Textiles, 40, T49-T64, 2010.
8. Vallabh, R., Modeling Tortuosity in Fibrous Porous Media using Computational Fluid Dynamics, in Fiber and Polymer Science 2009, North Carolina State University, Raleigh, North Carolina. p. 246, 2009.
9. Kast, W., Klan, H., Heat Transfer by Free Convection: External Flows. VDI Heat Atlas VDI-Buch, T667-T672, 2010.
10. Bogusławska-Bączek, M., and Hes, L., Effective Water Vapour Permeability of Wet Wool Fabric and Blended Fabrics. Fibres Textile Eastern Europe, 97(1), T67-T71, 2013.
11. Haghi, A.K., Factors Affecting Water Vapor Transport Through Fibers. Journal Of Theoretical And Applied Mechanics, 30(4), T277-T309, 2003.
12. Hes, L., Boguslawska - Baczek M., Analysis and Experimental Determination of Effective Water Vapor Permeability of Wet Woven Fabrics. Journal of Textile and Apparel Technology and Management, 8(4): T1-T8, 2014.
13 Ucar, N., Yimaz, T., Thermal Properties of 1x1, 2x2, 3x3 Rib Knit Fabrics. Fibres and Textiles in Eastern Europe, 47(3), T34-T38, 2004.
14 Meloun, M., Militky, J. Statistical data analysis. A practical guide.Woodhead publishing India PVT LTD.p.773, 2011.