Document Type : Research Paper

Author

Prof., Wood Science and Technology Department, Civil Engineering Faculty, Shahid Rajaei Teacher Training University, Tehran, Iran

Abstract

Abstract

In this study, alumina nanoparticles was added to clear varnishes (Sealer, clear, semi-polyester and polyurethane), and changes in adhesion strength on wood specimens of Walnut (Juglans Regia) and spruce (Picea Spp) were studied. The experimental samples were prepared from defect-free woods with size of 300×100×10 mm and dried to 8 % moisture content in air drying and Killen drying, respectively. The samples surfaces finished and the clear varnishes applied on samples surfaces using pneumatic spry gun and the adhesion strength test was done on samples. The result of this study showed that the highest adhesion strength was observed in polyurethane varnishes with 6% alumina nanoparticles in walnut wood, and the lowest adhesion strength observed in cellulosic varnishes (sealer and clear) with 0% nanoparticles in spruce wood. It can be concluded that with the control of nano alumina percentage in varnishes in a defined level, the adhesion strength of the clear varnishes increased. Also, with improvement of varnishes’ adhesion strength on wood surface, the varnishes durability increased, consequently.

Keywords

-Annual Book of ASTM Standard, D 3359. 1997. Standard Test Methods for Measuring Adhesion by Tape Test.
-Annual Book of ASTM Standard, D 3924. 1996. Standard Specification for Standard Environment in Conditioning and Testing Stain Varnish, Lacquer and Related Materials.
-Bagheri, h., 2013. The effect of wood primer finishing on bounding strength of the coats in furniture and wood products, Master of science thesis, Shahid rajaei teacher training university.
-Budakci, M. 2003. Design and Production of a New Adhesion Testing Device and Its Utilization with Testing of Wood Varnishes, Ph.D. Thesis, Department of Furniture and Decoration, Gazi University, Ankara.
-Chin, J., E. Byrd and J. Martin, and T. Nguyen. 2005. Validation of the Reciprocity Law for Coating Photo degradation, J. Coat. Technol. Res., 2 (7):499–508.
-Ghofrani, M., Khojasteh Khosro S., 2013. The effect of surface preparing with ziokosyle nano particles on bounding strength of clear varnishes.  National Conference of environmental science engineering and development. Bahman17,
-Ghofrani, M., Khojasteh Khosro, S., 2013. Effect of wood surface defatting on bounding strength of clear varnishes. Journal of science and technology of paint. 1436-2013-02-03  JCST.
-Ghofrani, M., Mirkhandouzi, F. Z., & Ashori, A. 2016b. Effects of extractives removal on the performance of clear varnish coatings on boards. Journal of Composite Materials, 50(21), 3019-3024.
-Ghofrani, M., Samadi, E. and Khojasteh Khosro, S., 2016a. Heat treatment of wood and the investigation of its effect on surface wettability and adhesion strength of coating. Iranian Journal of Wood and Paper Science Research, 31(2): 362-373.
-Gholamian, h., tarmian,.a., 2010. Measuring gas permeability factor and liquid in populous nigra coated with clear varnishes and nanoparticles. Journal of Iran forest and wood products.
-Gholamian, h., tarmian,.a., doust hoseini, k., azadfallah, m., 2011. The effect of clear varnishes and zayokosyle and nanokofyle nano particles on surface tension and water absorption in poplar wood. Journal of wood and paper science and research (1)2: 26-16.
-Kashani, A., and S. Moradian. 2010. Effects of nano alumina on some physical and mechanical properties of an acrylic water based clear coat. J. Color Sci. Tech. 4, 169-174.
-Kaygin, B. and Akgun, E. 2008. Comparison of conventional varnishes with nanolake UV varnish with respect to hardness and adhesion durability, Int. J. Mol. Sci, 9: 476-485.
-Kaygin, B. and Akgun, E. 2009. A nano-technological product: An innovative varnish type for wooden surfaces, Scientific Research and Essays, 4 (1): 1-7.
-Kaygin, B., Akgun E. 2008. Comparison of conventional varnishes with nanolake UV varnish with respect to hardness and adhesion durability. Int. J. Mol. Sci. 9(2008), 476-485.
-Khojasteh Khosro, S., Ghofrani, M. and Ganjaee Sari, M., 2015. The effect of adding zinc oxide nanoparticles on color change and adhesion strength of polyurethane coating on wood surface. Iranian Journal of Wood and Paper Science Research, 30(4): 690-704.
-Kureli, I. 1996. Search on Application Possibility of Chip-wood and Fiber Plates over Wet Surface, Ph.D. Thesis, Department of Furniture and Decoration, Gazi University, Ankara.
-Maanavi, gh., ghofrani, m., mirshokraei, a., 2012. The effect of type, moisture content and type of coating on bounding strength of adhesive of clear varnishes used in furniture industry. Journal of wood and paper science and research. (2)27: 753-743.
-Nazerian, m., 2012. Preservative coatings, ornamental wood and wood products, Jehad daneshgahi publication. Tehran. Iran.
-Ozdemir, T., S. Hiziroglu. 2007. Evaluation of surface quality and adhesion strength of treated solid wood, J. Mat. Processing Technol. 186: 311-314
-Sjostrom, E., 1993. Wood Chemistry Fundamentals and Applications; Academic Press: San Diego, p 293.
-Sonmez A., M.  Budakci and M. Bayram. 2009. Effect of wood moisture content on adhesion of varnish coatings, Scientific Research and Essay. 4(12): 1437-1432.
-Sonmez, A., M.  Budakci and H. Pelit. 2011, THE effect of the moisture content of wood on the layer performance of water-borne varnishes, BioResources 6(3): 3178-3166.
-Stamm, A., J. Millett. 1940. The interial surface of cellulosic materiales Persented at the seventeenth colloid symposium, helt at ann arber, Michigan, 843-45.
-Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers, Annual Book of ASTM Standard, ASTM Standard, D4541, 2002.
-Wood - Sampling methods and general requirements for physical and mechanical tests, TSE: Ankara, Turkey, TS- 2470, 1976.
-Xie,Y., A. Krause, H. Militz and C. Mai. 2006. Coating performance of finishes on wood modified with an  N- methylol compound. Progress in Organic Coatings 57, 291–300.