Moisture Properties of Heat-Treated Scots Pine and Norway Spruce Sapwood Impregnated with Wood Preservatives
Keywords:
Heat-treated wood, pine tar, secondary treatment, water repellency, water uptakeAbstract
An experiment was conducted on commercially heat-treated (HT) Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst.) sapwood collected from Ht Wood AB, Arvidsjaur, Sweden. Secondary treatment on HT wood was performed in laboratory scale by impregnating with water-repellent preservatives (a commercial one and pine tar) to evaluate their retention and different moisture-related properties. Preservative solutions were impregnated using a simple and effective method. Wood samples were heated at 170°C in a dry oven and were immediately immersed in preservative solutions. Considerable retention was observed in HT wood, particularly in pine. Moisture adsorption properties were measured after conditioning in a high-humidity environmental chamber (4°C and 84% RH). Experimental results showed that secondary treatment enhanced moisture excluding efficiencies by decreasing equilibrium moisture content, suggesting better hydrophobicity. Soaking test in water showed that antiswelling and water repellence efficiencies improved, especially in tar-treated wood. In addition, this type of treatment significantly decreased water absorption. It was also possible to decrease volumetric swellings. Thus, secondary treatment of HT wood with preservative, in particular with tar, improved dimensional stability and water repellency.References
Ahmed SA, Sehlstedt-Persson M, Karlsson O, Morén T (2011) Uneven distribution of preservative in kiln-dried sapwood lumber of Scots pine: Impact of wood structure and resin allocation. Holzforschung, doi:10.1515/HF.2011.126.nBailey PJ, Preston RD (1970) Some aspects of softwood permeability. II. Flow of polar and non-polar liquids through sapwood and heartwood of Douglas fir. Holzforschung 24(2):3-45.nBooker RE (1990) Changes in transverse wood permeability during the drying of Dacrydium cupressinum and Pinus radiata. NZ J For Sci 20(2):231-244.nBoonstra MJ, Rijsdijk JF, Snader C, Kegel E, Tjeerdsma B, Militz H, van Acker J, Stevens M (2006) Microstructural and physical aspects of heat treated wood. Part 1. Softwoods. Maderas Cienc Technol 8(3):193-208.nDe Groot RC (1994) Comparison of laboratory and field methods to evaluate durability of preservative-treated shakes. Wood Fiber Sci 26(3):306-314.nDoi S, Kurimoto Y, Ohmura W, Ohara S, Aoyama M, Yoshimura T (1999) Effects of heat treatment of wood on the feeding behavior of two subterranean termites. Holzforschung 53(3):225-229.nDonath S, Militz H, Mai C (2004) Wood modification with alkoxysilanes. Wood Sci Technol 38(7):555-566.nDrysdale J (2002) Global regulatory changes restrict the use of CCA. NZ J Forestry 47(3):9-10.nEpmeier H, Kliger R (2005) Experimental study of material properties of modified Scots pine. Holz Roh Werkst 63(6):430-436.nEsteves BM, Pereira HM (2009) Wood modification by heat treatment: A review. Bioresources 4(1):370-404.nHakkou M, Pétrissans M, Gérardin P, Zoulalian A (2006) Investigations of the reasons for fungal durability of heat-treated beech wood. Polym Degrad Stabil 91 (2):393-397.nIslam MN, Ando K, Yamauchi H, Hattori N (2009) Effects of species and moisture content on penetration of liquid in laser incised lumber by the passive impregnation method. Eur J Wood Prod 67(2):129-133.nJämsä S, Viitaniemi P (2001) Heat treatment of wood—Better durability without chemicals. Pages 21-26 in AO Rapp, ed. Review on heat treatments of wood, 9 February 2001, Antibes, France. BFH, Hamburg, Germany.nJohansson D, Morén T (2006) The potential of colour measurement for strength prediction of thermally treated wood. Holz Roh Werkst 64(2):104-110.nKarlsson O, Sidorova E, Morén T (2011) Influence of heat transferring media on durability of thermally modified wood. Bioresources 6(1):356-372.nKollmann FFP, Côté WA (1984) Principles of wood science and technology. Volume I: Solid wood. Springer-Verlag, Berlin and Heidelberg, Germany, and New York. 592 pp.nMai C, Militz H (2004) Modification of wood with silicon compounds. Inorganic silicon compounds and sol-gel systems: A review. Wood Sci Technol 37(5):339-348.nMazela B (2007) Fungicidal value of wood tar from pyrolysis of treated wood. Waste Manag 27(4):461-465.nMetsä-Kortelainen S, Antikainen T, Viitaniemi P (2006) The water absorption of sapwood and heartwood of Scots pine and Norway spruce heat-treated at 170°C, 190°C, 210°C and 230°C. Holz Roh Werkst 64(3):192-197.nNordic Wood Preservation Council (2005) Wood preservatives approved by the Nordic Wood Preservation Council. No. 73. Oslo, Norway. http://www.bfafh.de/inst4/45/pdf/nwpcappr.pdf'>http://www.bfafh.de/inst4/45/pdf/nwpcappr.pdfnOlsson T, Megnis M, Varna J, Lindberg H (2001) Study of the transverse liquid flow paths in pine and spruce using scanning electron microscopy. J Wood Sci 47 (4):282-288.nRak J (1976) Leaching of toxic elements from spruce treated with ammoniacal solutions of copper-zinc-arsenic preservatives. Wood Sci Technol 10(1):47-56.nRapp AO, Sailer M (2001) Oil heat treatment of wood in Germany—State of the art. Pages 45-62 in AO Rapp, ed. Review on heat treatments of wood, 9 February 2001, Antibes, France. BFH, Hamburg, Germany.nRowell RM (1983) Chemical modification of wood. Forest Prod J 6(12):363-382. Abstract.nSchultz TP, Nicholas DD (2002) Development of environmentally-benign wood preservatives based on the combination of organic biocides with antioxidants and metal chelators. Phytochemistry 61(5):555-560.nThompson WS, Dust JV (1971) Pollution control in the wood preserving industry. Part I. Nature and scope of the problem. Forest Prod J 21(9):70-75.nWalters CS, Côté WA (1960) The distribution of pentachlorophenol in the micro-structure of basswood. Holzforschung 14(6):183-189.nWang JY, Cooper PA (2005) Effect of oil type, temperature and time on moisture properties of hot oil-treated wood. Holz Roh Werkst 63(6):417-422.nWei C, Tyree MT, Bennink JP (2000) The transmission of gas pressure to xylem fluid pressure when plants are inside a pressure bomb. J Exp Bot 51(343):309-316.nWelzbacher CR, Rapp AO (2004) Determination of the water sorption properties and preliminary results from field test above ground of thermally modified material from industrial scale processes. IRG/WP 04-40279. International Research Group on Wood Protection, Stockholm, Sweden.nWestin M, Rapp A, Nilsson T (2006) Field test of resistance of modified wood to marine borers. Wood Mater Sci Eng 1(1):34-38.nZaman A, Alén R, Kotilainen R (2000) Thermal behavior of Scots pine (Pinus sylvestris) and silver birch (Betula pendula) at 200-230°C. Wood Fiber Sci 32 (2):138-143.n
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