Gluability of some Woody Species Grown in Sudan.

No Thumbnail Available
Nagla Abd El Hafize Ahmed Daw, El Beit
Journal Title
Journal ISSN
Volume Title
Scarcity and bad commercial quality of Sudanese logs made some specialty for the Sudanese as well as for tropical timber. reconstituted wood would be the solution of such types of problems. Little is known about timber characteristics in Sudan and there is no enough information in the field of bonding and adhesives. Thus, such situation and needs were the reason of this study which was carried out to investigate the gluability of the timber of some tree species grown in Sudan. The study used Acacia ampliceps. Acacia nilotica. Acacia senegal, Ailanthus excelsa, Anogeissus leioccarpus, Azanza jurckeana, Balanires aegyptiaca. Boswellia papyrifera,Calatropis procera, Callirris sp Combretum glutinosum, Dalbergia melanoxylon Eucalyptus microtheaca, Faidherbia albida, Khaya senegalensis. Sc!erocarya birrea. Sterculia Setigera. Syzygium guineense and Ziziphus .spina-christi. Air dried specimens; three sample trees for each species were glued using four commercial adhesives: polyvinyl, hot melt postic adhesives; and animal glue. Wood density, shear strength parallel to the grain and shear bond strength were investigated. In order to understand the effects of wood moisture content, pressure applied and pressing time, specimens of A. nilotica, Ailanthus excelsa, Anogeissus leiocarpus. Falbida, K. senegalensis and Z. spina-christi were prepared and bonded with polyvinyl adhesive at equilibrium moisture content and at 20% moisture content pressed under 150, 100 and 50 bar for 45, 30 and 15 minutes. Then shear strength for glued joints was recorded. Significant differences (p=0.05) in gluability were found between species and adhesives, but Animal glue showed insufficient gluing. For the effect of moisture content, pressure and pressing time it was found that A. nilotica showed interaction between moisture content and pressing time also between pressure and pressing time while the rest five studied species revealed interaction between the three studied factors (moisture content, pressure and pressing time). It is concluded that Animal glue used can be suitable for paper and paperboard assembly, hot melt and postic adhesive exhibited poor bond strength. Whereas polyvinyl adhesive provided acceptable bond strength. Polyvinyl adhesive showed less bond strength with an increase of wood moisture content. In general polyvinyl adhesive took less time to develop strength than that prescribed by the manufacturer. All species studied were suitable for gluing with Polyvinyl Adhesive with bond strength approaching wood strength. For the 19 studied species it is recommended that polyvinyl adhesive could be successfully used in wood working and furniture industry in Sudan. Animal glue for paper and paper board gluing and hot melt and postic adhesives for low strength products (e.g. block boards). Air-drying or wood seasoning before gluing is highly recommended.
Gluability of some Woody Species Grown in Sudan