The Glue Joint Strength of Laminated Timber Decking made from Three Malaysian Hardwood Species

Glue joint strengths of laminated timber decking made from three Malaysian hardwood species i.e. Kempas (Koompassia malaccensis), Nemesu (Shorea pauciflora) and Seraya (Shorea curtisii) were evaluated. Single and mixed species laminations were produced using a phenolresorcinol formaldehyde adhesive at room temperature. Shear block tests were performed according to the ANSI/ASTM D 905-49(76) specification. All specimens except one exhibited high glueline shear strength values with each combination, exceeding the minimum industrial requirements of 5515 kilopascal (kPa) and 4137 kilopascal (kPa) for dry and wet specimens, respectively. A comparison between laboratory and factory-made assemblies and various factors affecting the glueline shear strength of these assemblies are discussed

The Durability of Phenol-Resorcinol Formaldehyde Glue Joints on Three Malaysian Hardwood Species

The integrity and durabilily of phenol-resorcinol fOrmaldehyde glue joints on three Malaysian hardwood species were evaluated. Single and mixed-species laminations were produced using phenol-resorcinol formaldehyde adhesive at room temperature. The integrity of the glue bond to delamination was lested according to the ASTM D 1101-59 specification. All combinations, produced very low delemination percentage levels and met the requirement specified by AlTC. The highest delamination percentage was shown by Kempas-Kempas combination with only 4.7% and the lowest was Seraya - seraya combination with 0.0% delamination. Mixed-species combinations offered lower percentage of delamination that their single-species counterparts

Vessel-Length distribution in stems of rattan (Calamus SPP.)

Vessel-length distributions in the stems of rotan manau (Calamus manan Miq.), rotan dok (c. omatus Blume) and rotan jelayang (c. peregrinus Furtado) have been calculated from measurements ofparticle penetration. Due to the limitation of the length of the samples, the longest class of vessel determined was below 40 cm. Approximately, 71-80% of the vessels that were counted for the rattan stems were more than 36 cm long. The largest percentage of vessel in this class was Calamus manan followed by C. peregrinus and C. omatus. The shortest vessel-length distributed was in the class of 6-9 cm long which constituted 27% of the vessels counted in the stem of C. peregrinus. The shortest vessel-length distributed respectively in C. manan and C. omatus were in the class of 9-12 cm long (6%) and 12-15 cm long (8%). The shorter vessels found distributed in the rattan stems could either be the vessels that end orform bridges at the leaf trace complex near the leaf base (nodal section) or could be the smaller metaxylem vessels that are distributed near the periphery of the rattan stem. The appropriate way of estimating the distribution of vessel-length of any stem is to use sample in the experiment longer than the longest available vessel

Sustainable supply of wood and fibre: does Malaysia have enough

Malaysia is the world’s largest exporter of tropical timber (all products), at FOB value of RM 21.5 billion in 2005, followed by Indonesia and Brazil. In 2004, Malaysia overtook Indonesia as the leading exporter of plywood with just over 4.35 million cubic metres (m3 ), but in 2005 China outstripped all producer countries including Malaysia (5.13 million m3) as the largest exporter of tropical plywood. Although the timber industry accounts for less than 3% of total manufactured exports, it has strong industrial linkages integrating about 750 small and medium enterprises (SMEs) with another 1,500 smaller production units. Moreover, this sector is one of the few successful industry clusters developed under the Second Industrial Master Plan. To ensure continuity of sustainable supply of wood and fibres to industries, the government needs to strengthen and harmonize some policies related to: Sustainable Forest Management through: • Better management of forest resources in accordance with the prescriptions given in Forest Management Plans and compliance with SFM (Sustainable Forest Management) requirements et al, in ensuring continuity of log outflow at sustainable levels; • Review cases of harvesting in excess of prescribed allowable cuts, as in Sabah, to ensure reversion to sustainable-level log production; and • Management of log production in the interest of meeting domestic needs especially in log-deficit Sabah, with a view to banning log exports. Forest Plantations, through: • Encouraging private-sector initiatives in forest plantations with financial incentives; • Coordinating and monitoring, nationwide, the progress of forest plantation activities that benefit from Malaysia Plantation Industries Corporation’s (MPIC) assistance programme for forest plantations; and • Permiting agro-forestry practices in forest plantation projects. Biomass Development through: • Intensification of use of non-conventional raw materials (kenaf, oil palm, bamboo, rattan and other non-wood resources), where technically and economically feasible. • Review of the existing R&D policies to encourage more private sector participation in R&D for processing technology and use of non-conventional raw materials. Resource Recycling and Wood Wastes through: • Full utilisation of wood residues from logging and wood-processing industries such as saw-milling and plywood and particle board manufacturing; and • Intensification of use of wood residues generated by management of perennial crop plantations by activities such as pruning and replanting of trees (rubber, coconut, palm oil and crop residues generated by agricultural production); Importation of Raw Materials: • Increase importation of raw materials and components at competitive prices and allow the timber industry to focus on the possibility of producing tertiary products. If all the strategies mentioned above are followed, we believe that the industry has the fundamentals to remain competitive. However, it has to compete with greater intensity to remain ahead in the increasingly competitive world market. The timber sector has a lot to contribute to the national economy, in return for the supportive services that it has received from the government

Responses to Wood and Wood Extractives of Neobalanocarpus heimii and Shorea ovalis by the drywood termite, Cryptotermes cynocephalus (Isoptera : Kalotermitidae)

Drywood termites, Cryptotermes cynocephalus Light, were exposed to wood blocks and wood extractives of Neobalanocarpus heimii King and Shorea ovalis' Korth.} Bl. The results showed that the termites' survival and wood consumption were significantly higher on S. ovaHs than on N. heimii. Termite survival and feeding response obtained on bioassays with sawdust, extracted sawdusts and extract treated filter paper, indicated that one factor affecting the variation in relative susceptibility of the woods to termite attack could be secondary compounds present in the wood

Attractant and phagostimulant effects of aqueous extract of cassava, Manihot esculenta, tuber on Coptotermes curvignathus and Coptotermes gestroi (Isoptera: Rhinotermitidae)

Effects of aqueous extracts of cassava tuber, Manihot esculenta, were evaluated on subterranean termites, Coptotermes curvignathus and Coptotermes gestroi (Isoptera: Rhinotermitidae). The termites were exposed to filter papers that had been treated with various concentrations of aqueous extract of cassava, and their responses to the treated papers in terms of their consumption, survival and attractiveness were compared with those of untreated papers. The results show that C. curvignathus and C. gestroi significantly preferred papers that had been treated with 10% and 5% of cassava tuber extract, respectively. Both termite species were significantly attracted to and consumed more treated papers than the untreated papers. Survival rates in treated groups were slightly lower than those in the control, but they were not significantly different. However, the termites survived poorly on papers that had been treated with cassava tuber extract higher than 15% concentration. This could be due to intoxication caused by cynogenic glycosides present in the cassava

Fibre saturation point of lesser-known timbers from Sabah

The fibre saturation point (FSP) values of some 'OT' timbers from Sabah, Malaysia were evaluated. 'OT' is a term used to refer to a number of unidentified or unknown timbers and also S01ne identified lesser known timbers of Sabah. The fibre satumtion point values of these 30 species ofOT timbers mngefrom 17 - 33%. Determination of fibre salumtion point in relation to OT wood properties is very useful in timber drying, conversion and timber utilization

The dynamics of radial growth of three selected tropical tree species studied through knife-cutting method

Tropical trees which lack distinct growth rings have caused difficulty in estimating the growth rate of those trees. This has resulted in limited knowledge concerning tropical tree growth pattern and rate of increment. This study aimed to assess the radial growth and cell production rate of three selected tropical species, namely, Macaranga gigantea, Endospermum diadenum and Dipterocarpus costulatus, with different diameters at breast height. For this purpose, knife-cutting method was adopted in this study. A knife was inserted through the bark into the outer xylem of a tree to wound the cambium and remove immediately. Wood discs containing wound area were collected from living trees after a period of time. Transverse sections of 20-25 µm in thickness were obtained through sliding microtome and dehydrated in a graded series of ethyl alcohol before staining with safranin and fast green. Dibutyl phthalate xylene (DPX) was used as a mounting medium for preparation of permanent microscope slides. The species-related anatomical response to wounding was identified and used to define the time of marking. Results show that radial growth rate and cell production rate varied across species and tree sizes. M. Gigantean and E. Diadenum showed faster growth rates than D. Costulatus, especially in small diameter classes. Meanwhile, D. Costulatus had the lowest growth rate and cell production rate. Thus, both the pioneer species are thus considered to grow faster in smaller stem size than larger stem size, while the study succeeding species grow faster in larger stem size than smaller stem size

Characteristics of pulp produced from refiner mechanical pulping of tropical bamboo (Gigantochloa scortechinii)

Bamboo properties are somewhat similar to certain timbers but it has an advantage of having longer fibres, making it suitable for the production of pulp for paper and hardboard. However, the pulping process is a very crucial stage to produce fibres with an optimum quality. This study was carried out to characterize the pulp of Giganrochloa scortechinii using refiner mechanical pulping (RMP). The parameters evaluated included the effects of pre-treatment soaking in NaOH or steaming of chips and effects of refiner plate gap on pulp quality. Pulp quality was assessed based on the properties, yield, and lignin content of fibres. The pre-treatment with NaOH at 60°C for 6 h was found to produce superior quality pulp and lesser lignin content compared to pre-treatment by steaming at 150°C for 3 h. Meanwhile, the refiner plate gap test showed that the two cycles of refining (2.5-mm followed by 0.5-mm plate gap) reduced the lumpiness of the fibre, but it had lower felting power and Runkel ratio. Two cycles of refining process also led to higher fibre yield, produced more unbroken and slender fibres as compared to when one cycle treatment using 2.5-mm plate gap was used