No abstract

The chemical compositions of cultivated 3 year-old bamboo culms of Gigantochloa brang, G. levis, G. scortechinii and G. wrayi were studied. The culms exhibited different chemical composition in extractives, α-cellulose, lignin and ash contents between the bamboo species, location in the culms and position at the nodes and internodes. The extractive content in four species ranged from 8.30 to 9.23%. The extractive content of G.brang, G.levis, G.scortechinii and G.wrayi were 8.30%, 9:23%, 8:00% and 8.62% respectively. The holocellulose content for G. levis were 85.08%, G. wrayi 84.53%, G. brang 79.94% and G. scortechinii 74.62%. The holocellulose content for the cultivated bamboo genus Gigantochloa were 74% to 85%. The α-cellulose is the chemical constituents in the holocellulose. The highest was G.brang (51.58%) followed by G. scortechinii (46.87%), G. wrayi (37.66%) and G. levis (33.80%). The lignin content ranged between 24.84 to 32.65%. The highest were obtained in G. scortechinii (32.55%), G. wrayi (30.04%), G. levis (26.50%) and lowest in G. brang (24.83%). The ash content in four species of Gigantochloa bamboo ranged between 0.88 to 2.86%. The ash content is the highest in G. scortechinii (2.83%) follow by G. levis (1.29%), G. brang (1.25%) and the lowest in G. wrayi (0.88%).

Two Malaysian hardwoods, acacia (Acacia mangium Wild.) and sesendok (Endospermum malaccense Bent. ex Müll. Arg.) that had been previously subjected to oleo-thermal modification, were studied to determine their dynamic sorption kinetic behaviour. All specimens were thermally modified in palm oil at 180°C, 200°C, and 220°C and 3 h treatment time. Data were analysed using the parallel exponential kinetics (PEK) model, and excellent fits to the experimental data were obtained. The relation between the monolayer water and polylayer water was also examined by the Hailwood-Horrobin (H-H) model at a range of relative humidity (RH) values. The PEK model divides the sorption kinetics curve into a fast and slow sorption processes. Characteristic times of the two processes at various RH showed sorption hysteresis with all of the specimens only in the slow process. However, with mass change data, sorption hysteresis occurred with both the slow and fast processes. By comparing H-H and PEK models, it was found that the fast and slow sorption process of untreated and treated E. malaccense could possibly be linked, respectively, to monolayer and polylayer formation from 5 to 40% RH. No such correlation was found for A. mangium, however.

This paper investigates the effect of heat treatment on Semantan bamboo (Gigantochloa scortechinii) with emphasis given to their properties and durability. Matured four-year-old bamboo culms were harvested and subjected to high temperature condition using palm oil as a heating media. Two groups of samples, green and air-dried, were used. The temperatures applied were 140 • C, 180 • C and 220 • C, with exposure duration of 30, 60 and 90 min, respectively. The results of the investigations show that the heat-treated bamboos retained most of their original physical and strength properties after undergoing the heat treatment. Green or air-dried bamboo culms can be dried to an MC of 6-7% within 2-3 h of treatment. The basic densities of bamboo were found to improve slightly by the heat application. The overall strengths properties of the heat-treated bamboo were found to decrease. The modulus of elasticity in the bending strengths was reduced between 2 and 33% in the green-and 6-9% in the air-dried conditions. For the modulus of rupture in the bending strengths, the value was reduced between 1 and 23% in green-and 4-16% in air-dried conditions. The compression strengths were reduced in the range between 2 and 3% in green-and 2-35% in air-dried conditions. The shear strengths were reduced in the range between 16 and 24% and 12-24% in in green-and air-dried conditions, respectively.

No abstract

No abstract

This paper discusses the results from the initiative that has been undertaken to utilize residues from oil palm re‐plantation, particularly the oil palm trunk (OPT) for the production of laminated veneer lumber (LVL). Efficient use of such residues is vital in order to minimize the environmental burdens associated with the disposal of the oil palm residues, thus ensuring the future growth of Malaysian palm oil industry. The bending and compression strength of the OPT LVL produced were accessed and compared with Malaysian oak (formerly known as rubberwood), timber species that is commonly used in the manufacture of furniture in Malaysia. Properties of OPT LVL were found almost comparable to solid Malaysian oak in terms of bending and compression strength. Combination of OPT veneers with several layers of Malaysian oak veneers during the process of LVL manufacturing has resulted in the improvement in bending and compression strength of the LVL as compared to those produced entirely from OPT. In addition, such practice also produced LVL board with far less variation in strength properties as compared to solid OPT properties. With further research and development embarked upon the gluability of the OPT materials, the overall performance of the OPT LVL could be improved for commercial utilization of OPT wastes in the near future. Development higher value‐added by‐products from oil palm industry residues, would benefit the industry through reduction of the overall environmental burden and would place it on a new environmentally sustainable platform.

No abstract