Hashim W. Samsi

Analysis of the water vapour sorption isotherms of thermally modified acacia and sesendok

Abstract Two Malaysian hardwoods, acacia (Acacia mangium) and sesendok (Endospermum malaccense), that had been subjected to oleo-thermal modification were studied to determine their sorption isotherm behaviour using a dynamic vapour sorption apparatus. All the specimens were thermally modified using palm oil at three different temperatures (180, 200 and 220°C) and three different times (1, 2 and 3 h). The results showed that there was a reduction in equilibrium moisture content at each target relative humidity due to the heat treatment, but that the two wood species showed different behaviour in this respect. The adsorption isotherms were analysed using the Hailwood and Horrobin model, with excellent fits to the experimental data. The monolayer water and polylayer water were both reduced at a range of relative humidity values of the treated samples, although behaviour between the two wood species differed. Heat treatment resulted in an increase in hysteresis ratio, which was probably due to the increase in matrix stiffness of the cell walls.

Analysis of water vapour sorption of oleo-thermal modified wood of Acacia mangium and Endospermum malaccense by a parallel exponential kinetics model and according to the Hailwood-Horrobin model.

Abstract 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.

Effect of heat treatment using palm oil on properties and durability of Semantan bamboo

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.

Minimizing the environmental burden of oil palm trunk residues through the development of laminated veneer lumber products.

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.

Basic density and strength properties of cultivated Calamus manan

This research investigates the basic density of Calamus manan cane grown in plantation and its relationship to strength. Cane samples were obtained from two plantation area in Malaysia. The results indicate that the lower part of the cane shows to have higher basic density compared to the higher part of the cane. The older canes (18 and 24 year-old) show a higher basic density compared to young canes (7 and 11 year-old). Samples with higher basic density show to have higher strength compared to those with lower basic density. Older canes indicate to have a 7-8-times higher strength compared to young canes.

Thermal Degradation Analysis on 4-year-old Culms of Cultivated Tropical Bamboo Bambusa Vulgaris

The thermal degradation of matured 4-year-old culms of cultivated tropical bamboo Bambusa vulgaris was studied and analyzed . The analysis using the F ourier Transform Infrared Spectroscopy and Thermal Gravimetric Analysis revealed the presence of basic functional groups in the bamboo which consists mainly of ester, carbonyl, and hydroxyl groups. The chemicals present in the bamboo vary depending on the location of the samples taken from the bamboo culms. The moisture content and extractive were omitted in the kinetic study since they constituted less than 10% of the overall chemicals in bamboo and observed below 100℃. Low reactivity of lignin components and hemicellulose in bamboo occurred due to the peculiarities of the chemical structure and composition. The mechanism of the decomposition reactions taken as a three-step reaction which involved the activation energies and dynamics related to volatile fractions of hemicellulose, cellulose, and lignin. Activation energies of 46, 100, 105, 127, and 236 kJ/mol applied for all of the bamboos . The activation energy carried could provide better insight into the thermal decomposition process. It provides more information on critical energy needed to start a reaction. The decomposition activation energy range obtained could assist in understanding the thermal decomposition stability of the bamboo fibers and application in natural fiber reinforced polymer composite industry.

Mechanical and Physical Properties of Particle Board Made from Silaned and NaOH Modified Kelampayan (Neolamarckia cadamba) Particles

The objective of this study is to determine the mechanical and physical properties of Particleboard made from modified particle of Kelampayan (Neolamarckia cadamba). The particles were modified with Silane and Sodium Hydroxide (NaOH) by soaked the particle for 24 hours with different ratio ( Kelampayan + Silane, Kelampayan + NaOH, and Kelampayan + Silane + NaOH). The result showed that the mechanical and dimensional stability of the treated wood were improved. Particleboard made from 0.8 mesh particles treated with Silane and NaOH were highest value of bending strength modulus of rapture (MOR) 22.89MPa, modulus of elasticity (MOE) 3916.88MPa and Internal Bond properties 0.48214 MPa whereby particleboard made from 0.5 mesh particles treated by Silane were highest value for bending strength (MOR) 15.75MPa, MOE 2905.34 and Internal Bond properties 0.5748MPa.Outcome of this proposed research will provided valuable databases to the wood based industry to use Kelampayan as an alternative raw material in their down streams production such as particleboard, medium-density board and chipboard manufacturing.