No abstract

A study in enhancing the strength properties of Rhizophora apiculata by turning the solid wood into an engineered laminated board was executed. The matured Rhizophora species was selected from peat swamp forest in Sibu, Sarawak. The trunk was segregated into three parts, namely the bottom, middle and top portion and subsequently sawn into wooden planks. The laminated boards were cut into specific thicknesses and immediately bonded with an adhesive by pressed drying. Preparation for solid and laminated boards testing samples followed the ISO and ASTM standards. Properties such as the moisture content, density, basic density, static bending (MOR and MOE) and compression were determined. The results show an improvement in properties from the solid to laminated board. The values in density, MOR, and MOE increased in the range of 2-6%, 29-42%, and 13-36%, respectively. However, the values of the moisture content, basic density, and compression, indicated a vice versa trend ranging from 1-2%, 2-6%, and 8-24%, respectively. The bottom portion was more durable and robust compared to the other portions.

This study summarizes the research on organic fillers, where eggshells were used as the reinforcement and banana peels as the matrix in the manufacturing of biocomposite thin film. Banana peel fibers exhibit a good characteristic of renewable material for the substitution of cement-based composites. However, biocomposite properties are limited by the poor adhesion between natural fiber interface and polymer matrix, which can be improved by chemical modification of fibers. In this research, banana peels were subjected to silane treatment. Biocomposite thin film manufacturing processes were carried out using blending and hand lay-up techniques with various concentrations of epoxy/waste banana peels/eggshell filler (EWE) ratios (EWE 0%, EWE 5%, and EWE 10%). X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and thickness swelling test were conducted on silane-treated and untreated banana peel biocomposite samples. In XRD analysis, it was found that EWE 10% sample had the highest crystallinity compared to EWE 0% and EWE 5%, and silane-treated samples had higher crystallinity than untreated samples.  For FTIR test, lignin component was removed in silane treatment based on the changes of IR peak characteristic where the new bonds (-Si-O-C-, -Si-O-Si-, and -Si-C-) were found in treated samples. Besides, TGA results showed that the thermal stability of silane-treated samples was improved significantly with the increase of eggshell filler percentage, which was proven by the decrease in the decomposition stage. In thickness swelling test, the samples achieved higher swelling percentage as the percentage of eggshell filler increased. However, the decrease of 5–6% in thickness swelling of treated samples was possibly offset by the enhancement in fiber/matrix interfacial adhesion.

This study was carried to investigate changes in the oil heat treated 18-years old of planted Acacia mangium. Harvested trees segregated into bottom, middle and top portions containing heartwood and sapwood were oil heat treated in stainless tank with palm crude oil as heating medium at temperatures of 180 o C, 200 o C and 220 o C for 30, 60 and 90 minutes respectively. The evaluation of the changes in the wood were performed by standards using a Minolta Chroma Meter, TAPPI Standard T204 om-88, TAPPI Standard T203 cm-99, TAPPI Standard T222 cm-02, and BS EN 310:1993 static bending tests. The relationship between the changes in the colour, mechanical and chemical composition, were made using correlation analysis. The result showed oil-heat treatment reduced the lightness of the wood and darkened the both parts of the wood. The strength of the wood reduced slightly after the oil-heat treatment. In the chemical compositions, the percentages of the holocellulose, α-cellulose, hemicellulose and extractive contents decrease with the increase in treatment duration and temperature. The oil heat treatment process at 200°C for duration 60 minutes is recommended for acacia mangium wood as it improved the colour of Acacia mangium and standardized the colour of sapwood and heartwood. The loss in strength at this temperature and duration is acceptable as the treated wood only loss up to 15% strength in MOR and 10.7% in MOE.

Oil palm fronds are one of the biomass residues originating from oil palm plantations. It has great potential to be used as an alternative material for the composite boards industry to reduce dependency on wood-based raw materials. The fronds are obtainable all the year round and in big quantity. The oil palm fronds had been processed as compressed oil palm fronds to form such a potential composite board in this topic. A composite board from compressed oil palm fronds was produced by removing the fronds’ leaflets and epidermis. The sample was sliced longitudinally into thin layers and compressed into an identical thickness at about 2 to 3 mm. Pieces of the sample were dry using the air-dried method. They were then mixed with phenol and urea-formaldehyde of resins in the range of 12-15% and compressed again with another layer forming a composite board. Standard outlined by the International Organization for Standardization (ISO) tested for their physical and strength properties of composite board. Found that the physical and strength aspects’ properties show that the composite board possessed characteristics at par or equivalent. The composite board from compressed oil palm fronds has good prospects to be used as an alternative to wood. Thus, this characteristics can overcome the shortage in materials supply in the wood-based industry.