Nor Yuziah Mohd Yunus

Manufacture and properties of oil palm particleboard

Malaysia has a total of more than 4 million hectares of oil palm plantation. Besides the palm oil, the industry generates massive quantities of oil palm trunks (OPT), oil palm fronds (OPF) and empty fruit bunch (EFB) available from replanting and through routine field and mill operation. With a 25 years rotation of planting regime, 70,000 hectares is due for replanting every year and it is estimated that about 21.63 million cubic meters (14 million tones) of oil palm trunk will be available. If this raw material is not utilized properly they will be a source of environmental concern. This paper discussed the manufacture and properties of particleboard made from oil palm trunk particles. The oil palm trunk (25 yrs old) was supplied by MPOB, Bangi, Selangor. The trunk was converted into strands using a disk flaker and into particles by passing through a dust extractor. Single layered UF board and three-layered board were made and their properties determined. Boards make from unscreened particles with 700kg/m3 density, 12% resin content and without wax have the highest MOR (26.76 MPa) and MOE (2843 MPa) values. Lowest MOR & MOE values was exhibited by boards produced from PS of >1.0 mm with 500kg/m3 density, 8% resin content and 1% wax. Highest IB (1.54 MPa) was shown by boards made from >1.0 mm PS with 700 kg/m3 density, 12% resin and without wax. No boards were able to meet all the requirements of the BS Standards. Particleboard can be made from oil palm trunk particles, however further studies have to be conducted to improve their properties.

Influence of Resin Molecular Weight on Curing and Thermal Degradation of Plywood Made From Phenolic Prepreg Palm Veneers

The present work evaluates curing and the thermal behavior of different molecular weight phenol formaldehyde (PF) resins used to prepare PF prepreg oil palm stem veneers. The physical properties (solid contents, gelation time, pH, and viscosity) of PF resins were determined. The molecular weight of resins was characterized by gel permeation chromatography, whilst thermal properties were determined by differential scanning calorimetry and thermogravimetric analyses. The average molecular weight of PF resins were 526 g/mole (low), 1889 g/mole (medium), and 5178 g/mole (control - commercial). Among the resins, medium (MMwPF) gives better thermal stability with a retained weight of 48.9% at 300°C. High (Commercial PF) had a low decomposition temperature (109.3°C) which occurred within 11 min. Both low (LMwPF) and MMwPF started to melt at ≥120°C. Based on strength and shear values, phenolic prepreg palm veneers can be prepared using either low or medium molecular weight PF but with varying results. In all cases, the mechanical properties of palm plywood made from PF prepreg veneers were superior to those made from PF-bonded plywood using the commercial process.

Effects of Resin Content Dosage, Density and Wax Addition on the Physical and Mechanical Properties of Particleboard from Oil Palm Trunk

This study investigates the effects of resin dosage, board density and wax addition on physical and mechanical properties of oil palm trunk particleboard. The oil palm trunk was harvested from FELDA Ulu Jempul, Pahang and flaked to produce the particles. The particles were blended with urea formaldehyde (UF) as a binder and added with wax in order to enhance board dimensional stability. The oil palm trunk particleboards are consolidated at temperature of 165 °C with pressure cycle of 1800, 1200 and 500 psi for six minutes. Mechanical properties, namely, modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), physical properties of water absorption (WA) and thickness swelling (TS), are tested according to Japanese Industrial Standards (Particleboard, Japanese Standards Association, Japan, 2003). The results for different resin contents show that the particleboards with 12% resin content have given better performance in physical and mechanical properties as compared to 10% and 8%. Besides, the results for different densities show that the mechanical properties of particleboards improve as the density increases which was the particleboard with density 600 kg/m3 with MOR and MOE of 6.81 and 957.17 MPa, respectively, which gives the best performance. Addition of 1% wax was improve the physical properties of the board from 15.6 to 36.9%. However, wax addition gives negative impact on the mechanical properties of particleboard.

Effects of Ratio on Particleboard from Cultivated Leucaena leucocephala (Petai Belalang) and Hevea brasiliensis (Rubberwood)

Suitability of new raw material for particleboard can be measured by testing the mechanical and physical properties’ performance. The objective of this study was to determine the strength of the particleboard manufactured by using different ratios of Leucaena leucocephala (petai belalang) and Hevea brasiliensis (rubberwood). Increasing ratio of L. leucocephala particles gave a positively significant increase in modulus of elasticity (MOE) and internal bonding (IB). Highest MOE was 3086 MPa with an 80:20, L. leucocephala: H. brasiliensis ratio. For physical properties, higher ratio of L. leucocephala leads to lower performance in physical strength. Resin content gave higher results for MOE and MOR and no significant change in IB with increase in percentage used. A strong negative correlation (r = −0.84**) was seen for resin content percentage. Overall, only board made with ratio 20:80 and board with 8% resin content did not meet the minimum required standard in BS EN. The study on the effects of ratio on the properties of particleboard indicated that the strength of the mechanical properties can be improved by increasing L. leucocephala ratio.

Effects of Particle Sizes and Board Densities on OPF Phenol Formaldehyde Particleboard Properties

In Malaysia, the search for methods of utilization of oil palm biomass (OPB) is an intensified Government agenda as the biomass availability is registered at approximately 14 million tonnes dry weight annually. In support of development of potential usage, oil palm frond (OPF) particleboard using phenol–formaldehyde resin was investigated using a 3 × 3 factorial experimental design. The parameters used were densities (500, 600 and 700 kg/m3) and particle sizes (0.5, 1.0 and 2.0 mm). The results of physical and mechanical properties, which have been tested according to Malaysian Standard, MS1787:2005, yielded the following conclusions. The bending strength showed improvement with an increase in density for all particle sizes. Both modulus of rupture (MOR) and modulus of elasticity (MOE) values decrease moving from small towards bigger particle sizes. Board made using particle size 0.5 mm with density 700 kg/m3 gave the best MOR (25.19 MPa) and MOE (3488 MPa) values. The internal bonding was also dominated by the same board at 0.70 MPa. Physical testing for thickness swelling (TS) emphasizes the difficulties currently known by OPT users. On average, the TS improved as the densities increase and as particle size decreases.

Impact of Alkaline Treatment on Mechanical Properties and Thickness Swelling of Exterior Particleboard Made from Kelempayan (Neolamarckia cadamba) Wood

Alkaline treatment was carried out to remove barrier for the interaction between wood particle and resin in order to develop exterior particleboard with better mechanical properties and dimensional stability. Kelempayan particles were treated using 0.5, 1, and 2% sodium hydroxide (NaOH) at 90 °C for 60 min. Phenol formaldehyde (PF) was used as binder for the boards. Single-layer particleboard with a density of 700 kg m−3 was fabricated from 0.5 and 1.0 mm particle sizes, bonded with 11% PF resin at 165 °C of hot press temperature. Experimental samples were tested for modulus of elasticity, modulus of rupture, internal bonding strength, and thickness swelling according to Malaysian Standards (MS 1787:2005). Based on the findings of this work, particleboards made from 0.5 mm particle size and treated with 2% NaOH had the highest mechanical performance and the lowest thickness swelling. The particleboards met the requirements of the MS standard for structural applications used in high humid conditions.

Physical and Chemical Properties of Different Portions of Oil Palm Trunk

A total of three-felled oil palm trunks (OPT) was obtained from the Ulu Jempul, Pahang. The physical properties of oil palm trunk were determined at different tree portions for basic density and distance from pith for moisture content. The finding revealed that the specific gravity and moisture content are significantly different on tree portion and highly significant difference for distance from pith. The chemical composition of the oil palm trunks was analysed for hot water, ash content, 1% NaOH, alcohol–toluene extracts, lignin, holocellulose and alpha-cellulose from bottom to top portion. Based on the results, there were significantly different between the tree portion and the highest value that was found at the top portion except for lignin content, holocellulose and alpha-cellulose. The highest percentage of the chemical properties were from hot water, ash content, 1% NaOH and alcohol–toluene extract at the top portion. Thus, the potential of using such oil palm trunk could serve as a raw material for the particleboard production.