Life table of Cochlochila bullita stål (hemiptera: tingidae) on Orthosiphon aristatus (blume) miq. and Ocimum basilicum l. in laboratory conditions

Ocimum tingid, Cochlochila bullita Stål (Hemiptera: Tingidae) is a pest of Lamiaceae plants such as basil, tulsi and coleus. It is now being recorded in Malaysia as a pest of the cat’s whiskers plant, Orthosiphon aristatus (Blume) Miq. Nevertheless, apart from its brief biological description, no other information is available. The life table of this pest was studied in laboratory conditions. Development time for C. bullita feeding on O. aristatus was 23.3 ± 0.9 days, which was found to be similar to those feeding on Ocimum basilicum (22.8 ± 0.3 days). Although C. bullita posts a higher mortality rate on O. aristatus than on O.basilicum (52% vs. 37%), the adult longevity of the bugs that feed on O. aristatus (♀: 33.9; ♂: 38.2 days) was found to be significantly higher than those bugs that feed on O.basilicum (♀: 27.2; ♂: 26.0 days). The pre-ovipostion, ovispostion and fecundity of C. bullita were also different between the host plants. The net reproductive rates (R0), finite rate of increase (λ) and intrinsic rate of increase (r) were also higher on O. aristatus (10.7504, 1.0690 and 0.0667), although there was an increased in immature survival on O. basilicum (6.0287, 1.0556 and 0.0541). Therefore, it is concluded that O. aristatus is as good as O. basilicum, or the population growth of C. bullita is more favoured as compared to O. basilicum

Production of low formaldehyde emission particleboard by using new formulated formaldehyde based resin

In order to preserve the global market competitiveness, the particleboard industry was affronted with challenges to reduce formaldehyde emission while maintaining the quality strength properties of particleboard. To counter the issue, particleboards with five different surface-to-core ratio were fabricated by applying newly formulated UF and MUF resins which were 30% surface: 70% core (3:7); 40% surface: 60% core (4:6); 50% surface: 50% core (5:5); 60% surface: 40% core (6:4) and 70% surface: 30% core (7:3) based on dry particle weight respectively. Formaldehyde emission and strength properties of the fabricated particleboard were investigated based on Japanese Industrial Standard, which are JIS A 1460 and JIS A 5908, respectively. All the MUF-bonded particleboard complied with the type 18 standard, whereas all the UF-bonded particleboard produced complied with type 13 except thickness swelling of the UF-bonded particleboard. The surface-to-core ratio applied in three layered particleboard for both resins exerted considerable influence on the strength properties and formaldehyde emission of particleboards produced from both resins. MUF-bonded particleboard with 40% surface and 60% core recorded the lowest formaldehyde emission (0.09 mg L-1) and highest strength properties. For UF-bonded particleboard, the ratio of 60% surface and 40% core showed the lowest formaldehyde emission (0.28 mg L-1) with better strength properties. This study highlighted the potential of MUF resin to replace UF resin due to its ability to produce F**** particleboard with better strength properties and lower formaldehyde emission according to JIS A 5908

Addition of propylamine as formaldehyde scavenger for urea formaldehyde-bonded particleboard

Rubberwood particleboard were produced using urea formaldehyde (UF) resin admixed with propylamine as formaldehyde scavenger. 1 % propylamine were incorporated into 8 %, 10 %, 12 %, 14 % and 16 % UF resins, respectively. The effectiveness of propylamine addition to reduce formaldehyde emission from particleboard was examined. Physical and mechanical properties were evaluated according to Japanese Industrial Standard (JIS). The results showed that addition of propylamine had reduced 33 to 65 % formaldehyde emission from particleboard made with different dosages of UF resin. However, the properties of the particleboard were adversely influenced by the addition of propylamine. Higher resin dosage (≥14 %) had counterbalanced the loss of strength and dimensional stability but accompanied by increased formaldehyde emission. As a conclusion, UF dosage of 14 % admixed with 1 % propylamine is the most ideal formulation to produce particleboard with low formaldehyde emission while maintaining the desired properties

Mechanical Properties of Laminated Veneer Lumber (LVL) Fabricated from Three Malaysian Hardwood Species

The application of laminated veneer lumber (LVL) has long been limited to non-structural elements in Malaysia. The LVL is commonly fabricated with veneer from low to medium density (290 to 630 kg/m3) softwood or temperate hardwood. The data on the properties of LVL made from medium to high density (567 to 687 kg/m3) tropical hardwood species is very limited. Therefore, this study investigated the mechanical and bonding properties of LVL fabricated from Malaysian hardwood species namely Kasai (Pometia spp.), Mengkulang (Heritiera spp.) and Kedondong (Canarium spp.). Different variables were studied: i) wood species; ii) loading surface (flatwise or edgewise), iii) grain direction (parallel and perpendicular), iv) treatment condition. The bending and compression test was carried out in accordance with EN 408:2012, while the block shear test was conducted based on EN14374:2004 and EN 314-1:2004. The results shows that the grain direction has the most significant effect (P ≤ 0.01) on the bending, compressive and bonding properties of the samples tested. The treatment conditions for block shear test also displayed significant effect on its shear strength. The samples loaded parallelly displayed bending values 320-450% higher than the samples loaded at perpendicularly. The compressive strength and compressive modulus are 323-365% and 523-2530% respectively when loaded parallelly. LVL performed better mechanically when loaded parallelly and when subjected to less extreme treatment conditions

Mechanical Properties of Laminated Veneer Lumber (LVL) Fabricated from Three Malaysian Hardwood Species

The application of laminated veneer lumber (LVL) has long been limited to non-structural elements in Malaysia. The LVL is commonly fabricated with veneer from low to medium density (290 to 630 kg/m3) softwood or temperate hardwood. The data on the properties of LVL made from medium to high density (567 to 687 kg/m3) tropical hardwood species is very limited. Therefore, this study investigated the mechanical and bonding properties of LVL fabricated from Malaysian hardwood species namely Kasai (Pometia spp.), Mengkulang (Heritiera spp.) and Kedondong (Canarium spp.). Different variables were studied: i) wood species; ii) loading surface (flatwise or edgewise), iii) grain direction (parallel and perpendicular), iv) treatment condition. The bending and compression test was carried out in accordance with EN 408:2012, while the block shear test was conducted based on EN14374:2004 and EN 314-1:2004. The results shows that the grain direction has the most significant effect (P ≤ 0.01) on the bending, compressive and bonding properties of the samples tested. The treatment conditions for block shear test also displayed significant effect on its shear strength. The samples loaded parallelly displayed bending values 320-450% higher than the samples loaded at perpendicularly. The compressive strength and compressive modulus are 323-365% and 523-2530% respectively when loaded parallelly. LVL performed better mechanically when loaded parallelly and when subjected to less extreme treatment conditions

Effect of post-thermal treatment on the density profile of rubberwood particleboard and its relation to mechanical properties

The objective of the study was to investigate the effect of heat treatment on the changes in density profile of rubberwood particleboard samples. The relationship between density profile and mechanical properties of particleboard samples was determined using regression analysis. Single layer particleboard made from rubberwood particles with dimensions of 340 mm × 340 mm × 12 mm and targeted density of 700 kg m-3 was heat-treated using oven and hot press at three different temperature levels, namely, 100, 150 and 200 °C for 30 min. All density profile attributes were significantly affected by heat treatment. Bending properties, internal bond strength and hardness were influenced by treatment temperature. However, samples treated using hot press had better mechanical properties compared with those treated using oven. Mean and peak densities exerted profound effects on mechanical properties of the samples

Properties of particleboard with oil palm trunk as core layer in comparison to three-layer rubberwood particleboard

Compaction ratio is highly dependent on the density of the wood materials used in the production of particleboard. Lower density wood materials will produce particleboard with higher compaction ratio and is believed to give better properties. The objective of this study was to evaluate the properties of threelayer particleboard made from rubberwood and oil palm trunk with different bulk density as the core layer, while the rubberwood fine particles served as surface layers for both types of particleboard. This study also investigated the effect of shelling ratios on the mechanical and physical properties of the threelayer particleboard. Melamine-fortified urea formaldehyde (UF) resin was used as the binder. The modulus of rupture (MOR), internal bond strength (IB) and thickness swelling (TS) of the particleboards were evaluated based on the Japanese Industrial Standard for particleboard (JIS A 5908:2003). The results showed that both species and shelling ratios are variables that influenced the mechanical and physical properties of the particleboard. Despite its lower compaction ratio, particleboard made from rubberwood alone had better strength properties and dimensional stability than particleboard made from a mixture of rubberwood and oil palm trunk

Behaviour of walls constructed using Kelempayan (Neolamarckia cadamba) wood wool reinforced cement board

This research investigated the behaviour of walls produced from wood wool cement board (WWCB) which were reinforced with a lesser known commercial timber, Kelempayan, when subjected to compression load. Kelempayan timbers were shredded into wood wool and used as reinforcement agent in this study. WWCB having dimensions of 600 × 2400 × 50 mm and 600 × 2400 × 75 mm, respectively, were fabricated. Properties of the WWCB samples, namely swelling, bending and compression strength were tested. 75 mm WWCB has higher fracture toughness but lower strength compared to 50 mm WWCB. Four types of wall systems with different type of configuration were produced and the test results were compared focusing on their value of ultimate load and failure mode. Walls that constructed without application of link and plaster displayed the poorest performance. Plastered and linked wall had the highest ultimate load and comparable with other load bearing walls. The results suggested that walls constructed using WWCB reinforced with Kelempayan wood wool are suitable for load bearing as they exhibited comparable properties when compared to the other load bearing walls such as masonry and straw bale wall

Thermal treatment of wood using vegetable oils: a review

Wood is an ideal building material as it is renewable and green. However, low dimensional stability and durability might restrict its usage in structural application. Therefore, modification is needed to improve the aforementioned issues. As an environmentally friendly wood modification method, heat treatment of wood using oil as a heating medium has brought to researcher’s attention to the fact that it might serve as an excellent treatment procedure in treating wood. This paper presents a review about the effects of oil heat treatment on the properties of wood such as colour stability, dimensional stability, mechanical strength and durability against termites and fungi as well as its potential to be used as construction and building materials. The pros and cons of using oil as a heating medium in wood treatment are discussed. This review shows discrepancies between the treatment methods or procedures and its resultant findings. Moreover, the effectiveness of the treatment is governed by several factors such as the type of oils used and wood species. The objective of the present paper is to conduct a review of the published literatures regarding the properties of wood modified by oil heat treatment and the results obtained were compared systematically

Thermal treatment of wood using vegetable oils: a review

Wood is an ideal building material as it is renewable and green. However, low dimensional stability and durability might restrict its usage in structural application. Therefore, modification is needed to improve the aforementioned issues. As an environmentally friendly wood modification method, heat treatment of wood using oil as a heating medium has brought to researcher’s attention to the fact that it might serve as an excellent treatment procedure in treating wood. This paper presents a review about the effects of oil heat treatment on the properties of wood such as colour stability, dimensional stability, mechanical strength and durability against termites and fungi as well as its potential to be used as construction and building materials. The pros and cons of using oil as a heating medium in wood treatment are discussed. This review shows discrepancies between the treatment methods or procedures and its resultant findings. Moreover, the effectiveness of the treatment is governed by several factors such as the type of oils used and wood species. The objective of the present paper is to conduct a review of the published literatures regarding the properties of wood modified by oil heat treatment and the results obtained were compared systematically