Adhesion and bonding properties of low molecular weight phenol formaldehyde-treated plybamboo

This study investigated the adhesion of bamboo (Gigantochloa scortechinii) strips after impregnation with phenolic resin and the effect of curing time on bonding properties of low molecular weight phenol formaldehyde (LMwPF)-treated plybamboo. The optimum pressing time to produce LMwPF-treated plybamboo was also determined. Properties studied included wettablity, buffering capacity, shear strength and wood failure. The study showed that phenolic-treated strips had higher contact angle and, thus, were more difficult to be penetrated by liquid compared with untreated strips. Buffering capacity showed that bamboo strip was stable towards acid. Shear bond strength of the plybamboo met the requirement of BS EN 314-1. The study concluded that the optimum pressing times were 22 and 33 min for three- and five-ply plybamboo respectively to produce good glue joints

Optimization of admixture and three-layer particleboard made from oil palm empty fruit bunch and rubberwood clones

Empty fruit bunch (EFB) is a biomass that is widely available and has the potential to be used as industrial raw material especially in wood-based industries. This study focuses on producing a particleboard by incorporating EFB with two different rubberwood clones: Prang Besar (PB) 260 and RRIM 2002, respectively. PB 260 is a commercially planted clone and wood from matured (>25 year-old) trees are used by wood-based panel manufacturers. RRIM 2002 is a new clone planted at the Malaysian Rubber Board (MRB) research trial plots and consists of only 4-year-old trees. Two types of particleboards (admixture and three-layer) with different ratios were produced. The Japanese Industrial Standard (JIS-5908 2003 particleboard) was used to evaluate mechanical and dimensional stability properties of the particleboards. From the study, it was found that admixture particleboards showed superior properties compared to three-layer particleboards. Layering EFB and rubberwood significantly decreased board performance for all properties (except internal bonding). The optimum ratios of EFB and both rubberwood clones are found to be 1:1 (50% EFB: 50% rubberwood). Meanwhile, increasing the rubberwood clones ratio to 70% lowered board performance especially for EFB (30%):RRIM 2002 clone (70%) boards which showed the lowest values for all properties for both admixture and three-layer board

Enhancing mechanical properties and dimensional stability of phenolic resin-treated plybamboo

This study evaluated the mechanical properties and dimensional stability of 3-ply phenolic-treated plybamboo influenced by treatment methods, namely, impregnation and soaking for 30, 60 and 90 min. Medium molecular weight phenol formaldehyde (MMwPF) resin with 1500 g mol-1 was applied to bamboo (Gigantochloa scortechinii) slivers of 2-mm thickness following resin treatments. The phenolic-treated bamboo slivers were precured at 60 °C for 6 hours, followed by hot pressing at 140 °C for 15 min to produce a 3-ply phenolic-treated plybamboo. Untreated boards were prepared using commercial phenol formaldehyde resin as binder. Use of MMwPF resin increased the density of boards. Modulus of rupture and impact resistance of the samples were significantly affected (p ≤ 0.01) by treatment methods but treatment duration did not show any significant effect. Reduced water absorption, thickness swelling and linear expansion suggested improved dimensional stability of the phenolic-treated sample. Treatment with phenolic resin markedly increased anti-shrinkage efficiency at p ≤ 0.05. Impregnation was more effective compared with soaking method