Radial Variation in Selected Wood Properties of Indonesian Merkusii Pine

( Wayan Darmawan ),( Dodi Nandika ),( Britty Datin Hasna Afaf ),( Istie Rahayu ),( Dumasari Lumongga ) 한국목재공학회 2018 목재공학 Vol.46 No.4

Merkusii pine wood (Pinus merkusii) was extensively planted throughout Indonesia, where it is only indigenous in northern Sumatera, by the Dutch during colonial times. The demand for this wood species, especially in the domestic market, has increased notably, despite its limited durability regarding decay resistance. The purpose of this study was to investigate the occurrence of juvenile and mature wood on merkusii pine and to analyze its radial features from pith to bark based on density, shrinkage, static bending in modulus of rupture and modulus of elasticity, fiber length, microfibril angle, and durability. A segmented modeling approach was used to find the juvenile-mature transition. The graveyard test was performed to characterize the termite resistance from pith to bark of merkusii pine. The maturations were estimated to start at radial increments of 15 cm from the pith by fiber length and of 12 cm from the pith by microfibril angle. The projected figures for the proportion of juvenile wood at breast height were around 65%. The results also indicate that the pine wood was 0.52 g/㎤ in density, 1.45 in coefficient of anisotropy, which indicates its good stability, 7597 MPa in modulus of elasticity, and 63 MPa in modulus of rupture. Natural durability against subterranean termite of the merkusii pine wood was rated to be grade 4 to 0 from pith to bark. However, after being treated by Entiblu and Enborer preservatives, its rating increased to grade 10 to 9.

< 구두-E-06 > Performance of LVL samama (Anthocephalus macrophyllus) based on thickness, juvenile proportion and veneer lay-up

( Tekat Dwi Cahyono ),( Wayan Darmawan ),( Eka Novriyanti ) 한국목재공학회 2018 한국목재공학회 학술발표논문집 Vol.2018 No.1

A study to determine the quality of laminated veneer lumber (LVL) from samama wood (Anthocephalus macrophyllus) was carried out. Samama is a fast growing endemic wood in the eastern Indonesia. Factorial of 3 factors in RAL design was used to investigate the influence of veneer thickness, juvenile proportion and veneer lay-up to the quality of the resulted LVL samama. The veneer thicknesses were 1.5 mm and 3.0 mm. Juvenile proportions were arranged in 5 levels which were 100% of juvenile veneer, 100% of mature veneer, and combination of both juvenile and mature with juvenile proportion of 14%, 43% and 71%. Two veneer lay-up used in this study were loose side met loose side and tight side met loose side. The result of the study showed the vary density of LVL by the different proportion of juvenile and veneer thickness. This factor also affected the other physical traits. Shear strength of the LVL was equal with the wood, yet MOE and MOR were affected by juvenile proportion and veneer lay-up. LVL developed from 100% of mature veneer gave the best mark of MOE and MOR, although there was no significant difference in quality with the other tested juvenile proportions.

Flexural Properties of Heat-Treatment Samama (Anthocephalus macrophyllus) Wood Impregnated by Boron and Methyl Metacrylate

( Tekat Dwi Cahyono ),( Wayan Darmawan ),( Trisna Priadi ),( Apri Heri Iswanto ) 한국목재공학회 2020 목재공학 Vol.48 No.1

This study was conducted to analyze the application of boron compounds, methyl methacrylate (MMA), and heat treatment (HT) on changes in the density, moisture content, and flexural properties of samama (Anthocephalus macrophyllus) wood. Samama wood was impregnated with borax (BX) and boric acid (BA) using a pressure method at 5 atm for 4 h. Afterwards, the wood was impregnated with MMA at the same pressure and duration. Finally, the samama wood was given HT at 90 ºC and 180 ºC. The results indicate that there was a weight gain of 93.4% in the wood impregnated using BA and MMA monomer and HT at 90 °C. Consequently, the wood’s density increased by 82.3%. Increased MOE and MOR percentages of 32.2% and 29.4%, respectively, were also found. HT at 180 °C degraded the wood components and MMA, and consequently, the density, MOE, and MOR also decreased. The wood impregnated by BX, BA, and MMA, and subjected to HT also had decreased moisture content (MC). This research recommends that the application of boron (BX, BA) should be combined with an MMA monomer and HT at 90 °C as an alternative method to improve samama wood quality. If darker color is preferable, HT should be conducted at 180 °C.

Specific Gravity and Dimensional Stability of Boron-Densified Wood on Three Lesser-Used Species from Indonesia

( Sarah Augustina ),( Imam Wahyudi ),( I Wayan Darmawan ),( Jamaludin Malik ),( Efrida Basri ),( Yoichi Kojima ) 한국목재공학회 2020 목재공학 Vol.48 No.4

Effect of pre-treatment and compression ratio on specific gravity (SG) and dimensional stability improvement of three lesser-used wood species from natural forest area of North Kalimantan Province, Indonesia had been investigated. Hot soaking at 80 ℃ for 3 hours within 2 and 5% of boron solution was applied as pre-treatment, while compression ratio applied was 20 and 40% from the initial thickness. Densification was conducted using hot pressing machine at 30 kg/cm² of pressure and 160 ℃ of temperature for 15 minutes. Specific gravity was measured gravimetrically, while dimensional stability was evaluated through thickness swelling and water absorption as the indicator. Results show that SG of densified wood was influenced by wood species and compression ratio, but not by pre-treatment applied; while dimensional stability was influenced by wood species, compression ratio, and pre-treatment. Specific gravity and water absorption of densified wood was improved significantly. Specific gravity increased 28.86-63.03%, while water absorption decreased 12.80-15.89%. Thickness swelling of 20% densified wood was lower than that of 40% densified wood.

Physicomechanical Properties Enhancement of Fast-Growing Wood Impregnated with Wood Vinegar Animal Adhesive

( Efrida Basri ),( Saefudin ),( Mahdi Mubarok ),( Wayan Darmawan ),( Jamal Balfas ),( Yelin Adalina ),( Yusuf Sudo Hadi ) 한국목재공학회 2023 목재공학 Vol.51 No.6

This study is a continuation of our previous work, which focused on the resistance of jabon wood to termites after impregnation with wood vinegar (WV) and animal-based adhesive (kak). This paper presents the physicomechanical properties of fast-growing jabon wood impregnated with kak at two concentrations (8% and 10%) in wood vinegar or water as a solvent with and without 4% borax. The physical properties of the impregnation solution, that is, viscosity, density, pH, and solid content, were evaluated according to SNI 06-4567-1998. Some physical parameters, such as weight percent gain (WPG), density, water uptake, anti-swelling efficiency (ASE), crystallinity, and mechanical properties, i.e., modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS), of the impregnated wood were determined. Based on these results, wood impregnated using a mixture of kak in WV presented better physical (increased WPG, density, dimensional stability, and crystallinity) and mechanical (increased MOE/MOR and compression strength) properties than wood impregnated with a water solvent or untreated wood. The wood impregnated using WV and water solvent improved the physical and mechanical properties. The density of the wood increased by 44%-58% and 32%-47%, ASE radial-tangential increased by 38%-45%; 15%-28% after 24 h of water immersion, crystallinity increased by 59%-74%; 36%, MOE increased by 46%- 57%; 28%-31%, MOR increased by 29%-34%; 14%-27%, and compression strength increased by 40%-76%; 38%-72% values to untreated wood.

Characteristics of Magnetic Sengon Wood Impregnated with Nano Fe3O4 and Furfuryl Alcohol

Gilang Dwi LAKSONO,Istie Sekartining RAHAYU,Lina KARLINASARI,Wayan Darmawan,Esti PRIHATINI 한국목재공학회 2023 목재공학 Vol.51 No.1

Sengon (Falcataria moluccana Miq.) tree offers a wood of low quality and durability owing to its low density and thin cell walls. This study aimed to improve the properties of sengon wood by making the wood magnetic, producing new functions, and characterizing magnetic sengon wood. Each wood sample was treated using one of the following impregnation solutions: Untreated, 7.5% nano magnetite-furfuryl alcohol (Fe3O4-FA), 10% nano Fe3O4-FA, and 12.5% nano Fe3O4-FA. The impregnation process began with vacuum treatment at 0.5 bar for 2 h, followed by applying a pressure of 1 bar for 2 h. The samples were then tested for dimensional stability and density and characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM–EDX), Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) analysis, and vibrating sample magnetometry (VSM) analysis. The results showed that the Fe3O4-FA impregnation treatment considerable affected the dimensional stability, measured in terms of weight percent gain, anti-swelling efficiency, water uptake, and bulking effect, as well as the density of sengon wood. Changes in wood morphology were detected by the presence of Fe deposits in the cell walls and cell cavities of the wood using SEM–EDX analysis. XRD and FTIR analyses showed the appearance of magnetite peaks in the diffractogram and Fe-O functional groups. Based on the VSM analysis, treated sengon wood is classified as a superparamagnetic material with soft magnetic properties. Overall, 10% Fe3O4-FA treatment led to the highest increase in dimensional stability and density of sengon wood.

Improvement of Fast-Growing Wood Species Characteristics by MEG and Nano SiO₂ Impregnation

( Fitria Cita Dirna ),( Istie Rahayu ),( Lukmanul Hakim Zaini ),( Wayan Darmawan ),( Esti Prihatini ) 한국목재공학회 2020 목재공학 Vol.48 No.1

Jabon (Anthocephalus cadamba) is a fast-growing wood species that is widely utilized for light construction and other purposes in Indonesia. The objectives of the current study were to determine the effects of monoethylene glycol (MEG) and SiO₂ nanoparticles (nano SiO₂) impregnation treatment on the dimensional stability and density of jabon wood and to identify the characteristics of impregnated jabon wood. Wood samples were immersed in water (as untreated), MEG, 0.5% MEGSiO₂, then impregnated by applying 0.5 bar of vacuum for 60 min, and then applying 2.5 bar of pressure for 120 min. The results showed that impregnation with MEG and Nano SiO₂ had a significant effect on the dimensional stability of jabon wood. Polymers can fill cell walls in wood indicated by increasing weight percentgain, antiswelling efficiency, bulking effect, and density, then decreasing in water uptake value. Jabon wood morphology by using SEM showed that MEG SiO₂ polymers can cover part of the pitsin the wood vessel wall of jabon. This finding was reinforced by EDX results showing that the silicon content was increased due to the addition of SiO₂ nano. The XRD diffraction pattern indicated that MEG SiO₂ treatment increased the degree of crystallinity in wood samples. Overall, treatment with 0.5% MEG SiO₂ led to the most improvement in the dimensional stability of 5-year-old jabon wood in this study.