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.

Quality Improvement of Oil Palm Trunk Properties by Close System Compression Method

Rudi Hartono,Imam Wahyudi,Fauzi Febrianto,Wahyu Dwianto,Wahyu Hidayat,Jae-hyuk Jang,Seung-hwan Lee,Se-hwi Park,Nam-hun Kim 한국목재공학회 2016 목재공학 Vol.44 No.2

Densification of the inner part of oil palm trunk (OPT) by the close system compression (CSC) method was performed in this study. The effects of the compression temperature and time on the anatomical, physical andmechanical properties of OPT were evaluated. The inner part of OPT with an initial average density of 0.3 g/cm3 was used as samples. Oven-dried samples were immersed in water and vacuumed until fully saturated and then compressed by CSC at 120, 140, 160 or 180℃ for 10, 20, 30 or 40 min. The anatomical characteristics of transverse and radial sections before and after compression were compared by optical microscopy. The physical and mechanical properties, including the density, recovery of set (RS), modulus of elasticity (MOE), modulus of rupture (MOR), and compression parallel to grain were examined. It was observed that the anatomical characteristic of the inner part of OPT (i.e., vascular bundles, vessels, and parenchyma tissue) became flattened, fractured, and collapsed after compression by CSC. The RS decreased with increasing compression temperature and time. The lower RS indicated high dimensional stability. The physical and mechanical properties (i.e., density, MOR, MOE, and compressive strength) of the inner part of OPT increased with increasing compression temperature and time. Compression by the CSC method at 160℃ for 40 min was the optimum treatment.

Analysis on Wood Quality, Geometry Factor, and Their Effects on Lathe Check of Samama (Anthocephalus macrophyllus) Veneer

Tekat Dwi Cahono,Imam Wahyudi,Trisna Priadi,Fauzi Febrianto,Effendi Tri Bahtiar,Eka Novriyanti 한국목재공학회 2016 목재공학 Vol.44 No.6

Relatively little information is available regarding the correlation between wood and veneer quality, especially for Samama wood, an endemic wood species in eastern Indonesia. This study addresses the quality of 8 years old Samama wood and its effect on the veneer quality. Samama wood quality was determined by evaluating its specific gravity, moisture content, fiber dimensions, and microfibril angle from pith toward bark. Meanwhile, veneer quality was assessed by examining veneer thickness and lathe check characteristics. Geometry factor model was constructed to elaborate the quantities of lathe check from pith toward bark. Results show that fair variations of veneer thickness, ranging from 1.5 mm to 3.0 mm, could be obtained from Samama wood. The quantity, depth, and length of lathe check were noticeably decreasing toward bark. Further, in the same manufacturing process, geometry factor was determined as the dominant factor over other wood properties in affecting the frequency of lathe checks from pith towards bark. These facts should be put into consideration in producing veneer from Samama wood. Moreover, these results enlighten the potential of Samama wood as plywood and other excellent veneer-based products.

Investigating the Anatomical and Physical-Mechanical Properties of the 8-Year-Old Superior Teakwood Planted in Muna Island, Indonesia

( Alvin Muhammad Savero ),( Imam Wahyudi ),( Istie Sekartining Rahayu ),( Andi Detti Yunianti ),( Futoshi Ishiguri ) 한국목재공학회 2020 목재공학 Vol.48 No.5

Muna teakwood, especially from old stands, has been popular as raw material for timber industries in Indonesia for the past ten decades. Due to the scarcity of this wood, superior-grown seedlings of Muna teakwood have been developed and widely planted. Since there is no information on its characteristics, therefore, the aim of this research was to investigate wood characteristics of the 8-year-old superior-grown teak from Muna Island to ensure their proper utilization as raw material for wooden furniture. Wood discs and boards from basal area of three different trees were used as the samples. Macroscopic and microscopic anatomical characteristics were observed following the IAWA's list, while their physicalmechanical properties were measured following British Standard 373-57. Results showed that anatomical characteristics of this wood sample are similar to regular teakwood, but its heartwood portion is higher. Differences among trees are found in regards to wood texture, growth ring width, as well as early and latewood portion. The green moisture content was lower than that of fast-growing teak of a similar age. The wood is more stable than the old teakwood, but its specific gravity is lower. In general, mechanical properties of this wood were higher than those of the regular fast-growing teakwood, but lower than the old one. Based on its specific gravity, this superior Muna teakwood was categorized as a Strength Class of III. The wood is suitable enough for wooden furniture manufacturing.

Morphological and Anatomical Evaluation of Grafted Pinus

Arida Susilowati,Apri Heri Imam Wahyudi,Supriyanto,Iskandar Z Siregar 한국목재공학회 2016 목재공학 Vol.44 No.6

Morphological and anatomical evaluation of grafted P. merkusii have been undertaken to obtain the information about compatible and incompatible symptoms of 18 years old grafts based on morphological observation and microscopic analysis. Samples of compatible and incompatible grafts were obtained from previous research conducted by the Silviculture Departement Team in 1994. Result showed that compatible grafts have normal stem form and secondary growth (diameter growth), but some abnormality symptoms like undulated pattern of annual growth rings, phloem thickening and abnormality resin ducts in inner and middle parts of the union area occurred. Incompatible ones showed abnormality of the stem form, cortex-bark necrosis and swelling in the union area. Microscopic observation showed abnormality of all parts of the union, undulated pattern of annual growth rings, phloem thickening, abnormal resin ducts, low numbers and discontinuity of vascular elements in the union area.

Effect of Phenol Formaldehyde Impregnation on The Physical and Mechanical Properties of Soft-Inner Part of Oil Palm Trunk

Rudi Hartono,Wahyu Hidayat,Imam Wahyudi,Fauzi Febrianto,Wahyu Dwianto,Jae Hyuk Jang,Nam Hun Kim 한국목재공학회 2016 목재공학 Vol.44 No.6

The objective of this study was to improve physical and mechanical properties of soft-inner part of oil palm trunk (S-OPT) after impregnation with phenol formaldehyde (PF) resin and densification by close system compression (CSC) method. Effect of different methods of PF resin impregnation (i.e., no vacuum-pressure, vacuum, and vacuum-pressure) was evaluated. The results showed that PF resin impregnation and CSC significantly improved the physical and mechanical properties of S-OPT up to: (1) 176% in density; (2) 309% in modulus of rupture (MOR); (3) 287% modulus of elasticity (MOE); and (4) 191% in the compressive strength. Physical and mechanical properties of S-OPT showed their best performances when PF resin impregnated with vacuum- pressure method as shown by higher weight gain, density, MOR, MOE, compressive strength, and lower recovery of set due to better penetration of PF resin into S-OPT. Combining PF resin impregnation and densification by CSC method could be a good method to improve physical and mechanical properties of S-OPT.

Anatomical Structures and Fiber Quality of Four Lesser-Used Wood Species Grown in Indonesia

( Sari Delviana MARBUN ),( Imam WAHYUDI ),( Jajang SURYANA ),( Deded Sarip NAWAWI ) 한국목재공학회 2019 목재공학 Vol.47 No.5

This study aimed to investigate the anatomical structure and fiber quality of four lesser-used wood species namely Benuang (O. sumatrana), Duabanga (D. moluccana), Pisang Merah (H. hellwigii), and Terap (A. odoratissimus). This study evaluated its suitability for raw material in pulp and paper manufacturing. The anatomical structure was observed macro- and microscopically. Macroscopic structures were observed directly to the wood samples, while microscopic characteristics were observed through microtome specimens. Fiber dimension was measured through macerated specimens and fiber quality was analyzed following the Rachman and Siagian’s method. Results showed that these four timber species have similarity in the indistinct growth ring, diffuse porous in a radial pattern, rounded solitary vessel outline, 1 to 3 cells of ray width, deposits within the rays, fiber length, and cell wall thickness. Differences were found on vessel diameter, vessel grouping, vessel frequency, tyloses existence, type of axial parenchyma, and ray height. Based on fiber length and its derived values, the wood fibers of all species studied are suitable for pulp and paper manufacturing. They belong to the II quality class. The produced pulp and paper would have good quality, especially in tensile, folding, and tear strength. To promote their utilization, silviculture aspect of these four species has to be well understood.