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Pengaruh Dimensi dan Pre-kompresi Kayu terhadap Sifat Penyerapan Air Dimensions and Pre-Compression Wood Influences on Water Absorption Lisman Suryanegara; Wahyu Dwianto
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 2, No 2 (2004): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

This research attempted to understand the effect of dimension and pre-compression on water absorption behavior of wood. Wood samples were water immersed at room temperature and 60°C for 48 hours in certain periods. Retention, weight gain and recovery level were observed.The results showed that water absorption mostly depended on radial and tangential area for un-compressed wood. For pre-compressed wood, the different of water immersion temperature caused recovery level differences. The retention of pre-compressed wood samples which 60°C water immersion for 48 hours were higher than that of un-compressed wood samples

Karakteristik LVL Lengkung dengan Proses Kempa Dingin Characteristic of LVL Bent by Cold Press Process Teguh Darmawan; Wahyu Dwianto; Yusup Amin; Kurnia Wiji Prasetyo; Bambang Subiyanto
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 7, No 2 (2009): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

Bending LVL (Laminated Veneer Lumber) is a more effisien method to manufacture bent wood components compare to other methods in raw materials point of view. The Bending LVL was made from Sengon veneers by cold press process with variation of Water Based Polymer-Isocyanate adhesive of 250, 280, 310 g/m2 and bend radius of 200,300, 400 mm. The results showed that the physical properties of Bending LVL made by using Water Based Polymer-Isocyanate adhesive and cold press process was fit with JAS 1639/1986 standard. The optimum adhesive concentration and bend radius was 250 g/m2 and 20 cm, respectively

Permanent Fixation of Radially Compressed Bamboo in Dry Condition by Heating and Its Mechanism Bambang Subiyanto; Wahyu Dwianto; Takashi Higashihara; Toshiro Morooka; Misato Norimoto
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 9, No 1 (2011): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

The stress-strain relationship and stress relaxation of oven-dried bamboo in radial compressed by heating were investigated. The effect of heating temperature and time on the weight loss, residual stress and strain recovery were also examined. The results indicated that the apparent of stress-strain curve (SS-curve) of Indonesian bamboo was different with Mousou bamboo and Sugi wood. The apparent SS-curve of Mousou bamboo was same as general SS-curve of wood under heating. The effect of heating temperature on yield stress of oven-dry bamboo had different results with the Sugi wood. The yield stress of bamboo decreased slightly up to heating temperature of 140 °C, then it was significantly decreased with increasing temperature. The decreasing yield stress of bamboo at heating temperature above 140 °C could be due to degradation or decomposition of existing extractive component and hemicelluloses in bamboo by heating. Time to achieve stress relaxation decreased with increasing heating temperature. The stress relaxation of bamboo was attained faster than that of Sugi wood. Tali bamboo had a fastest to attain stress relaxation than others type of bamboo. The residual stress and strain recovery decreased with decreasing weight loss. The most interesting finding was residual stress of Indonesian bamboo (Gombong and Tali bamboos) was attained zero and stress recovery less than 0.2 when the weight loss at about 4%.Key words: bamboo, permanent fixation, stress-strain.

Maximum Compression Level Measurement of Oil Palm Trunk Rudi Hartono; Imam Wahyudi; Fauzi Febrianto; Wahyu Dwianto
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 9, No 1 (2011): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

The objectives of this research were to study the density distribution and stress-strain curve (SSC) of oil palm trunk (OPT). The 40 year-old of OPT was used for these experiments. The specimen was taken from 1 m, 3 m and 5 m height of OPT with dimension of (2 x 2 x 2) cm3 for density distribution measurements. The interval of it was 2 cm from the outer near the bark to the inner near the center. The specimen for SSC measurements was taken only from 1 m height with the same dimension, interval, and position, as well. These specimens were treated into three conditions, i.e. air dry, wet and water saturated. The results showed that density of OPT was 0.23-0.74 g cm-3. The stress-strain curves showed that water saturated and wet conditions were easier to compress than that of air dried condition. The compression level increased from the outer to the center of the trunk. The center part can be compressed into 67% in air dry condition and 72-73% in wet and water saturated conditions from their initial thickness. Relationships between compression level, showing by strain, and density expressed as polynomial equations, regardless of the three conditions.Key words: compression, density distribution, OPT, SSC, vascular bundles

The Physical and Mechanical Properties of Branch Wood of Schizolobium amazonicumDucke Yusup Amin; Ika Wahyuni; Teguh Darmawan; Wahyu Dwianto; Sunarko Sunarko
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 9, No 2 (2011): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Masyarakat Peneliti Kayu Indonesia

One of the efficiency use of wood resources can be done by promoting the utilization of lesser-known species. However, high demand of familiar woods such as teak, kamper, meranti, mahoni, albizia, and acacia wood has limited the utilization of lesser-known species. The main purpose of this research was to determine the physical and mechanical properties of the branch-woodof Schizolobium amazonicum Ducke, one of lesser-known and a fast-growing species, and had recomonded its utilization. The physical and mechanical properties tested on this research were wood density, dimensional stability, Modulus of Elasticity (MOE), Modulus of Rupture (MOR), and compression strength parallel to grain. The sample testing refers to British Standard (BS 373, 1957). The result shows that the branch-wood of S.amazonicum has physical and mechanical properties as well as other fast-growing species, e.g. albizia wood. According to its density and MOR values, the S. amazonicum is classified as strength class of IV-III and it is possible used for light construction, furniture and plywood raw material.Key words: lesser known species, physical and mechanical properties, Schizolobiumamazonicum, strength class.

The Effect of Ultrasonication and Delignification Treatment on the Sugar Released Value of Wood Wahyuni, Ika; Adi, Danang Sudarwoko; Risanto, Lucky; Fitria, Fitria; Dwianto, Wahyu; Hartati, Sri; Kaida, Rumi; Hayashi, Takahisa
Wood Research Journal Vol 5, No 2 (2014): Wood Research Journal
Publisher : Masyarakat Peneliti Kayu Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51850/wrj.2014.5.2.37-45

The objective of these research was to study the impact of ultrasonication and delignification pretreatments in several wood species on their easiness for enzymatic hydrolysis, having the potential to be developed as the feedstocks for bioethanol production. Four different wood species from three botanical gardens in Indonesia have been selected, i.e., Gymnostoma sumatranum, Firmiana malayana, Pterocarpus indicus, and Alstonia scholaris, due to their higher sugar released values than a fast-grown tree, Sengon (Paraserianthes falcataria), when all were directly enzymatically hydrolyzed without pretreatment. The sugar released values after ultrasonication and enzymatic hydrolysis were between 3 – 5.5 mg/100 mg wood meal. When delignification pretreatment was performed, the sugar released values were higher than those with ultrasonication, ranging between 4 – 10.2 mg/100 mg wood meal. All the sugar released values after pretreatment were higher than those without pretreatment. Gymnostoma sumatranum was selected as the most potential wood species in this study due to its consistency among the species producing highest sugar released across different treatments. The SEM results showed that there was no significant changes in the morphological structure of the untreated fiber before and after enzymatic saccharification since it still had a complex structure due to the high lignin content. However, after the delignification treatment, the surface morphology of the fiber showed a decrease in the number of pits of the fiber, the surface residual of pits were reduced, parallel lines were more clearly visible, and the fiber structure was damaged with more small holes presented. The surface morphology of the fiber from the wood powder having delignification pretreatment supports the sugar released values which shows that the these values were higher than other treatments due to more recalcitrant substances were degraded, making it was easier for enzymes to break down cellulose. After ultrasonication, the SEM result showed less disrupted cell wall compared to after delignification which confirmed the higher sugar released data with delignification.

The Effect of Ultrasonication and Delignification Treatment on the Sugar Released Value of Wood Wahyuni, Ika; Adi, Danang Sudarwoko; Risanto, Lucky; Fitria, Fitria; Dwianto, Wahyu; Hartati, Sri; Kaida, Rumi; Hayashi, Takahisa
Wood Research Journal Vol 5, No 2 (2014): Wood Research Journal
Publisher : Masyarakat Peneliti Kayu Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51850/wrj.2014.5.2.37-45

The objective of these research was to study the impact of ultrasonication and delignification pretreatments in several wood species on their easiness for enzymatic hydrolysis, having the potential to be developed as the feedstocks for bioethanol production. Four different wood species from three botanical gardens in Indonesia have been selected, i.e., Gymnostoma sumatranum, Firmiana malayana, Pterocarpus indicus, and Alstonia scholaris, due to their higher sugar released values than a fast-grown tree, Sengon (Paraserianthes falcataria), when all were directly enzymatically hydrolyzed without pretreatment. The sugar released values after ultrasonication and enzymatic hydrolysis were between 3 – 5.5 mg/100 mg wood meal. When delignification pretreatment was performed, the sugar released values were higher than those with ultrasonication, ranging between 4 – 10.2 mg/100 mg wood meal. All the sugar released values after pretreatment were higher than those without pretreatment. Gymnostoma sumatranum was selected as the most potential wood species in this study due to its consistency among the species producing highest sugar released across different treatments. The SEM results showed that there was no significant changes in the morphological structure of the untreated fiber before and after enzymatic saccharification since it still had a complex structure due to the high lignin content. However, after the delignification treatment, the surface morphology of the fiber showed a decrease in the number of pits of the fiber, the surface residual of pits were reduced, parallel lines were more clearly visible, and the fiber structure was damaged with more small holes presented. The surface morphology of the fiber from the wood powder having delignification pretreatment supports the sugar released values which shows that the these values were higher than other treatments due to more recalcitrant substances were degraded, making it was easier for enzymes to break down cellulose. After ultrasonication, the SEM result showed less disrupted cell wall compared to after delignification which confirmed the higher sugar released data with delignification.

IDENTIFICATION OF LIGNOCELLULOSE-LIKE MATERIAL USING SPECTROSCOPY ANALYSIS Adi, Danang Sudarwoko; Fatriasari, Widya; Narto; Triwibowo, Dimas; Darmawan, Teguh; Amin, Yusup; Sofianto, Imran Arra'd; Pari, Rohmah; Agustiningrum, Dyah Ayu; Rahmanto, Raden Gunawan Hadi; Dewi, Listya Mustika; Himmi, Setiawan Khoirul; Djarwanto; Damayanti, Ratih; Dwianto, Wahyu
Indonesian Journal of Forestry Research Vol. 11 No. 2 (2024): Indonesian Journal of Forestry Research
Publisher : Association of Indonesian Forestry and Environment Researchers and Technicians

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59465/ijfr.2024.11.2.299-306

Lignocellulose materials, such as bamboo, rattan, and wood, have been largely used for furniture and crafts. On the other hand, the utilization of lignocellulose-like materials, which have a similar texture and appearance to those from nature, has been increasing recently due to their superior durability. This research aimed to identify the lignocellulose-like material using spectroscopy analysis, such as Raman and Near Infrared (NIR) which is well-known as a non-destructive, quick, and accurate approach for material identification. We investigated 4 types of lignocellulose-like materials that were provided by Dewan Serat Indonesia (The Indonesian Fiber Council) from an industry that produces them. The NIR analysis was performed at wavenumbers 10,000-4,000 cm-1. The natural lignocellulose (bamboo and wood) and the polymers (polyethylene and polyproline) were used as standards. Raman analysis was further employed to identify the composition of selected lignocellulose-like materials by comparing their spectra with the library software. The results showed that the original NIR spectra of lignocellulose-like and those natural materials were different, indicating that the NIR analysis can differentiate those materials. The NIR spectra of lignocellulose-like materials were similar to those of polyethylene spectra. Those lignocellulose-like were also identified as polyethylene due to the similarity of the Raman spectra and their library spectra.

CENTRAL KALIMANTAN’S FAST GROWING SPECIES: SUITABILITY FOR PULP AND PAPER Adi, Danang Sudarwoko; Wahyuni, Ika; Risanto, Lucky; Rulliaty, Sri; Hermiati, Euis; Dwianto, Wahyu; Watanabe, Takashi
Indonesian Journal of Forestry Research Vol. 2 No. 1 (2015): Indonesian Journal of Forestry Research
Publisher : Association of Indonesian Forestry and Environment Researchers and Technicians

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59465/ijfr.2015.2.1.21-29

Recent studies of fast growing species grown in PT. Sari Bumi Kusuma, Central Kalimantan, show that based on their fiber dimensions there are five species, namely Endospermum diadenum, Dillenia spp., Adinandra dumosa, Adiandra sp., and Nauclea junghuhnii with good potential for pulp and paper production. The fiber length of those five wood species are was more than 2,200 µm on average. This paper studies the physical properties, fiber dimensions and their chemical contents to predict the paper and pulp quality. The result shows that all of the species were classified in the medium to high density category. All species were classified into the first class quality for pulp and paper. Based on chemical contents, Dillenia sp. is the most suitable species due to its high value of holocellulose and a-cellulose, low lignin content, and its fiber length is about 3,119 µm on average. A. dumosa also has good opportunities because it had the longest fiber lengths (3,137 µm on average) and high value of holocellulose, even though it has the highest lignin content. While Nuclea junghuhnii is less suitable due to low values of holocellulose and a-cellulose.

THE SURFACE CHARACTERISTICS AND PHYSICAL PROPERTIES OF SENGON WOOD AT HIGH-TEMPERATURE HEATING TREATMENTS Fariha, Tushliha Ayyuni; Marbun, Sari D; Sudarmanto; Narto; Bahanawan, Adik; Sejati, Prabu S; Darmawan, Teguh; Triwibowo, Dimas; Adi, Danang S; Amin, Yusup; Augustina, Sarah; Dwianto, Wahyu; Sari, Rita K; Alipraja, Irsan; Wahyudi, Imam; Kusuma, EM. Latif R
Indonesian Journal of Forestry Research Vol. 12 No. 1 (2025): Indonesian Journal of Forestry Research
Publisher : Association of Indonesian Forestry and Environment Researchers and Technicians

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59465/ijfr.2025.12.1.135-149

Sengon (Falcataria moluccana Miq.) is a fast-growing timber species widely distributed in Indonesia. However, its dimensional instability and low surface quality have limited its widespread use. Wood modification is essential for enhancing these properties, and one effective approach is heat treatment. This study investigated the effects of different heat treatment methods and durations on color change, surface roughness, weight loss (WL), decreased density, and dimensional stability of sengon wood. The heat modification process was conducted using two methods: oven-heating and hot press-heating, with temperatures set at 200°C for durations ranging from 1 to 5 hours. The results indicated that oven-heated samples exhibited higher surface roughness, weight loss, density reduction, and dimensional stability while showing less color change than hot press-heated samples. Additionally, the hot press-heated samples displayed more significant color changes (darkening) and smoother surface roughness. WL and decreased density were also more pronounced with longer heating durations, except for the 4- and 5-hour hot press-heating treatments. Notably, oven-heated samples demonstrated higher dimensional stability than hot press-heated samples as the duration of heating increased. Based on the results, the optimal treatment varies depending on the desired product characteristics. For improved surface qualities with consideration of WL, the optimum treatment is a 2-hour hot press-heating treatment. Higher dimensional stability can be achieved through a 3-hour oven-heating treatment.

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