Articles

DEVELOPMENT OF DRYING SCHEDULE OF SUPERIOR AND CONVENTIONAL TEAK WOOD OF TEN YEARS-OLD PLANTED IN BLORA, CENTRAL JAVA Listyanto, Tomy; Darmawan, Yusuf Setia; Pujiarti, Rini; Hidayati, Fanny; Lukmandaru, Ganis; Sulistyo, Joko
Jurnal Ilmu Kehutanan Vol 10, No 1 (2016)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (207.176 KB) | DOI: 10.22146/jik.12633

Abstract

The aims of this study were to investigate drying defect characteristics, to develop proper drying schedule, and to analyze the relationship between the developed drying schedule and its wood properties. This study used superior and conventional teak wood of ten years-old planted in Blora, Central Java. Sample from different axial positions (bottom and middle part) and different board thicknesses (20 mm and 40 mm) were taken. Drying schedule was developed in accordance to Terazawa method, which dried the sample for 72 h at a temperature of 100 °C. Initial moisture content, crack, collapse, and honeycombing were observed to determine the proper drying schedule. The developed drying schedule then was related to their characteristics, such origin of the seedling, thickness, density, and heartwood percentage. The proper scheduled was also applied in larger sample and evaluated. The results showed that there were five variations of drying schedule for superior and conventional teak wood. Chi square analysis indicated that the board thickness affect significantly on developing drying schedules. Boards with a thickness of 20 mm can be dried with an initial temperature of 70 °C, the wet bulb depression 7°C, and the final temperature of 105°C. Further, boards with a thickness of 40 mm should be dried with a softer drying schedule with an initial temperature of 60°C, wet bulb depression temperature of 4 °C, and the final temperature of 85°C. Application of the selected drying schedule was succeed without any significant defects.Keywords: superior; teak; drying schedules; inferior; wood Pengembangan Skedul Pengeringan Kayu Jati "Mega" dan Konvensional Umur 10 tahun Ditanam di Blora, Jawa tengahAbstractTujuan dari penelitian ini adalah mengetahui karakteristik cacat pengeringan, skedul pengeringan yang sesuai, variasi ketebalan papan serta beberapa sifat kayunya terhadap skedul pengeringan. Penelitian ini menggunakan kayu jati prospektif unggul dan konvensional umur 10 tahun dari Blora, Jawa Tengah dengan letak aksial yang berbeda (pangkal dan tengah) serta ketebalan papan masing-masing 20 mm dan 40 mm. Penyusunan skedul pengeringan menurut metode Terazawa, dengan pengeringan selama 72 jam pada suhu 100°C. Parameter yang diamati yaitu kadar air awal, cacat retak, kolaps, dan honeycombing. Cacat yang terjadi digunakan untuk penyusunan skedul pengeringan. Skedul pengeringan selanjutnya diuji hubungannya dengan sumber asal bibit, ketebalan, berat jenis, dan persen kayu terasnya. Skedul pengeringan yang paling sesuai selanjutnya diujicoba dan dievaluasi. Berdasarkan hasil penelitian, diajukan lima skedul pengeringan. Hasil analisis chi square menunjukkan bahwa ketebalan papan memiliki hubungan signifikan terhadap variasi skedul pengeringan. Papan dengan ketebalan 2 cm dapat dikeringkan dengan suhu awal 70°C, depresiasi bola basah 7°C, dan suhu akhir 105°C. Selanjutnya, papan dengan ketebalan 4 cm perlu dikeringkan dengan skedul yang lebih lunak dengan suhu awal 60°C, depresiasi suhu bola basah 4°C, dan suhu akhir 85°C. Hasil uji aplikasi menunjukkan hasil yang memuaskan dengan cacat yang tidak signifikan. 
STUDI MUTU KAYU JATI DI HUTAN RAKYAT GUNUNGKIDUL IV. SIFAT MEKANIKA KAYU Marsoem, Sri Nugroho; Prasetyo, Vendy Eko; Sulistyo, Joko; Sudaryono, Sudaryono; Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 9, No 2 (2015)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (232.477 KB) | DOI: 10.22146/jik.10197

Abstract

Sifat mekanika dari kayu gergajian adalah persyaratan terpenting dalam banyak penerapan khususnya untuk keperluan konstruksi. Paper ini merupakan lanjutan dari penelitian sifat fisika kayu di tiga tempat tumbuh (Panggang, Playen, Nglipar) hutan rakyat Kabupaten Gunungkidul. Pengujian sifat mekanika dilakukan mengacu pada British Standards 373:57. Hasil penelitian menunjukkan bahwa kayu yang diteliti termasuk dalam kelas kuat II-III. Dari perhitungan analisis varian, tempat tumbuh berpengaruh nyata pada modulus patah (MoR) keteguhan lengkung statik, keteguhan tekan tegak lurus serat maksimum, keteguhan geser, dan kekerasan. Secara keseluruhan, kecuali untuk nilai MoR, sampel kayu dari Nglipar memberikan nilai kekuatan yang lebih tinggi. Pengaruh arah aksial dan radial pohon secara umum tidak begitu terlihat pada semua parameter kekuatan kecuali di keteguhan belah. Meskipun berkorelasi secara linier, hanya korelasi moderat yang diamati dari hubungan sifat mekanika (MoR/keteguhan geser) dan kerapatan dasar. Tidak ada korelasi nyata antara kerapatan dasar dan modulus elastisitas keteguhan lengkung statik serta antara kerapatan dasar dan keteguhan tekan sejajar serat maksimum.Kata kunci: Tectona grandis, sifat mekanika, kerapatan dasar, hutan rakyat, Gunungkidul. A study of teak wood quality from community forests in Gunungkidul  IV. Mechanical PropertiesAbstractMechanical properties of sawn timber are the most important characteristics in many applications, particularly for structural timber. The previous paper in this series reported on the physical properties of teak trees at different sites (Panggang, Playen, Nglipar) from community forests in Gunungkidul regency. In this study, the mechanical properties were evaluated according to British Standards 373:57. The results showed that the timber were classified in the II-III of strength class. By analysis of variance, site factor affected the values of modulus of rupture (MoR) in statical bending strength, maximum compression perpendicular to grain strength, shear strength and hardness. In general, except for MoR, the wood samples from Nglipar gave higher strength levels. Except for cleavage strength, the effects of the axial and radial position of the tree on mechanical properties were mostly negligible. Although linearly related, only modest correlations were observed between the mechanical parameters (MoR/shear strength) and basic density. No significant correlation was found between the values of basic density and modulus of elasticity of static bending strength as well as between basic density and the strength of maximum compression parallel to grain.
SIFAT FISIKA MEKANIKA DAN KETAHANAN PAPAN PARTIKEL BAMBU DENGAN PEREKAT ASAM SITRAT TERHADAP SERANGAN RAYAP KAYU KERING Widyorini, Ragil; Yudha, Ari Puspa; Lukmandaru, Ganis; Prayitno, Tibertius Agus
Jurnal Ilmu Kehutanan Vol 9, No 1 (2015)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1071.221 KB) | DOI: 10.22146/jik.10180

Abstract

Penelitian mengenai penggunaan asam sitrat sebagai agen pengikat alami masih relatif sedikit. Oleh karena itu penelitian ini difokuskan pada pengaruh jumlah asam sitrat dan suhu pengempaan terhadap sifat papan partikel bambu, termasuk ketahanannya terhadap serangan rayap kayu kering. Bahan penelitian adalah partikel bambu petung. Komposisi kimia bahan baku bambu diuji untuk kadar ekstraktif, holoselulosa, lignin, dan alfa selulosa. Faktor pada penelitian ini adalah jumlah asam sitrat (0 - 40%) berdasarkan berat kering udara partikel) dan suhu pengempaan (200 oC dan 220 oC). Sifat fisika dan mekanika papan partikel diuji berdasarkan standar pengujian JIS A 5908. Analisis menggunakan Fourier transform infrared spectroscopy (FTIR) juga dilakukan untuk mengetahui perubahan gugus ester pada berbagai jumlah asam sitrat dan suhu pengempaan. Pengujian ketahanan terhadap serangan rayap kayu kering juga dilakukan dengan menghitung nilai pengurangan berat dan mortalitas rayap setelah 6 minggu. Hasil pengujian menunjukkan bahwa interaksi kedua faktor berpengaruh nyata terhadap nilai pengembangan tebal, penyerapan air, modulus elastisitas dan modulus patah. Intensitas gugus C=O yang ditunjukkan pada puncak 1720 cm-1 semakin bertambah besar seiiring dengan semakin banyaknya jumlah asam sitrat, yang menyebabkan kekuatan perekatan dan stabilitas dimensi papan partikel menjadi semakin kuat. Kondisi optimum pada penelitian ini adalah papan partikel dengan penambahan jumlah asam sitrat 20 % pada suhu pengempaan 200 oC dengan kualitas yang dapat memenuhi standar JIS A 5908 tipe 8. Penambahan asam sitrat dapat meningkatkan mortalitas rayap kayu kering secara nyata. Penambahan 20 % asam sitrat pada suhu pengempaan 200 oC menghasilkan nilai pengurangan berat 0,9 % dan mortalitas rayap 57 %.Kata kunci: bambu petung, asam sitrat, suhu pengempaan, jumlah asam sitrat. Mechanical properties and durability against the dry termite attacks of particleboard made from bamboo with citric acid as adhesive AbstractResearch on development of citric acid as natural adhesive are still limited. Therefore this research focused on effects of citric acid content and pressing temperature on properties of particleboard made from bamboo, including its durability to the dry termite attacks. Petung bamboo particles were used as raw materials. Chemical characteristics of petung bamboo were analyzed for its extractive, lignin, holocellulose and alpha cellulose. Factors used in this research were citric acid content (0 - 40 %) based on dry weight particles and pressing temperature (200 oC dan 220 oC). Properties of the particleboard were analyzed based on Japanese Industrial Standard (JIS) A 5908 for particleboard. Fourier transform infrared spectroscopy (FTIR) analysis was used for investigating the changes of ester groups at various citric acid content and pressing temperature. The dry termite resistance was then analyzed for its weight loss and mortality after 6 weeks. The results showed that interaction between two factors affected significantly on thickness swelling, water absorption, modulus of elasticity, and modulus of rupture. Intensity of C=O groups became stronger as increasing citric acid content, providing high mechanical properties and high dimensional stability. Optimum condition in this research was achieved at 20 % of citric acid content and 200 oC of pressing temperature, which the board properties met the requirement of JIS A 5908 type 8. Increasing of citric acid content would also increase the dry termite mortality. Addition of 20 % citric acid at 200 oC of pressing temperature produced particleboard with the weight loss was 0.9 % and 57 % of the dry termite mortality. 
STUDI MUTU KAYU JATI DI HUTAN RAKYAT GUNUNGKIDUL III. SIFAT FISIKA KAYU Marsoem, Sri Nugroho; Prasetyo, Vendy Eko; Sulistyo, Joko; Sudaryono, Sudaryono; Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 8, No 2 (2014)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (324.537 KB) | DOI: 10.22146/jik.10162

Abstract

Penelitian ini bertujuan untuk mengetahui variasi sifat fisika kayu dari pohon jati yang tumbuh di 3 tempat berbeda (Panggang, Playen, Nglipar) hutan rakyat di kabupaten Gunungkidul. Parameter yang diukur adalah kadar air segar (KAS), kerapatan dasar (KD), dan penyusutan linier maupun volumetrik. Sebanyak 3 pohon di tiap lokasi ditebang kemudian tiap pohon dibagi menjadi 3 potongan di posisi aksial yaitu pangkal, tengah, dan ujung. Tiap potongan tersebut kemudian dibagi 3 dalam posisi radial yaitu dekat hati, tengah, dan dekat kulit. Kisaran nilai KD dan KAS adalah 504-672 kg/cm3 dan 47-125%, secara berturutan. Hasil analisis keragaman menunjukkan sampel Playen bagian ujung cenderung memberikan nilai rerata KD lebih tinggi demikian juga bagian dekat kulit pada arah radial. Sampel Nglipar memberikan nilai kisaran KAS paling rendah (47-70%) sedangkan pada posisi radial nilai rerata tertinggi diamati di dekat hati (100,51%). Kisaran nilai penyusutan longitudinal, radial, dan tangensial adalah 0,39-0,88%; 2,75-3,93%; dan 4,30-6,68%, secara berturutan. Hasil analisis keragaman menunjukkan pengaruh faktor tempat tumbuh dimana sampel Nglipar memberikan nilai penyusutan longitudinal dan tangensial terendah. Nilai penyusutan total dalam kisaran 5,26-15,07%, sedangkan perbandingan penyusutan tangensial dan radial (rasio T/R) antara 1,38-2,13. Secara umum, kerapatan dasar yang diukur mempunyai nilai yang tidak jauh dengan nilai dari beberapa penelitian terhadap jati konvensional serta lebih tinggi dari beberapa jati unggul dari kultur jaringan pohon umur muda. Perlu diperhatikan adalah tingginya penyusutan dan ketidakstabilan dimensi yang diukur di beberapa sampel dalam eksperimen ini.Kata kunci: Tectona grandis, sifat fisika, kerapatan dasar, hutan rakyat, GunungkidulA study of teak wood quality from community forests in Gunungkidul III. Physical propertiesAbstractThe objective of this work is to explore the variation of physical properties of wood from teak trees grown in 3 different sites (Panggang, Playen, Nglipar) from community forests of Gunungkidul Regency. The measured parameters were green moisture content (GMC), basic density (BD), and linear as well as volumetric shrinkage. The three trees were collected at each site then were divided into three axial parts i.e. base, center, and top of the trees. Further, each axial part was divided into 3 radial positions i.e. near pith, middle, and near bark. The range of BD and GMC values were 504-672 kg/cm3 and 47-125%, consecutively. The result of analysis of variance showed that samples of Playen at the top parts tended to give higher average values of all physical properties measured as well as the samples at near bark of radial position. Samples from Nglipar exhibited the lowest range of GMC values (47-70%) whereas the highest values in the radial direction were observed in the near pith samples (100.51%). The range values of longitudinal, radial and tangential shrinkage were 0.39-0.88%; 2.75-3.93%; and 4.30-6.68%, respectively. By analysis of variance, site factor significantly affected of which samples of Nglipar showed the lowest levels of longitudinal and tangential shrinkage. The total shrinkage values were 5.26-15.07% as the T/R ratio were 1.38-2.13. In general, the BD levels of teak from Gunungkidul were comparable to those reported for conventional for teaks plantation and higher than those of young tissues cultural teaks. However, attention should be taken as the high magnitude of shrinkage as well as dimensional stability showed by several samples in this experiment. 
STUDI MUTU KAYU JATI DI HUTAN RAKYAT GUNUNGKIDUL. V. SIFAT KIMIA KAYU Lukmandaru, Ganis; Mohammad, Arsyi Rahman; Wargono, Pito; Prasetyo, Vendy Eko
Jurnal Ilmu Kehutanan Vol 10, No 2 (2016)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (301.907 KB) | DOI: 10.22146/jik.16511

Abstract

Penelitian ini bertujuan untuk mengeksplorasi sifat kimia kayu jati dari hutan rakyat Kabupaten Gunungkidul. Pohon (dbh 28-37 cm) diambil dari tempat tumbuh berbeda yaitu Nglipar, Panggang, dan Playen. Setiap tempat diambil 3 pohon sebagai ulangan dan sampel yang digunakan adalah disk yang diambil dari bagian pangkal. Penampang radial disk dibagi menjadi 3 bagian, yaitu gubal, teras luar, dan teras dalam. Sifat kimia yang diuji adalah kadar holoselulosa, á-selulosa, hemiselulosa, lignin, ekstraktif etanol-toluena, kelarutan dalam air panas, kelarutan dalam NaOH 1%, dan abu. Sebagai pembanding, digunakan kayu jati dewasa dari tegakan Randublatung (Perhutani). Kisaran nilai kimia dari komponen dinding sel kayu jati Gunungkidul adalah kadar holoselulosa 75,76-79,74%, á-selulosa 46,72-50,90%, hemiselulosa 27,41-30,14%, lignin 29,22-32,80%, dan kelarutan dalam NaOH 1% sebesar 16,43-17,35%. Selanjutnya, kadar ekstraktif etanol-toluena, kelarutan dalam air panas, dan abu adalah 5,04-10,77%, 2,74-7,85%, dan 0,60-1,66%, secara berurutan. Interaksi antara kedua faktor berpengaruh nyata pada kadar holoselulosa, á-selulosa, hemiselulosa, dan ekstraktif etanol-toluena. Faktor tempat tumbuh berpengaruh nyata pada kadar abu sedangkan faktor radial berpengaruh nyata pada kadar kelarutan dalam air panas dan abu. Kayu jati dari Gunungkidul memberikan nilai rerata kadar ekstraktif etanol-toluena dan abu yang lebih rendah sedangkan nilai di parameter lainnya masih dalam kisaran nilai kayu jati dari Randublatung.Kata kunci: Tectona grandis, sifat kimia, hutan rakyat, arah radial, Gunungkidul A Study of Teak Wood Quality from Community Forests in Gunungkidul. V.Wood Chemical PropertiesAbstractThis study aimed to explore the chemical properties of teak wood grown in community forests from Gunungkidul Regency. Trees (dbh 28-37 cm) were selected from three different sites i.e. Nglipar, Panggang, and Playen. Three trees were cut from each site and disks were taken from the base of the trees. The disk in radial cross section was divided into 3 parts: sapwood, outer heartwood, and inner heartwood. Chemical properties tested were holocellulose, á-cellulose, hemicellulose, lignin, ethanol-toluene extractives, hot-water soluble extractives, solubility in NaOH 1%, and ash contents. Mature teakwoods from Randublatung (Perhutani plantation) were used for comparison purpose.The values range of chemical composition in the cell wall components of the Gunungkidul teak wood were holocellulose content 75.76-79.74%, , á-cellulose content 46.72-50.90%, hemicellulose content 27.41-30.14%, lignin content 29.22-32.80%, and solubility in NaOH 1% 16.43-17.35%. Further, the ethanol-toluene extractive, hot-water soluble, and ash content values ranged from 5.04 to 10.77%, 2.74-7.85%, and 0.60-1.66%, consecutively. Interaction between two factors affects significantly to holocellulose, á-cellulose, hemicellulose, and ethanol-toluene extractive contents. The growth-site significantly influence on the ash contents as radial factor has significantly affect on the levels of hot water soluble extractives and ash content. The amounts of ethanol-toluene extractive and ash contents of Gunungkidul teak wood showed the lower values than those of teak from Randublatung. The values of other parameters were remain in the range of value of teak from Randublatung. 
KILAS BALIK SEPULUH TAHUN JURNAL ILMU KEHUTANAN Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 10, No 2 (2016)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (158.041 KB)

Abstract

Kilas Balik Sepuluh Tahun Jurnal Ilmu Kehutanan
STUDI MUTU KAYU JATI DI HUTAN RAKYAT GUNUNGKIDUL. VI. KADAR ZAT ANORGANIK DAN KEASAMAN Lukmandaru, Ganis; Hidayah, Rudy Nur
Jurnal Ilmu Kehutanan Vol 11, No 1 (2017)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1439.068 KB) | DOI: 10.22146/jik.24901

Abstract

Zat anorganik dan keasaman telah terbukti dalam mempengaruhi sifat-sifat kayu. Paper-paper sebelumnya dalam seri ini telah membahas sifat fisik dan kimia kayu jati dari hutan rakyat. Untuk itu, penelitian ini bertujuan untuk mengeksplorasi kadar zat anorganik dan keasaman kayu jati dari hutan rakyat Gunungkidul di 3 tempat tumbuh dengan zona ekologis berbeda (Panggang, Playen, Nglipar). Parameter yang diteliti adalah nilai pH, kadar abu (ASTM D-1102), kadar silika dan silikat (SNI 14-1031-1989), dan kadar unsur zat anorganik (Ca, Mg, K, Na, Fe, Mn, dan Cu) melalui Atomic Absorption Spectrophotometer. Kisaran kadar abu serta kadar silika dan silikat secara berurutan adalah 0,38-2,62%, dan 0,01-1,17%. Kisaran nilai kadar zat anorganik Ca, K, Mg, Na, dan Fe adalah 408?2919 ppm; 69-23705 ppm; 947-1653 ppm; 4-31 ppm; dan 0-326 ppm, secara berturutan sedangkan Mn dan Cu tidak terdeteksi di semua sampel. Selanjutnya, kisaran nilai pH yang diperoleh sebesar 5,23 ? 6,98. Berdasarkan analisis variansi, kadar abu, silika-silikat, dan Na dipengaruhi oleh faktor tempat tumbuh dan arah radial pohon (gubal, teras luar, dan teras dalam). Kayu dari Playen (zona tengah/Ledok Wonosari) menunjukkan nilai yang cukup tinggi untuk kadar abu dan silika-silikat. Faktor arah radial pohon berpengaruh nyata pada unsur Ca, K, dan Mg melalui uji Kruskal-Wallis. Dari analisis korelasi Pearson, didapatkan hubungan kuat antara kadar abu dengan kadar silika-silkat (r = 0,77-0,88) serta kadar abu-Ca (r=-0,51) dan kadar abu-Mg (r=0,59) di bagian teras. Dalam tingkat unsur, hubungan terkuat diamati pada kadar Ca-Mg (r = -0,46). Perhatian khusus perlu diberikan pada kadar silika-silkat yang relatif tinggi di sampel yang diamati karena pengaruhnya terhadap penumpulan peralatan gergaji.Study of Teakwood Quality from Community Forests in Gunungkidul. VI. Inorganic Material Contents and AcidityAbstractInorganic materials and acidity in the wood has been proved to affect the wood properties. The previous paper in this series reported on the physical and chemical properties of teak wood from community forests. Therefore, this study aimed to explore the content of inorganic materials and acidity of teak wood grown in the 3 sites (Panggang, Playen, Nglipar) with different ecological attributes from community forests in Gunungkidul. The evaluated parameters were pH values, the contents of ash (ASTM D-1102), silica and silicates (SNI 14-1031-1989), and inorganic matters (Ca, Mg, K, Na, Fe, Mn, and Cu) by means of Atomic Absorption Spectrophotometer. The ranges of ash and silica-silicates content were 0.38-2.62%, and 0.01-1.17%, respectively. The ranges of inorganic element content for Ca, K, Mg, Na, and Fe were 408?2919 ppm; 69 ? 23705 ppm; 947?1653 ppm; 4 ? 31 ppm; and 0 ? 326 ppm, respectively whereas Mn and Cu were not detected in any samples. Further, the obtained pH values range was 5.23?6.98. On the basis of analysis of variance, the contents of ash, silica-silicates, and Na were affected significantly by site and radial direction (sapwood, outer heartwood, and inner heartwood) factors. The woods from Playen (middle zone/Ledok Wonosari) had significantly high in ash and silica-silicate contents. By Kruskal-Wallis test, radial direction factor affected significantly the levels of Ca, K, and Mg. As defined by Pearson?s correlation analysis, it was found a strong correlation between the ash and silica-silicates contents (r=0.77-0.88), as well as between the ash-Ca content (r=-0.51) and the ash-Mg content (r=0.59) in the heartwood part. In the inorganic element levels, the strongest correlation was measured between Ca-Mg content (r=-0.46). Special attention should be given to the comparatively high amounts of the silica-silicates content in the observed samples as it would dull cutting tools considerably.
VARIABILITY IN THE NATURAL TERMITE RESISTANCE OF PLANTATION TEAK WOOD AND ITS RELATIONS WITH WOOD EXTRACTIVE CONTENT AND COLOR PROPERTIES Lukmandaru, Ganis
Indonesian Journal of Forestry Research Vol 8, No 1 (2011): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Property of natural termite resistance of teak (Tectona grandis)wood signifies one of its most important characteristics. With the purpose of understanding the variation in such resistance, four teak trees in the form of trunk (stem) from Randublatung , Central Java were randomly selected, and each wood portion sampled in radial and axial direction. Extractive content and color properties of the teak wood were also measured and correlated with properties of its natural termite resistance. Bioassay test was conducted by no-choice feeding method using Reticulitermes speratus Kolbe termites. The extractive contents were determined by successive extraction using n-hexane, ethyl acetate, and methanol, respectively. Color properties were measured with the CIELAB system. Results showed that antitermitic activity of the teak wood was affected by radial and axial position in the corresponding tree. The wood from middle part of the trees in axial direction exhibited the most resistant to termites (mean mass loss = 1- 4 mg ), while in radial direction the sapwood exhibited the least resistance ( greatest mass loss), and moving inward to the near-pith heartwood the resistance tended to decrease somewhat (slight increase of mass loss). Heartwood and sapwood part differed significantly in ethyl acetate and methanol- soluble extractive contents. Apparently, the greater the ethyl-acetate-soluble extractives (EEC) then the higher the termite resistant (lower mass loss), and conversely the greater the methanol- soluble extractive (MEC) then the lower the termite resistant ( greater mass loss). The brightness index (L*) and redness index (a*) varied significantly in radial direction, however, no significant variation was found in color properties within the heartwood. No strong degree correlation was measured between the mass loss due to termite activity and extractive content parameters. In both heartwood and sapwood, a significant negative correlation (r = -0.50) was found between the mass loss and redness (a*), while correspondingly a significant positive correlation (r = +0.54) occurred between brightness and mass loss. These occurring phenomena strongly suggested that the red colored teak wood was brought about by the moderately polar EEC (e.g. tannin, quinone, and other polyphenol) that inflicted teak-wood resistance against termite (lower mass loss), while the bright-colored teak wood was due to the highly polar MEC (e.g sugar and other soluble carbohydrate) which were conversely responsible for lowering termite resistance ( greater mass loss).
KOMPONEN KIMIA KAYU JATI DENGAN PERTUMBUHAN EKSENTRIS Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 5, No 1 (2011)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (10926.045 KB) | DOI: 10.22146/jik.579

Abstract

Tujuan penelitian ini adalah untuk mengetahui kualitas kayu cacat. Spesimen penelitian berupa 10 pohon miring yang diperoleh dari kegiatan penjarangan dari tegakan jati (Tectona grandis L.f.) di Randublatung, Jawa Tengah. Pada setiap pohon, kayu di bagian eksentrisnya dipisahkan \, kemudian sampel serbuk kayu diambil pada bagian teras terluar pada kedua lebar lingkaran tahun maksimum (bagian atas pohon miring) dan pada arah yang berlawanan, yaitu yang mempunyai lebar lingkaran tahun minimum (bagian bawah pohon miring). Serbuk kayu dihaluskan sampai mencapai 40-60 mesh untuk analisis kimia. Analisis data melalui uji t pohon pada kadar ekstraktif etanol-benzena (4-12%), kadar terlarut air panas (1-3%), kadar abu (0,7-3%) dan kadar lignin terlarut asam (0,7-1,4%). Pengukuran menggunakan GC dan GC-MS, menunjukkan tidak ada beda yang mencolok pada jumlah komponen utama ekstraktif etanol-benzena. Sebaliknya, kayu dengan lingkaran tahun paling lebar secara konsisten memiliki kadar lignin Klason lebih tinggi (32-35%) dibandingkan kayu dengan lingkaran tahun sempit (29-33%). Hasil-hasil tersebut menunjukkan bahwa eksentris lebih berkaitan dengan komponen dinding sel kayu daripada zat-zat metabolism sekunder. Selanjutnya, tidak terlihat juga adanya indikasi terhadap pembentukan kayu tarik.Kata kunci: Tectona Grandis, kayu eksentris, pohon miring, sifat kimia, riap tumbuh. Chemical Components of Teak Wood with Eccentric Growth AbstractThe objective of this study is to learn the quality of abnormal woods. The specimens were 10 leaning trees obtained from thinned teak (Tectona grandis L.f.) stand in Randublatung, Central Java. In each tree, the eccentric growth parts were isolated, then wood meal sample was drilled at the outer heartwood part of both maximum annual-ring width (upper part of leaning stem) and in its opposite side, which had minimum annual-ring width (lower part of leaning stem). The wood meals were ground to size of 40-60 mesh for chemical analysis. Data analysis by paired t-test showed that no significant difference was found between the upper and lower parts in ethanol-benzene extractive content (4-12%), hot-water soluble content (1-3%), ash content (0.73%) and acid soluble lignin content (0.7-1.4 %) . By means of Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS), no striking difference was also observed in the levels of major components of ethanol-benzene extracts. On the other hand, in Klason lignin content, the wood with widest ring consistently showed a higher content (32-35 %) than that with narrowest ring (29-33 %). These findings indicated that the eccentricity is more related to cell wall components than to secondary metabolites. Further, there is no indication with regard to the formation of tension wood.
Chemical properties of modified mahogany wood by heat treatment Lukmandaru, Ganis; Susanti, Dewi; Widyorini, Ragil
Jurnal Penelitian Kehutanan Wallacea Vol 7, No 1 (2018): Jurnal Penelitian Kehutanan Wallacea
Publisher : Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (194.727 KB) | DOI: 10.18330/jwallacea.2018.vol7iss1pp37-46

Abstract

Mahogany woods from community forests generally have relatively low qualities due to lack of maintenance activities and for their young harvesting stage. Heat treatment is known as wood modification method that could improve the quality of the wood. The aim of this study was to determine the interaction effect of temperature and method of heat treatment on the chemical properties of young mahogany wood. Materials used in this research were mahogany wood boards from community forest which were heat-treated using oven and steam methods performed at the temperature of 90°C, 120°C, and 150oC for 2 hours. In this research, some chemical changes were analyzed. Results of the research showed that the interaction of temperature and heat treatment method gave a significant decreasing on the pentosan amount, and hot-water extractive solubility, particularly the steaming at 150oC. The increasing temperature of heat treatment significantly decreased the content of holocellulose, α-cellulose, hemicellulose, and pH values whereas it increased lignin content,  extractives (cold-water and alcohol-benzene extractives) and solubility in 1% NaOH. Steaming method provided lower levels in the content of holocellulose, ethanol-benzene extract, cold-water solubility, and pH values compared to the oven heating. However, the steaming method over 1200C should be considered as it would reduce the wood strengths.