Sifat Kayu Lapis yang Dibuat dari Lima Jenis Kayu Asal Riau

The objective of this study was to determine the physical and mechanical properties of plywood made of punak (Tetramerista glabra Miq.), meranti bunga (Shorea teysmanniana Dyer ex Brandis), mempisang (Alphonsea spp.), suntai (Palaqium burckii H.J.L.), and pasak linggo (Aglaia argentea Blume). Liquid urea formaldehyde (UF) was used as an adhesive. Data analysis was carried out using a completely randomized design. Results showed that the moisture content and density of plywood produced in this study were around 10.4-10.95% and 0.65 to 0.93 g/cm3, respectively. The modulus of elasticity (MOE) and modulus of rupture (MOR) of plywood produced were between 63.371-123.548 kg/cm2 and 517-1.052 kg/cm2, respectively. It was also found that the tensile strength and bonding strength of the plywood produced were 461.6-1.095 kg/cm2 and 18.97-31.79 kg/cm2, respectively. It was recorded that moisture content and the bonding strength of the plywood produced met the Indonesian National Standard of Plywood. Among others, plywood produced from pasak linggo showed a superior quality. Referring to statistical analysis, it was confirmed that physical and mechanical properties of plywood were significantly affected by wood species, except moisture content. Keywords: mechanical properties, physical properties, plywood, Riau wood specie

Characteristic of Vertically Glued Laminated Bamboo Beam Made of Andong (Gigantochloa pseudoarundinacea (Steud.) Widjaja) Bamboo Strips

The objective of the study was to determine the effect of various layer compositions on the properties of 3-layer vertically glued laminated bamboo beam (LBB). Bamboo strips for LBB fabrication were prepared from mature culms (± 4 years old) of andong bamboo (Gigantochloa pseudoarundinacea (Steud.) Widjaja) collected from private gardens in West Java. The strips were pre-treated by soaking them in 7% boron solution for four hours. Three-layer LBBs were manufactured with six different layer compositions, including bamboo combination with wood planks of manii (Maesopsis eminii Engl.) or sengon (Falcataria moluccana (Miq.) Barneby & J.W. Grimes) as the core layer. The LBB was manufactured using Water Based Polymer-Isocyanate (WBPI) adhesive. The glue spread and cold pressing time applied were 250 g/m2  and one hour, respectively. Results showed that the average density, moisture content, thickness swelling, and width expansion of LBB were 0.65 g/cm3; 11.1%; 2.09%; and 1.99%, respectively. No delamination occurred in all samples using WBPI adhesive, which indicates high bonding quality. The average bonding strength and percentage bamboo failure (dry test) of  LBB were 61.6 kg/cm2  and 90%, respectively. The physical and mechanical properties of LBB were significantly affected by the layer composition. The presence of wood laminates as the core layer of LBB and the cross wide orientation of the core layer decreased mechanical properties of LBB. On the contrary, the presence of cross-layer in LBB structure increased dimensional stability of the produced LBB.Three-layer thick laminated bamboo beam made of vertically glued andong bamboo strips with various constituted layer  composition and  all constitued layers laminated together in parallel grain direction had strength values comparable to those of class II of solid wood strength, eventhough the core layer was made of sengon or manii planks

KUALITAS HARDBOARD DUA JENIS BAMBU DENGAN TAMBAHAN TANIN RESORSINOL FORMALDEHIDA

Hardboard dapat dibuat dari berbagai macam bahan serat berligno-selulosa. Di Indonesia dewasa ini ketersediaan bahan baku serat konvensional (khususnya kayu hutan alam tropis) untuk hardboard semakin terbatas dan langka, sedangkan produksi domestik hardboard belum dapat memenuhi kebutuhan yang ada. Bahan baku serat alternatif  yang potensinya berlimpah dan belum banyak dimanfaatkan perlu diperkenalkan, diantaranya bambu. Penelitian pemanfaatan bambu sebagai bahan baku pembuatan hardboard telah dilakukan dengan memanfaatkan dua jenis bambu yaitu bambu tali (Gigantochloa apus) dan bambu ampel (Bambusa vulgaris). Masing-masing jenis bambu diolah menjadi pulp dengan proses semi-kimia soda panas terbuka.  Hardboard dibuat dengan 5 proporsi campuran pulp bambu tali + bambu ampel yaitu 100%+0%, 75%+25%, 50%+50%, 25%+75%, dan 0%+100%. Tiap proporsi ditambahkan perekat tanin-esorsinol-formaldehida (TRF) sebesar 0%, 6% and 8% dari berat kering pulp. Lembaran hardboard dibentuk dengan cara basah lalu diuji sifat fisis dan mekanisnya. Hasil penelitian menunjukkan penambahan TRF hingga 8% meningkatkan sifat fisis dan mekanis hardboard. Hardboard dari serat pulp bambu ampel 100% memiliki kualitas tertinggi karena sifatnya banyak memenuhi persyaratan JIS dan ISO untuk kerapatan, modulus elastisitas lentur (MOE), modulus patah (MOR) dan keteguhan rekat internal (IB). Sementara itu, hardboard dari serat bambu tali 100% memiliki kualitas terendah. Performa hardboard dari campuran pulp bambu tali + bambu ampel pada proporsi 50%+50% dan 25%+75% memiliki tingkatan kualitas pada urutan kedua dan ketiga. Papan serat bambu tali yang berkualitas rendah diharapkan dapat diperbaiki melalui penambahan perekat TRF

PENGARUH LAMA PERENDAMAN PARTIKEL, MACAM KATALIS DAN KADAR SEMEN TERHADAP SIFAT PAPAN SEMEN

Penelitian ini bertujuan mengetahui pengaruh lama perendaman partikel, macam katalis dan kadar semen terhadap sifat papan semen. Papan semen skala laboratorium dibuat dengan menggunakan partikel kayu manii (Maesopsis eminii) yang sudah direndam dalam air dingin selama 24 jam dan 48 jam. Perbandingan antara partikel kayu : semen : air dua macam yaitu 1 : 2,4 : 2 (kadar semen 240%) dan 1: 2,5 : 2 (kadar semen 250%). Katalis yang digunakan tiga macam yaitu kalsium klorida (CaCl,), magnesium klorida (MgCl,). dan aluminium sulfat (Al2 (SO4)3) dengan tingkat kadar 5% dari berat semen. Di samping itu dibuat juga papan semen tanpa menggunakan katalis sebagai kontrol atau pembanding. Hasil penelitian menunjukkan bahwa perendaman partikel 48 jam tidak berpengaruh nyata dalam memperbaiki sifat papan semen manii dibanding lama perendaman partikel 24 jam. Sifat papan semen manii sangat dipengaruhi oleh macam katalis yang digunakan. Penggunaan katalis MgCl2 memberikan sifat kestabilan dimensi dan keteguhan lentur yang lebih baik dibanding katalis lainnya. Kadar semen sangat berpengaruh terhadap sifat fisis dan mekanis papan semen manii. Semakin tinggi kadar semen semakin baik sifat fisis dan mekanis papan semen yang dihasilkan. Penggunaan kadar semen semen 250% dapat meningkatkan keteguhan lentur sekitar 31% disbanding kadar semen 240%. Peningkatan kadar semen menyempurnakan stabilitas dimensi sekitar 24-30% pada pengembangan tebal, sekitar 20-40% pada pengembangan linier dan sekitar 10-12% pada penyerapan air

KARAKTERISTIK LAMINASI BAMBU PADA PAPAN JABON

Tanaman jabon (Anthocephallus cadamba Miq.) sudah banyak ditanam oleh masyarakat sebagai bahan alternatif untuk keperluan bangunan dan mebel. Kayu jabon memiliki dua kelemahan, yaitu tidak kuat (termasuk kelas kuat IV) dan tidak awet (kelas awet V). Untuk meningkatkan sifat kekuatan kayu jabon dalam penelitian ini dilakukan pembuatan papan komposit kayu jabon laminasi bambu atau papan jabon laminasi bambu (PJLB). Bambu yang digunakan adalah bambu mayan (Gigantochloa robusta Kurz) dan bambu andong (Gigantochloa pseudoarundinaceae (Steudel) Widjaja). Kayu jabon dan bilah bambu andong dan bambu mayan yang digunakan untuk membuat PJLB direndam dalam larutan boron 7% hingga mencapai target retensi 6 kg/m3. PJLB dibuat dengan empat macam komposisi lapisan, menggunakan perekat isosianat dengan berat labur 250 g/m2 permukaan, dikempa dingin dengan lama pengempaan satu jam. Penelitian ini bertujuan untuk mengetahui peningkatan kualitas kayu jabon akibat rekayasa PJLB dan pengaruh jumlah lapisan bambu tersebut terhadap sifat PJLB. Hasil penelitian menunjukkan bahwa kualitas PJLB secara nyata dipengaruhi oleh jumlah lapisan bambu, kecuali keteguhan rekatnya. Pelapisan bambu pada kayu jabon (PJLB) telah meningkatkan nilai kerapatan sebesar 10%, modulus elastisitas (MOE) 71%, modulus patah (MOR) 34% dan keteguhan tekan 20% dibanding kayu jabon tanpa laminasi. PJLB memiliki sifat mekanis atau kekuatan setara dengan kayu kelas kuat III

Pangsor (Ficus callosa WILLD) and kecapi (Sandoricum kucape MERR) are usually planted in garden and rural forest. The objective of this study was to determine its specific gravity (SG), maximum crushing strength (σc//), longitudinal modulus elasticity (EL), and Poisson’s ratio (n). The compression test was conducted referring to ASTM D143-94(2000) using UTM Instron 3369 which is equipped with two biaxial clip on extensometers. The result showed that vertical and horizontal position of wood in the trees statistically significant influenced on SG and σc//. Horizontal position in Pangsor wood affected its EL, but the other position in both species were not significantly different. There were poor correlations between SG with EL and σc//. Poisson’s ratio value of both woods were in a range 0.0045 – 0.275 for longitudinal-radial direction (nLR), and 0.0151 – 0.1289 for longitudinal-tangensial direction (nLT). Keywords : Longitudinal Modulus of Elasticity, Maximum Crushing Strength, Poisson’s Ratio, Pangsor wood, Kecapi wood

Pangsor (Ficus callosa WILLD) and kecapi (Sandoricum kucape MERR) are usually planted in garden and rural forest. The objective of this study was to determine its specific gravity (SG), maximum crushing strength (σc//), longitudinal modulus elasticity (EL), and Poisson’s ratio (n).  The compression test  was conducted referring to  ASTM D143-94(2000) using UTM Instron 3369 which is equipped with two biaxial clip on extensometers.  The result showed that vertical and horizontal position of wood in the trees statistically significant influenced on SG and σc//.  Horizontal position in Pangsor wood affected its EL, but the other position in both species were not significantly different.  There were poor correlations between SG with EL and σc//.   Poisson’s ratio value of both woods were in a range 0.0045 – 0.275 for longitudinal-radial direction (nLR), and 0.0151 – 0.1289 for longitudinal-tangensial direction (nLT).   Keywords :    Longitudinal Modulus of Elasticity, Maximum Crushing Strength, Poisson’s Ratio, Pangsor wood, Kecapi woo

Color Change and Physical-Mechanical Properties of Polystyrene-Impregnated Glulam from Three Tropical Fast-Growing Wood Species

The aims of this work were to determine the color change and physical–mechanical properties of polystyrene glulam from three tropical wood species. Wood laminas were cut from logs harvested from a young plantation forest of manii (Maesopsis eminii), mangium (Acacia mangium), and rubber-wood (Hevea brasiliensis). The laminas were impregnated with monomer styrene that was polymerized using potassium peroxy-disulfate as a catalyst and heat. Three-layer glulam was constructed from the polystyrene laminas, using isocyanate glue and cold press. For comparison purposes, three-layer untreated glulam and solid wood samples were prepared. The results showed that the color change of polystyrene glulam was very small compared with untreated glulam. Polystyrene glulam had the highest density, while the density of untreated glulam did not differ from that of the solid wood. The moisture content of all products was matched to the environment, and fulfilled the Japanese standard. Compared with both types of glulams, solid wood had lower values for modulus of rupture (MOR), modulus of elasticity (MOE), and hardness, but higher shear strength. Meanwhile, polystyrene glulam had lower values for MOR and MOE, equal shear strength and wood failure, and higher hardness than the untreated glulam. All glulams had very little delamination in the hot water test. Only rubber-wood glulams fulfilled JAS 234-2003 for MOR, MOE, shear strength, and delamination. To obtain adequate physical–mechanical properties of glulams, medium-density wood is recommended for glulam manufacturing

Pangsor (Ficus callosa WILLD) and kecapi (Sandoricum kucape MERR) are usually planted in garden and rural forest. The objective of this study was to determine its specific gravity (SG), maximum crushing strength (σc//), longitudinal modulus elasticity (EL), and Poisson’s ratio (n). The compression test was conducted referring to ASTM D143-94(2000) using UTM Instron 3369 which is equipped with two biaxial clip on extensometers. The result showed that vertical and horizontal position of wood in the trees statistically significant influenced on SG and σc//. Horizontal position in Pangsor wood affected its EL, but the other position in both species were not significantly different. There were poor correlations between SG with EL and σc//. Poisson’s ratio value of both woods were in a range 0.0045 – 0.275 for longitudinal-radial direction (nLR), and 0.0151 – 0.1289 for longitudinal-tangensial direction (nLT). Keywords : Longitudinal Modulus of Elasticity, Maximum Crushing Strength, Poisson’s Ratio, Pangsor wood, Kecapi wood

Pangsor (Ficus callosa WILLD) and kecapi (Sandoricum kucape MERR) are usually planted in garden and rural forest. The objective of this study was to determine its specific gravity (SG), maximum crushing strength (σc//), longitudinal modulus elasticity (EL), and Poisson’s ratio (n).  The compression test  was conducted referring to  ASTM D143-94(2000) using UTM Instron 3369 which is equipped with two biaxial clip on extensometers.  The result showed that vertical and horizontal position of wood in the trees statistically significant influenced on SG and σc//.  Horizontal position in Pangsor wood affected its EL, but the other position in both species were not significantly different.  There were poor correlations between SG with EL and σc//.   Poisson’s ratio value of both woods were in a range 0.0045 – 0.275 for longitudinal-radial direction (nLR), and 0.0151 – 0.1289 for longitudinal-tangensial direction (nLT).   Keywords :    Longitudinal Modulus of Elasticity, Maximum Crushing Strength, Poisson’s Ratio, Pangsor wood, Kecapi woo

Study on Wood in Houses as Carbon Storage to Support Climate Stabilisation: Study in Four Residences around Jakarta Municipal City

Global agreements mandate the international community, including Indonesia, to commit to reducing the risks and impacts of climate change. Indonesia’s Nationally Determined Contributions (NDCs) will contribute to the achievement of the Convention’s goals by reducing greenhouse gas (GHG) emissions and increasing climate resilience. This commitment must be supported by a wide range of actions, including the use of timber. Despite the fact that wood contains carbon, limited information is currently available on the size of the wood utilisation subsector’s contribution to reducing GHG emissions. More research is needed on the magnitude of wood products’ contribution to climate change mitigation. This study assessed the amount of carbon stored in wood used as a building material. Purposive sampling was used to select the cities with rapid housing development surrounding Jakarta’s capital city, i.e., the Bekasi District, East Jakarta City, Depok City, and Bogor District. The amount of carbon stored in wood was calculated according to EN 16449:2014-06 and energy dispersive X-ray spectroscopy (EDS/EDX) analysis. Results show that wood is currently only used in door frames, door leaves, window frames, shutters, and vents. The carbon stored on the components ranges from 450 to 680 kg (average of 554.50 kg) in each housing unit, according to the EN 16449:2014-06 calculation. The weight range is between 130 and 430 kg (average of 400.42 kg) according to EDX/S carbon analysis. With an increase in housing needs of 800,000 units per year, this amount has the potential to store 0.44 million tons of carbon over the lifespan of the products