The effect of microwave treatment on the color changes and wettability of sembilang bamboo (Dendrocalamus giganteus Munro)

Bamboo has the potential to be a substitute for wood, although it is no exception that bamboo has many weaknesses. Bamboo is a plant with fast growth, short recycling times, and the potential to be used as structural and non-structural materials. Sembilang bamboo is a bamboo that has a large diameter and is commonly known as giant bamboo. Poor adhesive dispersion was a problem in previous studies, and the presence of discoloration due to important treatments was known. Heating using a microwave is a step in this research to solve the problems that occur. The research was carried out by measuring bamboo samples of a certain size, then the bamboo was scanned, and the wettability was measured initially and at the end of the test. Bamboo samples were heated in the microwave at a certain temperature of 60–75°C for 0.5–1 minute. The results of the 1 minute and 0.5 minute microwave treatment tests can increase wettability so that the spread becomes longer, with a small K value of 0.391. This is presumably because the contact angle is less than 90°. In addition, the treatment also had a small and moderate effect on the color differences that occurred

Lathe Check Characteristics of Fast Growing Sengon Veneers and Their Effect on LVL Glue-Bond and Bending Strength

Fast growing sengon (Paraserianthes moluccana) is largely rotary-cut to produce veneer for core plywood production. In order to provide better information on veneer production and utilization, in this study the effects of wood juvenility and veneer thickness on lathe checks of rotary-cut sengon veneers were evaluated. Before veneer manufacturing, sengon logs were boiled at 50 oC and 75 oC for 4 and 8 hours respectively. The boiled logs were peeled to produce veneer of 1 mm, 1.5 mm, 2 mm in thickness. Lathe checks of veneers were measured on the loosed side at every 5 mm veneer length under an optical video microscope and their frequency, depth, and length were characterized. Twenty sampling points of 5 mm veneer length were prepared from each segmented ring of 1 cm width from pith to bark. Isocyanate resin adhesive were used to produce laminated veneer lumber (LVL) of 20 mm thick, which consisted of 24-ply of 1 mm veneer thick, 14-ply of 1.5 mm veneer thick, and 11-ply of 2 mm veneer thick, for glue bond and bending strength test. Results showed that wood juvenility and veneer thickness determined the frequency, depth and length of lathe checks for the sengon rotary-cut veneers. In general, the frequency of lathe checks of the veneer increases with increasing veneer thickness, and also increases from pith to bark. Boiling of logs before rotary-cutting could decreases the frequency of lathe check of the veneer. The results indicated that boiling of logs at 50 oC for 8 h and at 75 oC at least 4 h before peeling the logs could minimize the frequency of lathe check in manufacturing rotary cut veneer thickness of 1 mm, 1.5 mm, and 2 mm from juvenile wood of fast growing sengon. The frequency of lathe check affect significantly the glue bond and bending strength, in which the glue bond, Modulus of Elasticity (MOE), and Modulus of Rupture (MOR) decrease as the frequency of lathe checks increases.The authors thank the Directorate for Research and Community Service of the Ministry of National Education for the Republic of Indonesia for the research gran

Modelling the effects of wood cambial age on the effective modulus of elasticity of poplar laminated veneer lumber

Key messageA modelling method is proposed to highlight the effect of cambial age on the effective modulus of elasticity of laminated veneer lumber (LVL) according to bending direction and veneer thickness. This approach is relevant for industrial purposes in order to optimize the performance of LVL products.ContextLVL is used increasingly in structural applications. It is obtained from a peeling process, where product’s properties depend on cambial age, hence depend on radial position in the log.AimsThis study aims to highlight how radial variations of properties and cambial age impact the mechanical behaviour of LVL panels.MethodsAn analytical mechanical model has been designed to predict the modulus of elasticity of samples made from poplar LVL panels. The originality of the model resides in the integration of different data from the literature dealing with the variation in wood properties along the radius of the log. The simulation of the peeling process leads to veneers with different mechanical properties, which are randomly assembled in LVL panels.ResultsThe model shows a correct mechanical behaviour prediction in comparison with experimental results of the literature, in particular with the decrease in MOE in LVL made of juvenile wood. It highlights that the bending direction and veneer thickness have no influence on the average MOE, but affect MOE dispersion.ConclusionThis paper proposed an adequate model to predict mechanical behaviour in the elastic domain of LVL panels based on the properties of raw wood material.ANR xyloforest, région Bourgogne franche-comt

Pengujian Efikasi Skala Laboratorium Kayu Hasil Fumigasi Terhadap Serangan Rayap Tanah (Coptotermes curvignathus)

Fumigated wood was assumed to retain durability level against wood destroying factors. Due to lack of data, fumigated wood durability against wood destroying factors needs to be investigated, especially toward subterranean termites. The aim of this research was to evaluate fumigated wood durability against subterranean termites attack in laboratory scale (ASTM D 3345-2008). Wood samples used were sengon (Falcataria moluccana), rubberwood (Hevea brasiliensis), and mangium (Acacia mangium). Samples of 2.5 × 2.5 × 0.6 cm were fumigated inside 2 × 1 × 1 m of fumigation chamber using 2, 4, 6, 8, and 10 liters of ammonia solution for 4 days. The samples were then transferred into glass bottle, along with sterile sand and 200 worker and 20 soldier subterranean termites. After 4 weeks, mortality and weight loss percentage were measured. All treatments showed 100% of mortality, while a significant decline in weight loss percentage was varied depends on wood species as well as the volume of ammonia. Therefore, fumigated wood was proven resistant against the attacks of subterranean termites

Correlation between Radial Variation and Mechanical Properties of Laminated Veneer Lumber made from 14 Poplar Cultivars

France is poplar largest producer in Europe. Most of companies have a very specialized raw material supply chain since they use almost one type of cultivar for their specific products. For example, I-214 is very suitable for light packaging, consider as exclusive raw material in all industries. However, to prevent companies from a potential disease of their unique raw material, we need to find alternative cultivars. 14 cultivars were then characterized in terms of material, mechanic, peeling, wood pulp properties in a collaborative project (CNPF-IDF, FCBA, INRA, ENSAM). As common knowledge, juvenile wood had lower mechanical properties than mature wood. In this research, we gave information about mechanical properties of LVL made from juvenile and supposed mature veneers from 14 poplar cultivars. Its objective was to classified veneer poplar cultivars into two categories: suitable for structural purposes and non-structural purposes. From each cultivars (theirs ages were 13-19 years old), we took two logs, then we peeled into 3 and 5.2 mm thick veneers. We separated veneers that resulted from sapwood and heartwood to produce LVL panels mostly performed with juvenile wood or “more mature” wood. The veneers were glued using polyvinylacetate (PVAC). The boards were then cut into standardized samples (21*21*500 mm) for mechanical tests, i.e. four points bending tests (1280 samples). Before these tests, nondestructive measurements of the MOE have been made on the bending samples using the BING method (vibration tests). The results showed that correlation between destructive and non-destructive test was 0.79 (it means nondestructive test could be used as reference to estimate MOE). Based on non-destructive test, poplar cultivars which were categorized for potential structural purposes, were: Brenta, Lambro, Soligo and Taro. The rest of poplar cultivars (A4A, Alcinde, Dvina, I-214, Koster, Lena, Mella, Polargo, Trichobel and Triplo) were categorized in non-structural. Also we found, there was a significant effect of juvenility for each cultivar . Sample taken from each veneer constituting panels were taken to measure the Micro Fibril Angle. The next step is to analyze the effect of MFA on mechanical characteristics of the panels for different cultivarsThe research was carried out with the use of equipment funded by the French National Agency for Research under the program "Investments for the Future" (ANR-10-EQPX-16

Uji Performa Alat Vakum Tekan Termodifikasi Untuk Impregnasi Kayu

The impregnation process is carried out to increase the resistance of wood from the attack of microorganisms such as fungi and termite attacks by placing the wood in a vacuum tube and then placing an impregnan solution into it. The limited ability of impregnation tubes is an obstacle in carrying out research and practicum activities, therefore there needs to be modifications to the impregnation tube so that the impregnation process can provide better results. Verification of the results of impregnation is done by calculating the value of weight percent gain (WPG) and relative standard deviation (%RSD) for the test of the level of appreciation. Based on the results of the experiment the highest %WPG value in the water impregnan solution was obtained from the parameter conditions of the type 3 press vacuum tool, which is with a time of 1 hour and a pressure of 5 bars and is worth (178.29±10.97). The highest %WPG value in boron solution of 5% is obtained from the condition of the type 6 press vacuum tool with a time of 3 hours and a pressure of 5 bars and is worth (5.16±0.45). The smallest %RSD value of water impregnan solution is achieved under the parameter conditions of type 4 tools at 3 hours and pressure 1 bar and is worth 3.99%. The smallest %RSD value of boron impregnan solution is 5% achieved under the parameter conditions of type 2 tools, namely within 1 hour and pressure of 3 bars and is worth 5.36%.The impregnation process is carried out to increase the resistance of wood from the attack of microorganisms such as fungi and termite attacks by placing the wood in a vacuum tube and then placing an impregnan solution into it. The limited ability of the impregnation tube is an obstacle in carrying out research and practicum activities, therefore it is necessary to modify the impregnation tube so that the impregnation process can provide better results with an indication of the increasing amount of impregnant solution that enters the wood in a shorter time. Verification of the results of impregnation is done by calculating the value of weight percent gain (WPG) and relative standard deviation (%RSD) for the test of the level of appreciation. Based on the results of the experiment the highest %WPG value in the water impregnan solution was obtained from the parameter conditions of the type 3 press vacuum tool, which is with a time of 1 hour and a pressure of 5 bars and is worth (178.29±10.97). The highest %WPG value in boron solution of 5% is obtained from the condition of the type 6 press vacuum tool with a time of 3 hours and a pressure of 5 bars and is worth (5.16±0.45). The smallest %RSD value of water impregnan solution is achieved under the parameter conditions of type 4 tools at 3 hours and pressure 1 bar and is worth 3.99%. The smallest %RSD value of boron impregnan solution is 5% achieved under the parameter conditions of type 2 tools, namely within 1 hour and pressure of 3 bars and is worth 5.36%

Pengaruh kondisi fumigasi terhadap efektifitas pewarnaan dan keawetan kayu hutan rakyat

Indonesian log consumption average in 1999-2004 was about 40 million cubic meter per year. Far above the capacity of natural forest to supply wood demand which was only 6.9 million cubic meter per year and only 5 million cubic meter per year from plantation forest. Now community forest has been managed well based on commercial orientation to fullfill the needs of forest products.  Recently community forest is known as realible wood producer for furniture such as rubber wood (Hevea brasiliensis), Maesopsis (Maesopsis eminii), Jeunjing (Paraserianthes falcataria), Durian (Durio spp.), Jackfriut (Arthocarpus sp). However those woods have low appearance quality (pale colours and ununiform, texture not attractive). Thus they need some treatments to enhance their appearance, one of them by fumigation. The purpose of this researh are to gain optimalize fumigation condition (combination between amonia volume and time of fumigation) to have wood stain that resistance from weathering and to analyze durability of fumigation wood against Cryptotermes sp attack.  The treatments were fumigation by 2, 4, 6 litre of amonia for 1, 2, 3 days.  Those treatments were applied on 5 wood species (mahagony, jackfruit, rambutan, menteng and mindi). The results of this research showed that fumigation treatments have effects only on jackfruit, mahagony, rambutan. They did not have effects on menteng and mindi. Because the difference of tanin content between woods, made every wood had different reaction to fumigation (amonia). Based on comparison of all treatments quantitatively showed the most darkened colour of jackfruit was resulted by fumigation by 4 litre amonia for 3 days, mahagony was fumigation by 6 litre amonia for 2 days and rambutan was fumigation by 4 liter amonia for 2 days.  Weathering resistance resulted all wood species did not resist to weathering or their colour fade away. Wood fumigation durability showed 100 % mortality of Cryptotermes sp (on jackfruit, mahagony and menteng), on the other hand mindi showed 83 % and rambutan 89% mortality of  Cryptotermes sp

Pengaruh kondisi fumigasi terhadap efektifitas pewarnaan dan keawetan kayu hutan rakyat

Indonesian log consumption average in 1999-2004 was about 40 million cubic meter per year. Far above the capacity of natural forest to supply wood demand which was only 6.9 million cubic meter per year and only 5 million cubic meter per year from plantation forest. Now community forest has been managed well based on commercial orientation to fullfill the needs of forest products.  Recently community forest is known as realible wood producer for furniture such as rubber wood (Hevea brasiliensis), Maesopsis (Maesopsis eminii), Jeunjing (Paraserianthes falcataria), Durian (Durio spp.), Jackfriut (Arthocarpus sp). However those woods have low appearance quality (pale colours and ununiform, texture not attractive). Thus they need some treatments to enhance their appearance, one of them by fumigation. The purpose of this researh are to gain optimalize fumigation condition (combination between amonia volume and time of fumigation) to have wood stain that resistance from weathering and to analyze durability of fumigation wood against Cryptotermes sp attack.  The treatments were fumigation by 2, 4, 6 litre of amonia for 1, 2, 3 days.  Those treatments were applied on 5 wood species (mahagony, jackfruit, rambutan, menteng and mindi). The results of this research showed that fumigation treatments have effects only on jackfruit, mahagony, rambutan. They did not have effects on menteng and mindi. Because the difference of tanin content between woods, made every wood had different reaction to fumigation (amonia). Based on comparison of all treatments quantitatively showed the most darkened colour of jackfruit was resulted by fumigation by 4 litre amonia for 3 days, mahagony was fumigation by 6 litre amonia for 2 days and rambutan was fumigation by 4 liter amonia for 2 days.  Weathering resistance resulted all wood species did not resist to weathering or their colour fade away. Wood fumigation durability showed 100 % mortality of Cryptotermes sp (on jackfruit, mahagony and menteng), on the other hand mindi showed 83 % and rambutan 89% mortality of  Cryptotermes sp

Pengujian Efikasi Skala Laboratorium Kayu Hasil Fumigasi Terhadap Serangan Rayap Tanah (Coptotermes curvignathus)

Fumigated wood was assumed to retain durability level against wood destroying factors. Due to lack of data, fumigated wood durability against wood destroying factors needs to be investigated, especially toward subterranean termites. The aim of this research was to evaluate fumigated wood durability against subterranean termites attack in laboratory scale (ASTM D 3345-2008). Wood samples used were sengon (Falcataria moluccana), rubberwood (Hevea brasiliensis), and mangium (Acacia mangium). Samples of 2.5 × 2.5 × 0.6 cm were fumigated inside 2 × 1 × 1 m of fumigation chamber using 2, 4, 6, 8, and 10 liters of ammonia solution for 4 days. The samples were then transferred into glass bottle, along with sterile sand and 200 worker and 20 soldier subterranean termites. After 4 weeks, mortality and weight loss percentage were measured. All treatments showed 100% of mortality, while a significant decline in weight loss percentage was varied depends on wood species as well as the volume of ammonia. Therefore, fumigated wood was proven resistant against the attacks of subterranean termites