Glued-laminated (glulam) beams is one of engineered wood products used for structural applications. The objective of this research is to evaluate characteristics of glulam beams made from Acacia mangium Willd. Laminations used were 2, 4, 6, 8 and 12 cm in widthnesses, 2 cm in thickness and 260 cm in length. Each lamination was graded using Machine Stress Grading (namely by Panter or plank sorter) to determine the modulus of elasticity (MOE) value. The glulam beams was 6 cm x 12 cm in five types of cross-section which arranged by various widths and those MOE of laminations. Glulam beams were bonded by water based polymer isocyanate (WBPI) using 280 g/m2 double glue spread. The research results showed that glulam beams made from A. mangium Willd. fulfilled the JAS 234:2003 standard as on following properties: moisture content, MOE, MOR, shear strength and immersion delamination test. However, performance of glulam was unsatisfactory in wood failure ratio and boiling water soak delamination test.
Keywords: Glulam beam, MOE, MOR, shear strength, delamination
Indonesia has various hardwood species which are known for their low permeability, means difficult to be flown by fluid. The fluid absorption into wood is important especially in preservative treatments, in the treatment before slicing wood sampels for wood anatomy and in wetting air dried wood sampels for specific gravity analyses.
The low water absorption of wood are caused by the air presence in cell lumen which could block the water absorption into wood, and anatomy structure of wood itselves. One methode to overcome this problem was vacuum treatment.
The aim of this research was to increase water absorption in cold water soak methode in 6 wood species (Pterocarpus indicus Willd, Nephelium lappaceum L., Artocarpus heterophyllus Lamk., Paraserianthes falcataria L., Shorea spp, Dipterocarpus spp) through vacuum treatment. The size of wood samples were 5 x 5 x 20 cm for cross section orientation, 5 x 5 x 10 cm for radial and tangential orientation with 3 replicants. These wood samples were treated with 5 different treatments : vacuum treatment for 1 hour and cold water soak process for 24 hours (V), vacuum treatment for 2 hours and cold water soak process for 24 hours (VV), vacuum treatment for 3 hours and cold water soak process for 24 hours (VVV), vacuum treatment for 1 hour, cold wtaer soak for 1 hour, and vacuum treatment again for 1 hour and cold water soak process for 24 hours (VRV), dan vacuum and soaking treatment simultaneously for 5 hours and cold water soak process for 24 hours (VRVRV) and as control, without vacuum treatment, just cold water soak process for 24 hours.
The results of this research showed vacuum treatment could increase water absorption. The highest value of moisture content was obtained at cross section direction in all wood species, followed by tangential and radial direction. However, every wood species showed different reactions to these five different treatments.
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Subterranean termite, Macrotermes, play important role on plant nutritive cycles through disintegration and decomposition of organic matter processes. In the other hand, subterranean termite can cause wooden damage in the nature and human dormitory as well. Therefore, Macrotermes are potential pest and need to be controlled. Effective pest-control of subterranean termite can be made when their species status and distribution are well known. This research is aimed to identify the status of species and the dispersal of Macrotermes at their natural habitat in order to explore natural bio-resources richness and as an effort towards effective pest-control due to increasing risk of attack. Survey method was used termite samples were collected at four different locations which are defined by global positioning system (GPS). Nest classification is according to Meyer et al. (2003). The nest mapping is based on the elevations of their natural habitat in Gunung Halimun Salak National Park (900-1000 asl), and (600-700 asl), Yanlappa sanctuary (200-300 asl), and Ujung Kulon Nasional Park (0-100 asl). Phylogenetic relationships analysis showed that subterranean termite Macrotermes in the natural forest community are belongs to one big group Macrotermes gilvus Hagen. Based on nest size, the colony of Macrotermes can be classified into three different sizes: large, medium, and small nest. Large and medium nest can be found in large amount in Yanlappa sanctuary (15 and 23 colonies, respectively) and the majority of small nest occurred in Gunung Halimun Salak National Park at 900 asl (78 colonies). Temperature and humidity is the most environmental factor that can influence on termite and other factor is rain fall, soil structure, and plant vegetation.
Keywords: Distribution, identify, Macrotermes gilvus Hagen, nest
The qualities of core kenaf particle boards were studied. The boards were made of core kenaf particles and their liquids fortified by melamine formaldehyde.
Core kenaf liquids were prepared using 20 – 60 mesh particles, phenol : formaldehyde ratio of 0,5, based on Masri (2005). SNI 06-4567-1998 and JIS A 5908-2003 were used to grade the kenaf liquids and particle board. Factorial analysis 3 x 3 in Complete Randomized Design was applied with 2 replications. Glue spread with 3 levels (10, 15 and 20% of the oven dry weight kenaf particles) and fortification MF with 3 levels (15, 30 and 45% of the solid content of the kenaf liquids) were used. Kenaf particles were cold soaked prior bonding. The condition of bonding operation in making particle board were : pressure of 20 kgf/cm2 at 160ºC for 12 minutes.
The best result of particle board produced by 20% glue spread and 45% MF fortification with the properties as follows : density of 0,7 g/cm3, moisture content of 6,6%, water absorb ability of 55,6%, thickness swelling of 16,6%, screw holding strength of 641,2 N, internal bond of 0,86 N/mm2, MOE of 2131,9 N/mm2, and MOR of 15,3 N/mm2. Fortifications doesn’t significantly affect the quality of the particle boards.
Keywords: Core-kenaf, kenaf liquids, fortification.
Wood has specific base properties of thermal and combustion. Since being grew normally at marginal soil of mining area, sengon buto, waru and gmelina woods were objectified to investigate thermophisic aspect of their usage as substitution fuel in cement production. Examination based on species, ages and horizontal positions of those woods showed that mean of heating value in oven dry and air dry condition was 4.505 kkal/kg and 4.084 kkal/kg, respectively. Determination of wood substitution to ordinary fuel was acquired by accumulating heating value with prediction value of plantation biomass potency; and enquiry for 850 ha mining area resulted that waru wood will contribute about 5,14% to coal total requisite per year, gmelina and sengon buto will contribute about 5,03% and 4,49%, respectively.
Keywords: Wood, heating value, substitution fuel