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
The use of modern devices and human activity today have increased noise problem. The applicaton of acoustic panels in building construction could be as an alternative to overcome this problem. The purpose of this study was to investigate acoustical properties of sound absorption coefficient and sound transmission loss from wood wool or excelsior board. Three fast growing species, sengon (Paraserianthes falcataria), african wood (Maesopsis eminii), and mangium (Acacia mangium) lumbers were processed to obtain wool particles. Two different categories of board density and types of resins were used in this study. Sound absorption coefficient was determined using the impedance tube method, while that for the determination of transmission loss based on the reverberation room method. The results showed that the board density of 0.8 g/cm3 had good sound absorption for low and high frequencies compared with board of 1.0 g/cm3. In the medium frequencies those boards reflected the sound. Wood wool cement bonded board was good in sound absorption for high frequency. In the range low to high frequencies, the boards with isocyanate adhesive were good in transmission loss value compared with cement bonded boards. Meanwhile, the boards with density of 1.0 g/cm3 possessed transmission loss value higher than board of 0.8 g/cm3.
Keywords: acoustic panel, wood wool board, fast growing species, sound absorption, transmission loss
Physical and mechanical properties of jabon wood particleboards were studied. The wood particle from lower, upper parts of trunk and branches of jabon tree were used. The wood wettability was observed at lower, upper part of trunk and branches of 2.5 years old jabon tree from Cihideung Ilir village, Bogor. The quality of particleboard in terms of density, moisture content, thickness swelling, modulus of elasticity, modulus of rupture, internal bond, and screw holding power were tested accordance with JIS 5908:2003. In general partikel bord made of jabon wood from upper, lower of trunk and branches of jabon were as follow: density (0.61 g/cm³, 0.58 g/cm³, 0.65 g/cm³), moisture content (9.9%, 9.7%, 9.3%), thickness swelling (44.8%; 52.3%; 30.6%), modulus of elasticity (9716.1 kg/cm², 7997.4 kg/cm², 12954.3 kg/cm²), modulus of rupture (82.6 kg/cm², 71.3 kg/cm², 90.8 kg/cm²), internal bond (5.06 kg/cm², 3.02 kg/cm², 6.12 kg/cm²) and screw holding power (30.6 kg/cm², 38.8 kg/cm², 47.5 kg/cm²), respectively. The quality of jabon wood were not affected by the precentage of adhesive used. There were a variability in wettability of jabon wood between parts of tree. The wettability of jabon wood of upper, lower trunk and branches were 1800.4, 2126.1 and 2169.7 mm, respectively. Furthermore, the variabilities were also happened in almost all physical dan mechanical properties of the particleboard. The higher the wettability the higher the quality of the particleboard, means that wettability as a good indicator for quality of jabon woods particleboard.The quality of particleboard made of woods from branches were better than others.
Keywords: particleboard, jabon, wettability,gluability
The acidity of wood and panel product was important factor to impact on metal corrosion and give effect on adhesive curing time. The objective of this research was to explore of pH and buffering capacity from nine tropical woods. Method to determination of pH and buffering capacity reffers to Johns and Niazi (1980) experiment. The result of this research showed that nine tropical woods which observed had different acidity and buffering capacity. The range of wood acidity had pH 4-7. The correlation value of pH and buffering capacity from this research about 4-5 for base and acid buffering.
Keywords: acidity of wood, pH, buffering capacity.
The use of wood as a construction material is still the primary choice for most Indonesian people. For the purposes of structural construction, it would require a long span of wood, whereas stock in the market is limited, so usually it is overcomed with joint technique which can be done with type of joint and connector. Kind of joint that is needed to be considered seriously is tensile, shear and moment joint. Nail joint is relatively cheap and easy to be done. Variables which are used to see and predict the level of allowable load for a nail joint are diameter and number of nails. Therefore, the objective of this research was to know the influence from the variables to the strength of joints under uni-axial compression loading from 3 wood species. The results showed that double shear connections strength of nangka wood (allowable load per nail and also total load) has the highest value compared with rasamala and sengon. Nangka wood also reached the highest value for maximum crushing strength. Maximum crushing strength had positive relationship with double shear connections strength. Based on the result of this research, maximum crushing strength is applicable to predict the strength of nails.
Keywords : allowable load, maximum crushing strength, nails, double shear connections, tensile joint
Enhancement of surface appearance of wood products in wood working industry has been done by application of wood stain. However, the use of wood stains has been recently limited due to emission of a hazardous material. Through this work a new technique of ammonia fuming has been experimented. The purpose of the research work was to investigate the effect of ammonia fuming and wood characteristics on the surface appearance of nangka wood (Artocarpus heteropyllus). The experimental result showed that ammonia in the volume of 2 liter could change significantly the natural color of (16 x 8 x 2) cm size nangka wood after 24 hours of fuming. Increasing in the period of fuming to 48 hours did not provide any difference in color compared to the 24 hours of fuming, however the 48 hours fuming generated deeper changes in color on the surfaces of the wood. Heartwood of nangka was observed to generate more significant changes in color compared to the sapwood. Fresh wood produced a darker color than air-dried wood. The wood treated by ammonia fuming showed an increase in resistance against termite and decayed fungi attacks.
Keywords : ammonia fuming, finishing, heartwood and sapwood, preservation
