Analisis Transformasi Penampang Kayu Laminasi Kelapa Sawit Menggunakan Model Distribusi Ikatan Pembuluh

Abstract

Palm oil (Elaeis guineensis Jacq.) is one types of plants belonged to monocot plants. In general, the anatomical structure of the trunk is composed of vascular bundles and parenchyma as essentially network. Basically, both of these components affect the characteristics of the wood. Based on the function, vascular bundles serve as the supporting structure and the transport system, while the parenchyma is the food storage elements. In a cross-sectional trunk, uneven pattern of vascular bundles is generated which continuously decreases from the outer to the center of the stem so that it will directly affect the characteristics of the "wood". The purpose of this research are to find a mathematical model of the relationship between the distribution of vascular bundles with a characteristic "wood" oil palm trunks and use this model in the transformed cross section of laminated wood oil palm trunk. This study consists of four stages. The first stage of observation influences the distribution of vascular bundles in the direction of the horizontal/radial (outer to the center of the stem) and vertical/longitudinal (base to top) of oil palm trunks on the characteristics of the "wood" (density and mechanical properties). The second phase is laminated wood characteristics of oil palm trunk. The variables used in this phase is the height position "wood" on the oil palm trunk (2 m, 4 m, 6 m), glue rate (200 g m-2, 250 g m-2, 300 g m-2) and press time (1 hour, 2 hours, 3 hours). The third stage is the influence of the thickness of the oil palm lamina taken from the outer of the trunk of the characteristics of wood laminations. Lamina raw material used was taken from a height of 2 m, 4 m and 6 m with a thickness of 6 cm, 3 cm, 2 cm, and 1.5 cm. The glue rate of adhesive and press time used in this phase refers to the second stage. Dimensional cross-section is made of laminated wood 6 cm by 6 cm. This phase of research aims to analyze the influence of the thickness of the lamina of the laminate wood characteristics of oil palm trunk. The last stage of the research is to analyze the modulus of elasticity laminate of oil palm trunk with methods Transformed Cross Section (TCS) based on the distribution of vascular bundles obtained from the first and the third stage. The results showed that the distribution of vascular bundles can be assumed as a function of distance from the edge to the center of the stem and is expressed in non-linear regression equation (power). The characteristics of oil palm wood are influenced by the distribution of vascular bundles. In the horizontal direction, the greater the number of vascular bundles distribution, density and mechanical properties will be higher, while the vertical direction indicates the opposite phenomenon. This relationship can be modeled in a multiple linear regression equation are : y = 0.221 - 0.023x1 + 0.001x2; R2 = 82% (density), y = 11609 - 2517x1 + 132x2; R2 = 70% (MOE), y = 76.710 - 13.942x1 + 0.852x2; R2 = 71% (MOR), y = 42.944 - 7.577x1 + 0.422x2; R2 = 69% (compressive parallel to grain), y = 50.950 - 8.413x1 + 0.523x2; R2 = 77% (hardness), y = 11.189 - 2.413x1 + 0.183x2; R2 = 83% (shear strength) where y is the characteristic of "wood" palm oil, x1 is the origin of the stem height of the sample, x2 is the distribution of vascular bundles. The wettability properties of oil palm wood with isocyanate adhesive shows the resulting contact angle below 90 ° and indicates that the adhesive is fit for use as an adhesive laminate of oil palm trunk. Testing characteristics of laminate 2 layer (shear strength adhesive, wood failure and delamination ratio) obtained the best results with glue rate of 300 g m-2, while the press time required for 1 hour. Characteristics of glulam of OPT influenced by the properties of the laminae. The thinner the laminae taken from the outer part of OPT, the more distribution of the vascular bundles. This causes the density and stiffness of the laminae to also get bigger. At different heights opposite phenomenon occurred as in the earlier study. This relationship is shown by the linear regression equation yMOE = 177864xkerapatan - 32225 (R2 = 82%) and yMOE = 1.0466xMOE lamina + 1748.5 (R2 = 95%). The density of oil palm wood laminated 1.03 to 1.35 times of the density of a solid beam. MOE of oil palm wood laminated 1.54 - 1.66 times of MOE solid beams, while it’s MOR for 1.22 to 1.46 times of MOR beam shear strength of solid and shear strength of oil palm wood laminated 0.86 – 1.43 times of shear strength of solid beams. Based on this, oil palm “wood” laminate produced from thin laminae taken from the bottom of the stem will have higher properties. Value of wood bending (MOE) is closely related to the distribution of the vascular bundles. Therefore, the ratio of distribution of vascular bundles can be used as a substitute for the ratio of modulus of elasticity in transformed cross section analysis of oil palm “wood” laminated. The result shows theoretical value of derived model was not different from the empirical value one. This proved by a very high Pearson correlation values at 94%. Based on the results of testing glulam of OPT characteristics testing, apparently not all of them meet the Japanese Agricultural Standard for Glued Laminated Timber Notification No. 1152 (JPIC 2007). Moisture content and the ratio of delamination have met these standards, while the shear strength, MOR and MOE have not.