Studi Pengaruh Kondisi Penyetelan Nosebar Pada Mesin Kupas Terhadap Tekanan Kempa Dan Kualitas Potong Venir Study on the Influences of Nosebar Setting of a Peeler on the Compressive Forces and Cutting Quality of Veneer

For good cutting quality all peeling machines are always equipped with a nosebar. Position of the nosebar over the knife –determined by the gap and lead– is adjusted until it forms the knife-nosebar's opening slightly smaller than the depth of cut. As the result, the compressive forces, which are important for controlling veneers' depth of lathe checks, thickness deviation and surface roughness are imposed on the wood. In cutting forces analysis of many veneer-cutting studies, researchers are only able to analyze the characteristic of forces act at the knife, but the characteristic of forces at the nosebar and the compressive forces on wood has never been revealed. In this study the characteristic of the forces acting at the knife (Xc, Yc) and the nosebar (Xb, Yb), as well as the compressive force imposed on the wood are studied and discussed. It is also discussed the tripartite relationships between the nosebar setting, the compressive force, and cutting quality

Treatment of Oil Palm Wood with Low-Molecular Weight Phenol Formaldehyde Resin and Its Planing Characteristics

In line with the Malaysian government calls to turn waste into wealth, oil palm wood (OPW) is establishing itself as a potential wood substitute. However, the OPW on its own has four imperfections, i.e.: low strength, low durability, poor dimensional stability, and poor machining characteristics. Previous studies have shown that the first three imperfections were able to be solved by impregnating with low molecular weight phenol formaldehyde (Lmw-PF) through modified compreg method. But, the machining behaviour of OPW remains uncovered. A planing test was carried out to evaluate the machining characteristics of the treated OPW. For comparison purpose, another set of test for the rubberwood and untreated OPW samples were also conducted. It is acknowledged that the planing quality of the treated OPW is of equal grade to that of rubberwood. In general, the planing of the treated OPW and the rubberwood fell into the Grade I (very good), compared to Grade III (average) for untreated OPW. The treatment significantly improves the machining characteristics of OPW, adding significant improvements on the physico-mechanical properties, durability, and appearance that have been proven in the previous studies, which make it can be used as a new, high-grade alternative for solid wood material

Reduction of Formaldehyde Emission From Phenol Formaldehyde Treated Oil Palm Wood Through Improvement of Resin Curing State

Oil palm wood (OPW) has several imperfections, and impregnation with low molecular- weight phenol formaldehyde resin through a modified compreg method can practically enhance these properties. The treated OPW, however, releases a considerable amount of free formaldehyde and thus is unhealthy for the human being. To make it applicable for indoor material, formaldehyde emission (FE) should be lowered to 0.1 ppm or lower. The FE level of the treated OPW was reduced from 0.3 to 0.1 ppm or lower by improving the resin curing state through two approaches, i.e. modifying the hot pressing compression schedule during the process and adopting an extended drying after the process. It is acknowledged that the extended drying gave more effect on the FE reduction than that of modifying hot-pressing schedule. The combination pressing schedule of 12.5%®25%®50% and extended drying of 48 h emits the lowest, safe formaldehyde of 0.08-0.10 ppm, which is considered safe according to American National Standard Institute (ANSI) standard. The improving resin curing state through modifying the hot pressing schedule and adopting extended drying could be used as a practical way to reduce the FE level of the treated OPW to a safe level suitable for various furniture and indoor applications

Distribution of Oil Palm Starch for Different Levels and Portions of Oil Palm Trunk

It is widely known that starch can be heated to have adhesive characteristic. The properties of starch rich, low density oil palm wood from the inner part of oil palm trunk (OPT) have been seen to be possible improved through steam-densification process by using in situ starch as binding agent. For that, the distribution and characteristic of the extracted starch at different height and portions of OPT are first need to be investigated. Starch extraction of OPT was made by traditional grating-dissolving method in water. Starch distributions were found more concentrated in core portion and it increased as the heights increasing. At the first 2 m height above the ground, mean extracted starch content was 2.9%, 4.3% and 5.6% for the outer, middle and core respectively. Regardless of portion, mean extracted starch content was 4.3%, 7.4%, 7.7% and 8.5% for the first, second, third, and fourth 2 m trunk height respectively. Regardless of level, mean extracted starch content was 4.9%, 7.2% and 8.8% for the outer, middle and core portion respectively. Other study using Na2S2O5 as solvent gave 7.15% mean starch content for the oil palm slabs (the outer portion). Further study on the extracted starch characterization, it was found that the starch from core portion turned into darker blue color than the outer, and the starch from upper level turned into darker blue color than the lower level when they were subjected to iodine test. The blue color is usually used to indicate the purity of starch, the darker the color, the purer the starch. The results suggest that both the extracted starch content and the starch purity were showing the same trend, increased from outer inside and from bottom upside, in the OPT

Effect of resin content and pressure on the performance properties of rubberwood-kenaf composite board panel

The possibility of manufacturing rubberwood and kenaf (Hibiscus cannabinus L.) stem medium density fibreboard (MDF) panels at different pressure and resin content were investigated. The effect of mechanisms of interacted independent variables (resin content and pressure) on MDF properties was analyzed. The board performance was evaluated by measuring internal bond (IB) strength, modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swell (TS). The test results were statistically analyzed by using response surface method (RSM) to determine the significant independent variables that influenced MDF properties. A mathematical simulation or response surface models were developed to predict the MDF properties (MOR, MOE, IB, WA and TS). The obtained results showed that MDF density and all interactions between the experimental variables were significant factors that influenced the mechanical properties of MDF. At 8 bar and 14 % resin content, the MDF recorded WA of 83.12 % and TS of 20.2 %. It can be inferred that two parameters (resin content and pressure) had positive effect on physical and mechanical properties of MDF. We concluded that resin content show more significant effects on MDF manufacturing as compared to pressure parameters