scholarly journals KUALITAS PAPAN KOMPOSIT YANG TERBUAT DARI LIMBAH KAYU SENGON DAN KARTON DAUR ULANG

PERENNIAL ◽  
2006 ◽  
Vol 2 (1) ◽  
pp. 6 ◽  
Author(s):  
. Suhasman ◽  
Muh. Yusram Massijaya ◽  
Yusuf Sudo Hadi

The use of recycled carton as an alternative material for the layer of composite board may increase the board strength properties. The objective of this research was to find out the influence of face and back layer types on the quality of produced boards. Materials used in this study were wafer made from sengon wood (Paraserianthes falcataria L. Nielsen), water based polymer isocyanate adhesive, and several kinds of cartons such as duplex carton, recycled carton, and waste of corrugated board. The composite board was produced with the target density of 0.65 g/cm3 and the resin solid content of 6% based on oven dry weight of particle, face and back layers. The results are as follows : 1) Utilization of carton layers improved the dimensional stability and bending strength of board; 2) Composite board with recycled carton layer fullfilled the Japanese Industrial Standard (JIS) A-5908-1994 for wafer board type in terms of density, water content, and modulus of rupture (MOR) in lengthwise and widhtwise of board but, did not fullfill that for veneered particled board type; 3) The presence of those layer material types decreased internal bond of the board. Keywords : composite board, face and back layer types, recyled carton

PERENNIAL ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 28
Author(s):  
. Suhasman ◽  
Muh. Yusram Massijaya ◽  
Yusuf Sudo Hadi ◽  
Astuti Arif

This study was aimed to analyze the resistance of composites board made from wafer and carton or paper overlaid on drywood termite and subterranean termite. Materials used in this study were wafer from sengon wood (Paraserianthes falcataria L. Nielsen), water based polymer isocyanate adhesive, veneer, and several kind of carton and paper such as duplex carton, recycle carton, corrugate board, and waste of cement sack. The target density was 0.65 g/cm3, while the resin solid content was 6%. The result of this study showed that no significantly different on infection rate of drywood termite among of composite board types and solid wood. The weight loose of composites board were 1.2–3.8%, while solid wood was 2.7%. Composites board more favorable to infection Macrotermes gilvus than solid wood. The weight loose of composites board were 19.3 – 28.8%, while solid wood was 12.6%. Key words: Composites board, drywood termite, subterranean termite


2019 ◽  
Vol 16 (1) ◽  
pp. 60
Author(s):  
Nur Liyana Aifa Mahammad Asri ◽  
Ainil Idzaty Mohamed Anwar ◽  
Nur Atiqah Najib ◽  
Judith Gisip

Composite panels were manufactured from kenaf particles and treated with two different alkali treatments using 2% NaOH and 2% KOH with resin contents of 8% and 10% of phenol formaldehyde (PF) at medium density of 650kg/m3. The objectives of this study were to determine the mechanical properties in terms of its modulus of rupture (MOR), modulus of elasticity (MOE) and internal bond (IB), and physical properties namely thickness swelling (TS) and water absorption (WA) of treated kenaf board. The mechanical and physical tests were performed according to the Malaysian Standard (MS1787:2004). The minimum requirements value for MOE, MOR and IB were 2000 MPa, 14 MPa and 0.45 MPa respectively for furniture grade particleboards for use in humid conditions (PF2). According to Malaysian specifications for physical properties, the maximum requirement for thickness swell is 15%. Results indicated that both treated boards with NaOH and KOH showed an increase in strength properties compared to untreated particleboard. Particleboard treated with KOH exhibited the highest MOR and MOE values, while board with NaOH treatment gave the highest IB value. The boards with treated particles gave better performance in terms of physical properties. There were no significant differences in mechanical properties (MOR, MOE and IB) and physical properties for the different alkali treatment. The values of bending strength and IB strength increased with an increase in resin content, while TS and WA increased with a decrease in resin content. In conclusion, NaOH and KOH treated kenaf particles improved board performance and could be considered as an alternative material for particleboard production.


2013 ◽  
Vol 20 (4) ◽  
pp. 337-342 ◽  
Author(s):  
Halil Turgut Sahin ◽  
Mustafa Burak Arslan

AbstractApple and cherry pruning with red pinewood particles in various proportions were used as the raw material for the experimental particleboard manufacturing in laboratory conditions. The results showed that there were no considerable differences in the main chemical constituents of carbohydrate and lignin content, although there were some differences found for extractives that are considerably higher for both cherry and apple pruning. The mean modulus of rupture values of boards were found to ranged from 12.4 to 18.48 MPa. These indicated that all the boards, except for the board type F (prepared from 100% apple pruning), met the minimum bending strength required in standard for general-purpose particleboards. The modulus of elasticity and internal bond of the experimental particleboards usually decreased as red pinewood particle content decreases in proportion. However, all the boards produced in this study met the minimum modulus of elasticity, internal bond, and surface strength required in standard for general-purpose particleboards. However, the thickness swelling for 24 h was considerably higher than the required in standard value of 14% for all boards.


BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6550-6560
Author(s):  
Lawrence Aguda ◽  
Babatunde Ajayi ◽  
Sylvester Areghan ◽  
Yetunde Olayiwola ◽  
Aina Kehinde ◽  
...  

Declining availability of the prime economic species in the Nigerian timber market has led to the introduction of Lesser-Used Species (LUS) as alternatives. Their acceptability demands information on the technical properties of their wood. The aim of this study was to investigate the mechanical properties of Ficus vallis-choudae to determine its potential for timber. Three mature Ficus vallis-choudae trees were selected and harvested from a free forest area in Ibadan, Oyo State, Nigeria. Samples were collected from the base (10%), middle (50%), and top (90%) along the sampling heights of each tree, which was further partitioned into innerwood, centrewood, and outerwood across the sampling radial position. Investigations were carried out to determine the age, density, moisture content, impact strength, modulus of elasticity, modulus of rupture, compressive strength parallel-to-grain, and shear strength parallel-to-grain. The mean impact bending strength, modulus of rupture, modulus of elasticity, maximum shear strength parallel-to-grain, and maximum compression strength parallel-to-grain for Ficus vallis-choudae at 12% moisture content were 20.4 N/mm2, 85.8 N/mm2, 709 N/mm2, 10.7 N/mm2, and 33.6 N/mm2, respectively. The study found the species to be dense with high strength properties in comparison with well-known timbers used for constructional purposes.


2012 ◽  
Vol 517 ◽  
pp. 683-688 ◽  
Author(s):  
Wan Li Lou ◽  
Hai Qing Ren ◽  
Zhao Hui Wang ◽  
Xiu Qin Luo

Larch dimension lumber bending strength properties from full-size bending test were used to establish preliminary grade boundary settings for mechanical grading of lumber by modulus of elasticity. Simulated production using the grade boundary settings were evaluated for modulus of rupture, ultimate tensile strength, and ultimate compressive strength. The results showed a good relationship between modulus of rupture and modulus of elasticity, and the observed relationships between strengths properties were consistent with that assumed for the standard grades. Through mechanical grading, larch dimension lumber could be sort grades: M14, M30 and M40. Assuming the visual requirements are met, the M30 and M40 grades account for more than 80% of the total production. Mechanical grading of larch appears to be a viable approach for grading Chinese large for structural applications.


2018 ◽  
Vol 15 (3) ◽  
Author(s):  
J Weber ◽  
A Stollenwerk

The choice of materials used to build a laminate recurve bow is crucial to optimizing performance. To this end, a low-cost bending tester was designed and built to measure the flexural modulus and modulus of rupture on a variety of wooden laminates. To gain a better understanding of the relationship between the properties of the laminates and the individual species comprising the laminates, woods with a wide range of elastic and strength properties were chosen. Differences between the expected and experimental results are attributed to the properties of the adhesive and defects in the wood. KEYWORDS: bending test; recurve bow; wood; laminates; modulus of rupture; flexural modulus


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lukas Emmerich ◽  
Christian Brischke ◽  
Susanne Bollmus ◽  
Holger Militz

Abstract Cyclic N-methylol compounds have been used for cell wall impregnation modifications of wood. Besides an improved decay resistance and dimensional stability, the modifications resulted in a decrease of wood’s dynamic strength properties. However, the mechanisms behind a significant loss in dynamic strength are not fully understood yet. In this study, wood blocks were treated with the N-methylol compounds 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) and methylated DMDHEU (mDMDHEU) and the N-methyl compound 1,3-dimethyl-4,5-dihydroxy-ethyleneurea (DMeDHEU). In order to study the factors that control the changes of wood performance under dynamic loads, single (impact bending strength, IBS) and multiple dynamic impact (resistance to impact milling, RIM) tests were applied. It became evident, that reductions in IBS and RIM increased with increasing solid content, formaldehyde content and catalyst concentration of the impregnation solutions, but were not affected by a cold-water leaching. Differences in structural integrity of wood modified with N-methylol and N-methyl compounds were more pronounced than those of IBS. Therefore, RIM appeared more sensitive to changes on cellular level, as a higher degree of co-condensation of the N-methylol compounds with cell wall polymers was expected in comparison with the N-methyl compound.


2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hüseyin Pelit ◽  
Fatih Emiroglu

AbstractIn this study, the effect of thermo-mechanical densification on the density, hardness, compression strength, bending strength (MOR), and modulus of elasticity (MOE) of fir and aspen wood pretreated with water repellents was analyzed. Wood specimens were impregnated with paraffin, linseed oil and styrene after pre-vacuum treatment. Then, the impregnated wood specimens were densified with compression ratios of 20 and 40%, and at 120, 150 and 180 °C. The results indicated that the density, hardness and strength properties of the all densified specimens (untreated and impregnated) increased depending on the compression ratio and temperature. For all tested properties, higher increases were obtained in the paraffin and styrene pretreated specimens compared to untreated samples. However, the increase rates in linseed oil pretreated specimens were generally lower than untreated specimens. Regarding water repellents the most successful results in all tested properties were determined in styrene pretreated specimens. The density, hardness and strength properties of all specimens increased with the increase in compression ratio. On the other hand, the increase in the compression temperature negatively affects the properties of untreated and linseed oil pretreated specimens, while having a generally positive effect on the properties of paraffin pretreated specimens. However, all tested properties of styrene pretreated specimens have increased significantly due to the increase in compression temperature. The increasing strength properties of wood as a result of densification have increased much more with paraffin and especially styrene pretreatment. These combinations can be considered as an important potential for applications that require more hardness and strength.


2020 ◽  
Vol 5 (1) ◽  
pp. 711-725
Author(s):  
Sutrisno ◽  
Eka Mulya Alamsyah ◽  
Ginanjar Gumilar ◽  
Takashi Tanaka ◽  
Masaaki Yamada

AbstractThe properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.


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