scholarly journals EFFECT OF THERMO-MECHANICAL TREATMENT ON PROPERTIES OF PARICA PLYWOODS (Schizolobium amazonicum Huber ex Ducke)

2017 ◽  
Vol 41 (1) ◽  
Author(s):  
Mírian de Almeida Costa ◽  
Cláudio Henrique Soares Del Menezzi

ABSTRACT Thermo-mechanical treatment is a technique for wood modification in which samples are densified by means of heat and mechanical compression, applied perpendicularly to fibers, which under different combinations of time, temperature, and pressure increases wood density and thus improve some of its properties. This study aimed to treat thermo-mechanically parica plywood and observe the effects on its physical and mechanical properties. Specimens were submitted to two treatments, 120 and 150 ºC, remaining under pressure for seven minutes and, subsequently, under zero pressure for 15 minutes. Results showed a significant increase in specific mass from 0.48 g cm-3 to an average of 0.56 g cm-3, and a compression ratio of about 31.7% on average. Physical properties also varied significantly and results showed that treated samples swelled and absorbed more water than those untreated, leading to a greater thickness non-return rate. This indicates the proposed thermal treatments did not release the internal compressive stress generated during panel pressing, not improving its dimensional stability as a result. On the other hand, mechanical properties were positively affected, leading to an increase of 27.5% and 51.8% in modulus of rupture after treatments at 120 and 150 ºC, respectively. Modulus of elasticity and glue-line shear strength did not vary statistically and Janka hardness was 29.7% higher after treatment at 150 ºC.

2021 ◽  
Vol 891 (1) ◽  
pp. 012007
Author(s):  
Y S Hadi ◽  
E N Herliyana ◽  
I M Sulastiningsih ◽  
E Basri ◽  
R Pari ◽  
...  

Abstract Jabon (Anthocephalus cadamba) laminas were impregnated with polystyrene and reached 21.2% polymer loading. The laminas were manufactured for three-layer glued laminated timber (glulam) using isocyanate glue with glue spread 280 g/m2 and cold-press process. For comparison purposes, untreated glulam as control and also solid wood were prepared. The physical-mechanical properties were evaluated according to the Japanese Agricultural Standard (JAS) 234-2003. The results showed that the color of glulam was not different from polystyrene glulam. The density of polystyrene glulam was higher than untreated glulam and solid wood, but the moisture content was lower than the other. The product kinds of solid wood, untreated glulam, and polystyrene glulam did not affect shear strength and modulus of rupture (MOR), while the modulus of elasticity (MOE) of untreated glulam and hardness of polystyrene glulam were the highest values and the other products were not different one each other. Both kinds of glulam fulfilled the Japanese standard in terms of moisture content, MOR, and delamination in hot water, but MOE and shear strength did not. Regarding its advantages, polystyrene glulam could be further developed using a higher wood density.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9596-9610
Author(s):  
Yali Shao ◽  
Lili Li ◽  
Zhangjing Chen ◽  
Sunguo Wang ◽  
Ximing Wang

Poplar (Populus) wood was subjected in this work to thermo-hydro-mechanical treatment. The influence of the treatment parameters on the physical and mechanical properties were investigated. The wood samples were densified under three compression ratios (0%, 30%, and 50%), and thermally treated at three temperatures (180 °C, 200 °C, and 220 °C), at three thermal treatment durations (3 h, 4 h, and 5 h). The density, modulus of elasticity, modulus of rupture, radial hardness, and thickness swelling were measured. The results showed that the densities of the samples increased by 36.6% to 49.7%. As the compression rate increased, the temperature, duration, modulus of elasticity, modulus of rupture, and hardness increased. However, the dimensions of the densified samples were less stable. Compared to the densified samples, the maximum thickness swelling could be reduced by 74% (from 29.7% to 7.8%) when subjected to a thermal treatment at 220 °C for 3 h.


2015 ◽  
Vol 50 (3) ◽  
pp. 189-192 ◽  
Author(s):  
SA Shanu ◽  
AK Das ◽  
MM Rahman ◽  
M Ashaduzzaman

This experiment was carried out to analyze the effects of CCB (chromate-copper-boron) preservative treatment on physical and mechanical properties of Albizia richardiana wood using dipping method. Retention of preservative was maximum at 8% concentration of the preservatives. Based on the retention at this concentration, the physical and mechanical properties of the treated wood were examined. The density of untreated A. richardiana wood was 521 kg/m3. It changed to 542 kg/m3 on treatment. This increase in density by 2.30% for treated wood was significant. On the other hand, modulus of rupture (MOR) increased significantly from 93 to 107 N/mm2 on treatment of the wood. The modulus of elasticity (MOE) increased from 3205 to 4861 N/mm2. Physical and mechanical properties of the wood improved by treating with CCB preservative.Bangladesh J. Sci. Ind. Res. 50(3), 189-192, 2015


CORD ◽  
2013 ◽  
Vol 29 (1) ◽  
pp. 4
Author(s):  
Izran K.

A study was undertaken to investigate the physical and mechanical properties of engineered coconut (Cocos nucifera) veneer (ECTV). The coconut trunks (40 – 50 years old) were obtained from Hutan Melintang, Perak and were peeled into veneers at Bestgrade Sdn. Bhd. The veneers were obtained from two different parts of coconut trunks viz inner and outer which were used to fabricate 5-ply engineered coconut veneers. The ECTVs were fabricated at FRIM’s Bio-Composite Laboratory. They were manufactured with urea formaldehyde (UF) resin and with three combinations namely 100% inner, 100% outer and alternate outer & inner veneers (mix). The densities for the engineered veneers made of 100% outer, 100% inner, and mixed layers were 944.1 kg/m3, 858.15 kg/m3 and 891.11 kg/m3, respectively. Results showed that the Modulus of Rupture (MOR) of the ECTV made from 100% outer veneers had the highest mean MOR value (88.69 MPa), followed by those made from the mixed veneers (74.35 MPa) and 100% inner (58.44 MPa), respectively.  On the other hand, the Modulus Of Elasticity (MOE) values were 10.12 Mpa for outer, 8,210 Mpa for inner and 10,075 Mpa for mixed. Overall, the testing results showed that the ECTV met the standard requirements.


Author(s):  
L.E. Murr

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.


2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.


2012 ◽  
Vol 576 ◽  
pp. 314-317
Author(s):  
Sinin Hamdan ◽  
M. Saiful Islam

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Chatree Homkhiew ◽  
Surasit Rawangwong ◽  
Worapong Boonchouytan ◽  
Wiriya Thongruang ◽  
Thanate Ratanawilai

The aim of this work is to investigate the effects of rubberwood sawdust (RWS) size and content as well as the ratio of natural rubber (NR)/high-density polyethylene (HDPE) blend on properties of RWS reinforced thermoplastic natural rubber (TPNR) composites. The addition of RWS about 30–50 wt% improved the modulus of the rupture and tensile strength of TPNR composites blending with NR/HDPE ratios of 60/40 and 50/50. TPNR composites reinforced with RWS 80 mesh yielded better tensile strength and modulus of rupture than the composites with RWS 40 mesh. The TPNR/RWS composites with larger HDPE content gave higher tensile, flexural, and Shore hardness properties and thermal stability as well as lower water absorption. The TPNR/RWS composites with larger plastic content were therefore suggested for applications requiring high performance of thermal, physical, and mechanical properties.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
. Erma ◽  
Fadiilah H Usman ◽  
. Muflihati

Physical and mechanical properties of wood is one of the basic properties that need to be known in the selection of wood, because the physical and mechanical properties of wood are not the same height on the stem. Increased wood demand gives the opportunity to use wood that is not yet known for its marketing, one of which is Salam wood (Syzygium polianthum (Wight) Walp). The purpose of this research was to determine the physical and mechanical properties of Salam wood based on the height of the stem so that Salam wood can be optimally utilized by testing based on Classification SNI – 5 PKKI 1961. Methods of making test and test examples based on British Standard Methods No. 373-1957. The results showed that Salam wood has physical properties with an average  brown colour, the moisture content 3,13 % , density  0,58 kg/cm2 , Depreciation 2,59 %. Salam has mechanical properties with an average height position stem from base to tip with Modulus of Elastiscity (MOE)  97.701,54 , Modulus of Rupture (MOR) 659,18  and  Modulus Crushing  Streang 342,86 . Salam can be classified into strong class III and based on its properties and mechanics, it is suitable for use as a lightweight construction and furniture.Keywords: Density, depreciation, MCS, MOE, moisture content, MOR


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