Effect of Thermal Modification Treatment on Some Physical and Mechanical Properties of Pinus oocarpa Wood

This study deals with the effect of heat treatment on Pinus oocarpa specimens from forest plantations in Colombia. The effects of two heat treatments at 170 and 190 °C for 2.5 h in saturated vapor were evaluated based on the color, dimensional stability, air-dry and basic densities, modulus of elasticity (MOE), and modulus of rupture (MOR) in static bending of samples. The evaluations were carried out following the Colombian Technical Standards NTC 290 and 663, and the color changes resulting from heat treatments were monitored using the CIE-Lab, as well as other standards from the literature. The results show that there was 2.4% and 3.3% mass loss of wood modified at 170 and 190 °C, respectively. The air-dry and basic densities were higher in 170 °C treatment than after 190 °C treatment, and the thermal modifications applied increased the dimensional stability of the treated wood. After treatment at 170 and 190 °C, the lightness to darkness (L*) was reduced by 10% and 22%; the a* coordinate increased by 11% and 26%, causing redness in the treated wood; the b* coordinate increased by 14% and 17%; and the values of the wood color saturation (c*) increased by 14% and 18%, respectively. The general color change (ΔE*) increased gradually with the increase in the treatment temperature, resulting in a high color change to a very different color. The bending strength of thermally modified wood was improved and significantly increased to values higher than those of unmodified Pinus oocarpa wood. The high air-dry and basic densities, improved dimensional stability and resistance to bending, and attractive appearance of the treated wood indicate that thermal modification is a promising alternative for the transformation of Pinus oocarpa wood into a raw material with a high added value.

Download Full-text

Effect of Moderate Temperature Thermal Modification Combined with Wax Impregnation on Wood Properties

Applied Sciences ◽

10.3390/app10228231 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8231

Author(s):

Jing-Wen Zhang ◽

Hong-Hai Liu ◽

Lin Yang ◽

Tian-Qi Han ◽

Qin Yin

Keyword(s):

Mechanical Strength ◽

Dimensional Stability ◽

Color Change ◽

Strength Loss ◽

Wood Properties ◽

Thermal Modification ◽

Moderate Temperature ◽

Modulus Of Rupture ◽

Internal Surfaces ◽

Higher Temperature

Thermal modification (TM) improves the hydrophobicity, dimensional stability, and durability of wood, but TM commonly results in severe color change and mechanical strength loss as wood is treated at higher temperature. In this study, Pterocarpus macrocarpus Kurz wood was thermally modified at moderate temperature (150 °C) and higher temperature (200 °C), and subsequently TM wood at 150 °C was subjected to wax impregnation (WI), the effect of a combination of TM and WI on the hygroscopicity, dimensional stability, and mechanical properties, as well as the micro-structure of wood, were investigated and compared. The results showed that the mass loss of wood was slight at 150 °C TM, while it became severe at 200 °C TM conditions. TM conditions affected the amount of the subsequent wax impregnation; the equilibrium moisture content (EMC), water absorption ratio, and adsorption and absorption swelling of the 150 °C TM + WI group were lower than that of 200 °C TM, and presented the lowest value. Moderate temperature TM could improve the hydrophobicity and dimensional stability of wood, but WI played a key role in the improvement. TM decreased the modulus of rupture (MOR) of wood, while WI improved the MOR. TM increased the modulus of elasticity (MOE) of wood, but WI had little effect on MOE; Scanning electron microscope (SEM) observation showed that the wax was successfully impregnated into the wood interior, and presented an even distribution on the internal surfaces of wood cells; Fourier-transform infrared spectroscopy (FTIR) spectra verified the changes of –OH and C=O after TM and TM + WI, which contributed to decreasing hygroscopicity and improving the dimensional stability of the wood. Impregnated wax improved wood mechanical strength, but decreased the lightness, and deepened the color of wood. The combination of thermal modification at moderate temperature with subsequent wax impregnation is a practical approach for improving wood properties.

Download Full-text

Temperature’s effect on color change and mechanical properties of poplar powder compact formed by warm compaction

BioResources ◽

10.15376/biores.15.3.7009-7017 ◽

2020 ◽

Vol 15 (3) ◽

pp. 7009-7017

Author(s):

Liqiang Zhang ◽

Zhizhong Long ◽

Zhili Tan ◽

Qingding Wu

Keyword(s):

Mechanical Properties ◽

Color Change ◽

Chemical Properties ◽

Added Value ◽

Modulus Of Rupture ◽

Surface Color ◽

Warm Compaction ◽

Infrared Spectral ◽

Forming Temperature ◽

Color Control

Warm compaction technology is an eco-friendly method to improve the added value of poplar. In this work, the wood powder was compacted in the mold between 120 °C to 200 °C, at 80 MPa for 30 min. The color change, chemical properties, and mechanical properties were evaluated. The color of the formed compaction darkened uniformly. The CIE lightness color coordinate (L*) and chroma coordinates a* and b* decreased with the increase of forming temperature. Fourier infrared spectral analysis showed degradation of carbohydrates, along with the formation of a new chemical structure of darker color. Mechanical properties including modulus of rupture (MOR) and modulus of elasticity (MOE) of compacted wood increased initially and then decreased. These results provide a reference for the surface color control of thermally forming materials.

Download Full-text

PHYSICAL PROPERTIES OF WOOD Pinus caribaea var. caribaea, Pinus caribaea var. hondurensis AND Pinus oocarpa FOR PENCIL PRODUCTION

FLORESTA ◽

10.5380/rf.v51i2.68955 ◽

2021 ◽

Vol 51 (2) ◽

pp. 354

Author(s):

Pedro Lício Loiola ◽

Ricardo Jorge Klitze ◽

Márcio Pereira Rocha ◽

Graziela Baptista Vidaurre

Keyword(s):

Physical Properties ◽

Dimensional Stability ◽

Industrial Sector ◽

Raw Material ◽

Brazilian Cerrado ◽

Pinus Caribaea ◽

Specific Mass ◽

Mass Properties ◽

Pinus Oocarpa ◽

Alternative Species

The behavior of the physical properties of wood is important for its use in the industrial sector. Manufacturing for pencil production requires raw material with low specific mass and high dimensional stability. The objective of this study was to evaluate the properties of the physical specific basic mass properties, anhydrous and green, as well as the retractability of the 14 years old Pinus caribaea var. caribaea, 25 years old Pinus caribaea var. hondurensis and 35 years old Pinus oocarpa in the medulla sense of the bark, base and top of the trees. All species come from the Brazilian Cerrado region afforestation. As for dimensional stability, the Pinus caribaea var. caribaea and Pinus oocarpa had similar behaviors to the volumetric contraction, when evaluating the coefficient of anisotropy of wood species of Pinus caribaea var. caribaea had higher values of anisotropy coefficient, however, all tropical pine studied, qualify as a raw material for the pencil industry, being an alternative species traditionally used.

Download Full-text

Hydrothermal Modification of Wood: A Review

Polymers ◽

10.3390/polym13162612 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2612

Author(s):

Md. Rowson Ali ◽

Ummi Hani Abdullah ◽

Zaidon Ashaari ◽

Norul Hisham Hamid ◽

Lee Seng Hua

Keyword(s):

Mechanical Properties ◽

Dimensional Stability ◽

Elevated Temperatures ◽

Chemical Properties ◽

Treated Wood ◽

Decay Resistance ◽

Acoustic Properties ◽

Buffer Solution ◽

Promising Alternative ◽

Hydrothermal Modification

Wood is a versatile material that is used for various purposes due to its good properties, such as its aesthetic properties, acoustic properties, mechanical properties, thermal properties, etc. Its poor dimensional stability and low natural durability are the main obstacles that limit its use in mechanical applications. Therefore, modification is needed to improve these properties. The hydrothermal modification of wood exposes wood samples to elevated temperatures and pressure levels by using steam, water, or a buffer solution as the treating medium, or by using superheated steam. Abundant studies regarding hydrothermally treated wood were carried out, but the negative effect on the wood’s strength is one of the limitations. This is a method that boosts the dimensional stability and improves the decay resistance of wood with minimal decrements of the strength properties. As an ecofriendly and cost-effective method, the hydrothermal modification of wood is also a promising alternative to conventional chemical techniques for treating wood. Researchers are attracted to the hydrothermal modification process because of its unique qualities in treating wood. There are many scientific articles on the hydrothermal modification of wood, and many aspects of hydrothermal modification are summarized in review papers in this field. This paper reviews the hydrothermally modified mechanical properties of wood and their potential applications. Furthermore, this article reviews the effects of hydrothermal modification on the various properties of wood, such as the dimensional stability, chemical properties, and durability against termites and fungi. The merits and demerits of hydrothermal wood modification, the effectiveness of using different media in hydrothermal modification, and its comparison with other treating techniques are discussed.

Download Full-text

Yield in eucalyptus slab for use in the obtainment of battens

FLORESTA ◽

10.5380/rf.v48i1.47286 ◽

2018 ◽

Vol 48 (1) ◽

pp. 19

Author(s):

Claudio Gumane Francisco Juizo ◽

Douglas Edson Carvalho ◽

Pedro Lício Loiola ◽

Márcio Pereira Da Rocha ◽

Ricardo Jorge Kliztke ◽

...

Keyword(s):

Specific Gravity ◽

Dimensional Stability ◽

Raw Material ◽

Added Value ◽

Class 1 ◽

Band Saw

The present work aimed to evaluate the yield in eucalyptus slabs for obtaining battens to be used as raw material in the production of higher added value products. For this purpose, 15 logs of E. grandis and 15 logs of E. saligna, which were separated into three diametric classes of five logs for each species, were used: diametric class 1 (25 - 32 cm), diametric class 2 (33- 39 cm) and diametric class 3 (> 40 cm). Afterwards, they were cubed and evaluated for their taper, and were deployed on a band saw. The slabs were removed to evaluate the quality, yield and yield of slabs obtained for each species studied. The obtained results indicated that a medium classification of the specific gravity obtained, with good dimensional stability of E. grandis and E. saligna wood. The taper of the logs and the yields observed were not significant in both species. However, the yields in slabs and yields in battens had a slight decrease by the increasing of the diameters of the logs. Thus, logs with greater yield in slabs had smaller yields in battens. Therefore, it is possible to use slabs for battens production mainly in the industries that process high amounts of logs.

Download Full-text

Mechanical and Physical Properties of Particle Board Made from Silaned and NaOH Modified Kelampayan (Neolamarckia cadamba) Particles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.812.169 ◽

2013 ◽

Vol 812 ◽

pp. 169-174

Author(s):

Azizul Ishak ◽

Siti Rafedah A. Karim ◽

Hashim W. Samsi

Keyword(s):

Physical Properties ◽

Dimensional Stability ◽

Internal Bond ◽

Bending Strength ◽

Treated Wood ◽

Raw Material ◽

Medium Density ◽

Bond Properties ◽

Particle Board ◽

Mechanical And Physical Properties

The objective of this study is to determine the mechanical and physical properties of Particleboard made from modified particle of Kelampayan (Neolamarckia cadamba). The particles were modified with Silane and Sodium Hydroxide (NaOH) by soaked the particle for 24 hours with different ratio ( Kelampayan + Silane, Kelampayan + NaOH, and Kelampayan + Silane + NaOH). The result showed that the mechanical and dimensional stability of the treated wood were improved. Particleboard made from 0.8 mesh particles treated with Silane and NaOH were highest value of bending strength modulus of rapture (MOR) 22.89MPa, modulus of elasticity (MOE) 3916.88MPa and Internal Bond properties 0.48214 MPa whereby particleboard made from 0.5 mesh particles treated by Silane were highest value for bending strength (MOR) 15.75MPa, MOE 2905.34 and Internal Bond properties 0.5748MPa.Outcome of this proposed research will provided valuable databases to the wood based industry to use Kelampayan as an alternative raw material in their down streams production such as particleboard, medium-density board and chipboard manufacturing.

Download Full-text

PEMANFAATAN LIMBAH SABUT KELAPA ( Cocos nucifera L) DAN SERAT TANDAN KOSONG KELAPA SAWIT (Elais guineensis JACQ) SEBAGAI KOMBINASI BAHAN BAKU PEMBUATAN PAPAN PARTIKEL

ZIRAA'AH MAJALAH ILMIAH PERTANIAN ◽

10.31602/zmip.v44i1.1724 ◽

2019 ◽

Vol 44 (1) ◽

pp. 106

Author(s):

Adam Maulana ◽

Udiantoro Udiantoro ◽

Lya Agustina

Keyword(s):

Oil Palm ◽

Raw Materials ◽

Cocos Nucifera ◽

Raw Material ◽

Added Value ◽

Modulus Of Rupture ◽

Particle Board ◽

Coconut Fiber ◽

Randomized Design ◽

Cocos Nucifera L

The utilization of coconut fiber that has not been optimal is one of the opportunities so that the waste has added value, one of which is to process it into particle board. Objective research is to best composition particle board making from coconut coir waste material and TKKS to produce qualified particle board. The method used was a complete randomized design (RAL) with 3 treatment, single factor treatment ie the composition of raw materials in the form of coconut husk and TKKS. Comparison of the particle-making composition of particle board P0: 100% coco fiber: 0% of oil palm empty bunch fibers, P1: 75% : 25%, P2: 50% : 50%, P3: 25% : 75%, P4: 0% : 100%. Best results the combination of raw material composition of particle board is in the treatment of P0 (100% coco fiber: 0% of oil palm empty bunch fiber) with a density value of 0.43 g / cm³, moisture content 7.0%, Modulus of Elasticity - MoE 2.037.45 kg / cm2 and the Modulus of Rupture - MoR 46.14 kg / cm².

Download Full-text

DECAY RESISTANCE, DIMENSIONAL STABILITY AND MECHANICAL STRENGTH OF POPLAR WOOD MODIFIED WITH PLANT-DERIVED COMPOUNDS

Wood Research ◽

10.37763/wr.1336-4561/66.4.556568 ◽

2021 ◽

Vol 66 (4) ◽

pp. 556-568

Author(s):

JIAPENG WANG ◽

ZHENJU BI ◽

ZHANGJING CHEN ◽

LI YAN ◽

YAFANG LEI

Keyword(s):

Mechanical Properties ◽

Citric Acid ◽

Dimensional Stability ◽

Color Change ◽

White Rot Fungi ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

Modulus Of Rupture ◽

Weight Percentage

The cinnamaldehyde, salicylic acid, stearolic acid and citric acid were plant-derived organic compounds that can be activated to fungi, that could degrade the wood in long term. The compounds with concentrations of 3%, 5% and 7% assisted by different dispersants were impregnated into poplar (Populus nigra L.) specimens by the vacuum-pressure method. After that, weight percentage gain (WPG), decay resistance against white-rot fungi (Trametes versicolor) and brown-rot fungi (Gloeophyllum trabeum), color change, dimensional stability and mechanical properties including modulus of elasticity (MOE) and modulus of rupture (MOR) were measured. The results indicated that cinnamaldehyde impregnated poplar showed antifungi activity against both G. trabeumand T. versicolor, and citric acid impregnated poplar showed antifungi activity against G. trabeum. The color of poplar specimens before and after impregnated cinnamaldehyde and citric acid had a little change, dimensional stability had been improved and mechanical properties especially for MOR increased significantly.

Download Full-text

Physical and Mechanical Properties of Heat Treated Daniella oliveri (Africa Balsam Tree) Wood

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2019/v35i230175 ◽

2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Ebenezer Adeyemi Iyiola ◽

Babatola Olufemi ◽

Victoria Olubukola Oyerinde ◽

J. M. Owoyemi ◽

Ayanleye Samuel

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Compressive Strength ◽

Study Design ◽

Dimensional Stability ◽

Treated Wood ◽

Physical And Mechanical Properties ◽

Thermal Modification ◽

Average Weight ◽

Direction Parallel

Aims: This work investigated the effect of thermal modification on some of the physical properties and mechanical properties of Daniella oliveri wood. Study Design: The study design used for this experiment was 3 x4 Factorial experiment in Completely Randomized Design. Place and Duration of Study: The study was conducted at the Federal University of Technology, Akure wood laboratory and the study lasted for 6 months. Methodology: Wood samples were thermally treated at the temperature of 120, 140, 160 and 180°C, for different durations of 1, 1.5 and 2 hours in a muffle furnace. The planks were air-dried to reduce the moisture content and then machined into the required dimensions in the direction parallel to grain with a circular saw. Thirty-nine defect-free samples of dimensions 20 mm × 20 mm × 60 mm were prepared for dimensional stability and compression test, static bending tests and the hardness tests to make a total of 117 samples. Results: The result showed that the average weight loss of the treated wood samples varied from 3.79% at 120°C for 1 hour to 7.51% at 180°C for 2 hours. The treatment led to reduction in density from 528 to 459 kg/m3 at 180°C for 2 hours. The heat treatment also led to reduction in water absorption and volumetric swelling of the treated samples. The mean value for Modulus of elasticity (MOE) ranges from 2.17x103 N/mm2 to 2.96 x 103 N/mm2 for the treated samples while the untreated was 2.22x103 N/mm2. Heat treatment brought about improvement in the maximum compressive strength and the Janka hardness parallel to the grain of wood samples. The value of compressive strength increased from 26.58 N/mm2 to 41.71 N/mm2 and hardness from 69.24 N to 75.5 N. It can therefore be concluded that thermal modification greatly enhanced the dimensional stability and mechanical properties of wood samples.

Download Full-text

Effect of Heat Treatment on the Physic-Mechanical Characteristics of Eucalyptusurophylla S.T. Blake

Materials ◽

10.3390/ma14216643 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6643

Author(s):

Lin Yang ◽

Honghui Jin

Keyword(s):

Dimensional Stability ◽

Color Change ◽

Chemical Change ◽

Water Vapor Adsorption ◽

Moderate Temperature ◽

Modulus Of Rupture ◽

Dry Density ◽

Hydroxyl Groups ◽

Eucalyptus Urophylla ◽

Wood Color

Eucalyptus plantations wood have great potential application in high quality solid wood product. In order to improve the overall characteristics, heat treatments (HT) were carried out using Eucalyptus urophylla S.T. Blake wood at 150, 170 and 190 °C, for 2 and 4 h, separately. The effects of HT on physical and mechanical properties, wood color, dimensional stability and chemical change were investigated. The results indicate that: Mass loss (ML) of wood at a moderate temperature of 150 °C was small, but increased remarkably when temperature exceeds 170 °C. A maximum ML of 5.83% was observed at 190 °C/4 h; the velocity of water vapor adsorption and equilibrium moisture content (EMC) of HT wood decreased significantly, and varied considerably with treating severity; absolute dry density of HT wood decreased, presenting a similar tendency with ML, but the reduction was greater than ML; HT reduced the tangential and radial swelling ratio and swelling coefficients of wood, and improved the dimensional stability by 71.88% at 190 °C; modulus of rupture (MOR) and modulus of elasticity (MOE) of HT wood varied significantly in severer conditions, but there were no obvious changes in a moderate conditions at 150 °C; there was a slight color change at 150 °C, but wood color became more dark and uniform with treating severity; HT decreased the relative content of hydroxyl groups in wood components, improving wood dimensional stability. Color change of wood may be caused by variations of chromophoric groups and its own structure of lignin due to HT. Moderate temperature HT at 150 °C improved dimensional stability and color uniform of wood, but without reducing mechanical stress. This is a practical HT condition for Eucalyptus urophylla S.T. Blake.

Download Full-text