Effect of oil heating age on colour and dimensional stability of heat treated Pinus radiata

Abstract Pinus radiata wood specimens were heat-treated at 160–210°C in linseed oil and the effects of treatment on chemical composition, color, dimensional stability, and fungal resistance were examined. The degradation of hemicelluloses was the most remarkable feature, which is the principal reason for alterations in wood properties. Removal or migration of extractives, oil uptake and the accumulation of oil on the wood surface were observed. The color of heat-treated wood became more uniform and darker, and its dimensional stability (i.e., anti-swelling efficiency) and fungal resistance were improved by up to 60% and 36%, respectively. The viscosity of the oil after treatment was elevated with the treatment temperature and was higher in comparison to heated oil without wood present.

Download Full-text

Structure, Mechanical Performance, and Dimensional Stability of Radiata Pine (Pinus radiata D. Don) Scrimbers

Advances in Polymer Technology ◽

10.1155/2019/5209624 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Jinguang Wei ◽

Fei Rao ◽

Yuxiang Huang ◽

Yahui Zhang ◽

Yue Qi ◽

...

Keyword(s):

Mechanical Properties ◽

Pinus Radiata ◽

Dimensional Stability ◽

High Performance ◽

Water Resistance ◽

Mechanical Performance ◽

Three Dimensional ◽

Radiata Pine ◽

Specific Strength ◽

Shearing Strength

Natural wood has certain advantages such as good processability and high specific strength and thus has been used for millennium as a structural material. But the mechanical performance and water resistance, particularly for fast-growing species, are unsatisfactory for high-end applications. In this study, the “new-type” scrimber technology was introduced to radiata pine (Pinus radiata D. Don) scrimbers. The structure, mechanical properties, and dimensional stability of the scrimber panels were investigated. Results showed that OWFMs as basic units of scrimber had been very even in size and superior permeability. The scrimbers exhibited a three-dimensional porous structure, and the porosity had a decrease with increasing density. Both OWFMs and densification contributed to the high performance in terms of mechanical properties and water resistance. The flexural, compressive, and short-beam shearing strength were significantly enhanced with increasing density. As the density was 0.80 g cm−3, the flexural strength (MOR) was approximately 120 MPa, much larger than many selected wood-based panels. Moreover, the water resistance and dimensional stability also were closely related to the density. At the density of 1.39 g cm−3, the water absorption rate and thinness swelling rate of the panels in boiled water were only 19% and 5.7%, respectively.

Download Full-text

Dimensional stability and creep behavior of heat-treated exterior medium density fiberboard

European Journal of Wood and Wood Products ◽

10.1007/s00107-009-0311-7 ◽

2009 ◽

Vol 67 (3) ◽

pp. 287-295 ◽

Cited By ~ 19

Author(s):

Nadir Ayrilmis ◽

Theodore L. Laufenberg ◽

Jerrold E. Winandy

Keyword(s):

Creep Behavior ◽

Dimensional Stability ◽

Medium Density Fiberboard ◽

Medium Density ◽

Heat Treated

Download Full-text

Promotion effect of NP fire retardant pre-treatment on heat-treated poplar wood. Part 1: color generation, dimensional stability, and fire retardancy

Holzforschung ◽

10.1515/hf-2016-0082 ◽

2017 ◽

Vol 71 (3) ◽

pp. 207-215 ◽

Cited By ~ 9

Author(s):

Demiao Chu ◽

Jun Mu ◽

Li Zhang ◽

Yushuang Li

Keyword(s):

Dimensional Stability ◽

Treatment Time ◽

Fire Hazard ◽

Fire Retardant ◽

Surface Color ◽

Heat Treated ◽

Combustion Properties ◽

Long Time ◽

Pre Treatment ◽

Wood Part

Abstract Heat treatment (HT) enhances various properties of wood (W), but it takes a relatively long time and WHT is a source of fire hazard. To improve the properties of WHT, Populus beijingensis W. Y. Hsu wood was impregnated with nitrogen-phosphorus (NP) fire retardant (10% aqueous solution) and the effects of the combined NP treatment and HT were observed. Control groups included native wood and samples from WHT200°C, 120 min and WHT220°C, 120 min. The surface color, dimensional stability, and combustion properties of the treated samples were examined. NP pre-treatment intensified the effectivity of HT150°C, where the treatment time decreased by 75%. The decomposition and catalytic dehydration of NP treatment enhanced the dimensional stability and darkened the wood surface. After HT, the NP fire retardant was transformed from dispersive particles into a uniform layer on the inner surfaces of wood. The heat release rate (HRR) decreased by 60.3% and the residual mass (RM) increased by 61.1% in WNP, HT compared to normal WHT200°C poplar.

Download Full-text

Physical and Mechanical Properties of Five Heat-Treated Hardwood Species

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.1132 ◽

2012 ◽

Vol 472-475 ◽

pp. 1132-1134

Author(s):

Jin Sun ◽

Xiao Bo Wang ◽

Xiao Jing Wang ◽

Yan Lin ◽

Zhen Zhong Gao

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Dimensional Stability ◽

Negative Impact ◽

Physical And Mechanical Properties ◽

Betula Platyphylla ◽

Fraxinus Mandshurica ◽

Hardwood Species ◽

Heat Treated ◽

Betula Platyphylla Suk

Five hardwood species (Schima superba Gardn, kapur( Dryobalanops sp.), ash (Fraxinus mandshurica Rupr.), birch(Betula platyphylla Suk.), tauari (Couratari sp.)) were conducted the Heat treatment at 185°C.. The results indicated that the dimensional stability, modulus of elasticity (MOE) increased greatly while the wettability decreased after treatment. There was a negative impact of heat treatment on MORs.

Download Full-text

Selected Physical and Mechanical Properties of Microwave Heat Treated Rubberwood (Hevea brasiliensis)

Applied Sciences ◽

10.3390/app10186273 ◽

2020 ◽

Vol 10 (18) ◽

pp. 6273

Author(s):

Aujchariya Chotikhun ◽

Jitralada Kittijaruwattana ◽

Emilia-Adela Salca ◽

Salim Hiziroglu

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Electron Microscope ◽

Dimensional Stability ◽

Hevea Brasiliensis ◽

Physical And Mechanical Properties ◽

Modulus Of Rupture ◽

Heat Treated ◽

Temperature Levels ◽

Microwave Heat

The objectives of this study were to evaluate some of physical and mechanical properties of rubberwood (Hevea brasiliensis) as function of microwave heat treatment process. The specimens were heat treated at three temperature levels of 150 °C, 180 °C, and 220 °C for 20 min in a small microwave oven connected to a computer. Bending characteristics, namely modulus of elasticity (MOE), modulus of rupture (MOR) as well as hardness of the samples were tested. Dimensional stability in the form of swelling and water absorption of the specimens were also determined. Based on the findings in this work it appears that microwave can be used successfully for heat treatment of rubberwood. Overall mechanical properties of the samples were adversely influenced by the treatment. MOE, MOR and hardness values of the samples treated at a temperature of 220 °C had 2.37, 3.69, and 2.12 times reduced than those of control samples, respectively. Dimensional stability of the heat treated samples as a result of 2-h and 24-h water soaking improved. Micrographs take from scanning electron microscope (SEM) and transmission electron microscope (TEM) revealed that certain amount of damage took place in the cellwall of the treated specimens. Overall discoloration on the samples due to microwave heat treatment was found insignificant.

Download Full-text

Hardness and Dimensional Stability of Radiata Pine (Pinus radiata D.Don) Heat-Compressed Wood - Effect of Press Temperature & Time -

Journal of the Korean Wood Science and Technology ◽

10.5658/wood.2011.39.3.206 ◽

2011 ◽

Vol 39 (3) ◽

pp. 206-212 ◽

Cited By ~ 5

Author(s):

Sung-Wook Hwang ◽

Won-Hee Lee

Keyword(s):

Pinus Radiata ◽

Dimensional Stability ◽

Radiata Pine ◽

Press Temperature ◽

Compressed Wood ◽

Temperature Time

Download Full-text

Influence of blue stain on density and dimensional stability of Pinus radiata timber from northern Galicia (Spain)

Holzforschung ◽

10.1515/hf-2014-0014 ◽

2015 ◽

Vol 69 (1) ◽

pp. 97-102 ◽

Cited By ~ 7

Author(s):

María C. Abuín Rouco ◽

Guillermo Riesco Muñoz

Keyword(s):

Physical Properties ◽

Pinus Radiata ◽

Dimensional Stability ◽

Basic Density ◽

Ring Width ◽

Axial Direction ◽

Volumetric Shrinkage ◽

Cambial Age ◽

Pine Trees ◽

Blue Stain

Abstract The presence of blue-stain fungi considerably decreases the value of Pinus radiata timber, which is commercially important in Galicia (NW Spain). For this study, seven young pine trees growing in four different plantations were felled, and 20 discs were sampled from different heights in the stems. Parts of the discs were discoloured as a result of fungal infection. The discs were cut into small specimens. Defect-free specimens (controls) were selected for determining density and dimensional stability both in the volume and in the axial direction. Physical properties of fully blue-stained specimens and the controls were compared for each disc based on one-factor analysis of variance. As the factor was blue-stain, the other sources of variation were suppressed, such as tree source, height in the stem, ring width, cambial age and presence of heartwood or sapwood. Most of the physical properties analysed on some sample discs differed significantly between discoloured and unstained wood. The variables most affected by blue stain were basic density and volumetric shrinkage: blue-stained wood was 1.1% lighter and volumetric shrinkage was 5% higher in blue-stained wood than in the controls.

Download Full-text