Densified Radiata Pine for Structural Composites

Kamke, Frederick A.

doi:10.4067/s0718-221x2006000200002

Cited by 82 publications

(66 citation statements)

References 10 publications

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“…Gao et al (2016) employed a sandwich compression of wood with 6 MPa pressure, which is far less than the lowest pressure level (50 MPa) used in this study. Another distinct advantage of using HP compaction as used in this study is the relatively short processing time (5 min) as compared with long compaction processing times (0.5 to 5 h) in traditional methods (Morsing 2000;Kamke 2006;Kutnar and Kamke 2012;Gao et al 2016;Laine et al 2016). Furthermore, in most traditional methods, the process requires long treatment times at elevated temperatures (mostly above 150 °C) which indicates that the HP compression of wood for densification not only saves time but also saves energy (no need for heating during processing).…”

Section: Densificationmentioning

confidence: 99%

High-Pressure Treatment of Chinese Fir Wood: Effect on Density, Mechanical Properties, Humidity-Related Moisture Migration, and Dimensional Stability

Li¹,

Zhang²,

Ramaswamy³

et al. 2016

BioResources

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A new densification technique for industrial uses of plantation wood was studied. Chinese fir wood was treated by high pressure (HP) at 50 to 200 MPa for 5 min. The density and mechanical properties, moisture sorption isotherm (MSI), and dimensional changes of the pressure-treated wood under various relative humidity (RH) storage conditions were evaluated. The densities of HP-treated wood ranged from 0.79 ± 0.01 g/cm 3 after treatment at 50 MPa to 0.92 ± 0.02 g/cm 3 at 200 MPa, which was significantly higher (p < 0.05) than that of the control (0.35 ± 0.01 g/cm 3 ). Hardness values in radial and tangential fiber alignment faces also significantly increased by 370% to 470% and 350% to 460%, respectively, as compared with the control. The modulus of elasticity and the modulus of rupture of pressure-treated wood increased by 48% to 88% and 89% to 170%, respectively. The equilibrium moisture content varied with RH, decreasing slightly at 33% and 52% while significantly increasing (p < 0.001) at 86% and 93% RH. Radial, tangential, and volumetric dimensions of densified wood were relatively stable at 33%, 52%, and 67% RH, while remarkable swelling occurred at 86% and 93% RH.

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Section: Densificationmentioning

confidence: 99%

High-Pressure Treatment of Chinese Fir Wood: Effect on Density, Mechanical Properties, Humidity-Related Moisture Migration, and Dimensional Stability

Li¹,

Zhang²,

Ramaswamy³

et al. 2016

BioResources

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“…Wood densification is one of the most common methods for the modification of mechanical properties. It works with the principle that these properties are directly dependent on changes in wood density and has been confirmed by a number of authors dealing with either surface densification (Lamason and Gong 2007;Gong et al 2010;Rautkari et al 2009Rautkari et al , 2011Laine et al 2013Laine et al , 2014 or volumetric densification (Navi and Girardet 2000;Kamke 2006). The final densification effect also depends on other conditions and their mutual combinations, such as the use of plasticizing, temperature, moisture content, presence of chemical substances, etc.…”

Section: Introductionmentioning

confidence: 79%

Impact Bending Strength and Brinell Hardness of Densified Hardwoods

et al. 2016

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The objective of this research was to determine the influence of wood species (Fagus sylvatica L. and Populus tremula L.), thickness (4, 6, 10, 18 mm), and degree of densification (0%, 10%, and 20%) on the impact bending strength (IBS) and Brinell hardness (BH) in the radial direction. Three-factor analysis of variance confirmed that the difference in IBS was significantly related to the wood species and wood thickness. Wood densification did not have a significant effect on IBS. In addition, beech wood exhibited higher IBS values than aspen wood. The IBS values increased proportionally with increasing thickness. All factors affecting Brinell hardness were statistically significant, although thickness had the smallest influence overall. The Brinell hardness values were substantially higher in beech wood than aspen wood, and in some cases were more than three times greater. On the other hand, densification exhibited a more positive effect on increasing Brinell hardness for aspen wood than beech wood. Keywords INTRODUCTIONWood is generally recognized as one of the most important renewable resources and among the most versatile and widely used materials. On the other hand, much of its uses depend on the species, because while some tree species are used almost everywhere, others have limited application. The application of wood is directly influenced by its physical and mechanical properties.European beech (Fagus sylvatica L.) is a native wood that grows throughout Europe (Eilmann et al. 2014). Beech is one of the most commonly used hardwoods in Europe (Pöhler et al. 2006;Gryc et al. 2008) for furniture, floors, toys, veneer products, and musical instruments, as well as for the production of stairs, cladding, and glued loadbearing elements in construction (Ohnesorge et al. 2010;Aicher and Ohnesorge 2011;Guntekin et al. 2014). On the other hand, European aspen (Populus tremula L.) wood has only occasional uses. In the woodworking industry, aspen is used in the manufacturing of wood-based materials (plywoods, particle, and flakeboards), in the furniture industry for underlying veneers or surface veneers for backside or nonvisible surfaces (Kärki 2001), and for the facings of ceilings or saunas where high strength or hardness are not necessary (Möttönen et al. 2015). In the past, aspen was primarily used for the production of matches; currently, it has application in the production of biomass fuel, paper, and pulp (Kärki 2001; Heräjärvi and Junkkonen 2006). PEER-REVIEWED ARTICLEbioresources.com Gašparík et al. (2016). "IBS and BH of hardwoods," BioResources 11(4), 8638-8652. 8639The uses for these wood species are closely related to their mechanical properties. Mechanical properties differ by wood type because they depend not only on the type of loading (tension, pressure, and bending), but also on the loading's character (static or dynamic loading) (Bal and Bektaş 2012). In general, wood can resist static loading to a greater extent than dynamic loading. Static loading is characterized by an increasing loading forc...

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“…One of the problems in densifications operation is spring back and it can be eliminated thanks to temperature and steam effect [1,5,36]. In densification with chemicals, densified wood material can be obtained as a result of chemical reaction or cooling after fluid natural and artificial resins are absorbed in the gaps of wood material [7,8].…”

Section: Mechanic Wood Modification Methodsmentioning

confidence: 99%

“…Mechanical features of wood material is related mostly to density [3,5,6,8,9]. Since densifying wood material increases its mechanical features and hardness, many trials have been conducted to develop a suitable operation in this matter [3].…”

Section: Introductionmentioning

confidence: 99%