Comparison of selected physical and mechanical properties of densified beech wood plasticized by ammonia and saturated steam

Pařil, Petr; Brabec, Martin; Maňák, Ondřej; Rousek, Radim; Rademacher, Peter; Čermák, Petr; Dejmal, Aleš

doi:10.1007/s00107-014-0814-8

Cited by 48 publications

(22 citation statements)

References 15 publications

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“…Although ammonia treatment shows no obvious effect on the content of wood polymers, it can easily access crystal region of cellulose and disrupt the lignin-carbohydrate complex. Moreover, the plasticizing effect of the ammonia treatment is temporary and the deformed wood would be returning back to its initial form and the strong pungent smell after the ammonia treatment limits its industrial application [16,17]. Later, Song et al manufactured the highstrength densified wood by coalescent method which combined NaOH/Na 2 SO 3 solution pretreatment and hot press at 100 °C, exhibiting high specific tensile strength of 422.2 MPa cm 3 g −1 , which is higher than some metals [18].…”

Section: Introductionmentioning

confidence: 99%

Fabrication of densified wood via synergy of chemical pretreatment, hot-pressing and post mechanical fixation

Shi

Peng

Huang³

et al. 2020

J Wood Sci

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Wood densification can improve the strength of low density wood species and extend wood product applications. To enhance the wood compressive quality, chemical pretreatments for pristine wood have widely been used. Densified Abies wood was fabricated by combining NaOH/Na 2 SO 3 solution treatment, hot-pressing and post mechanical fixation. The appearance, color, chemical composition, and physiology and mechanical properties before and after the densification treatment were examined by the colorimeter, FTIR and mechanical testing machine, respectively. Surface color of Abies wood was changed obviously after the densification. The values of brightness L* and b* decreased but the value of a* showed a slight increase in the densified wood. FTIR results confirmed that the color changes can be explained by the degradation of hemicellulose and lignin in wood cell walls and migration of extractives during the densification process. Sufficient removal of wood polymers resulted in the average compression ratio of about 80% in the radial direction of the natural wood. The density of densified wood increased with the wood thickness up to 1.227 g cm −1 , accounting for a 169% increase compared to that of the pristine wood. Modulus of rupture (MOR) and modulus of elasticity (MOE) in the thickness direction of densified wood also markedly enhanced. Degradation of polymers in wood cell walls also was reconfirmed by the difference of fracture interface. All the results suggested that the densified softwood can be easily fabricated using the proposed method and the new densified softwood can be appropriately used as interior decoration materials.

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Section: Introductionmentioning

confidence: 99%

Fabrication of densified wood via synergy of chemical pretreatment, hot-pressing and post mechanical fixation

Shi

Peng

Huang³

et al. 2020

J Wood Sci

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“…Heat treatment at two different temperatures (160 and 200 °C) of Obeche (Triplochiton scleroxylon) wood gave the lower the number of hydroxyl groups and the higher the relative crystallinity index, which would result in improving the dimensional stability and stiffness (Fabiyi andOgunleye 2015, Korkut andAytin 2015). Modification treatment by ammonia and steam of beech densified the wood and enhance its modulus of elasticity and hardness properties as compared to the native beech (Pařil et al 2014). Meanwhile, the resin based modification of maritime pine wood (Pinus pinaster) was enhanced the behaviour on wet conditions improved up to 60% (Lopes et al 2015).…”

Section: Introductionmentioning

confidence: 99%

Physical and mechanical properties of juvenile wood from Neolamarckia cadamba planted in west Malaysia

Mahmud

Hashim

Saleh

et al. 2017

Maderas, Cienc. tecnol.

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Juvenile Neolamarckia cadamba or kelempayan tree has been harvested from forest plantation and converted into sawn timber. Some basic properties of timber such as physical and mechanical were determined from different parts of the tree namely lower, center and upper. The physical properties were evaluated. The mechanical properties were conducted using small test clear specimens. The results indicated that the physical and mechanical properties of the lower portion of the trunk were significantly superior compared to the upper portion of the trunk. The investigation revealed that the wood be able to use as a substitute material of the furniture components after some modification undertaken on its properties.

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“…According to Pařil et al 2013, the values of swelling and shrinkage of solid Lignamon samples are 50% less compared to natural beech. The surface of bathroom furniture will be covered by ammonified veneer, which will protect the core of the furniture and will also be more resistant to humidity in the bathroom thanks to the improved swelling and shrinkage behaviour of Lignamon.…”

Section: Discussionmentioning

confidence: 99%

Plasticity increase of beech veneer by steaming and gaseous ammonia treatment

Šprdlík

Brabec

Mihailović

et al. 2016

Maderas, Cienc. tecnol.

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Ammonia treatment was used in order to change the colour of wood and also to plasticize the wood before bending or compressing. The mechanism and the process of gaseous ammonia treatment impact on wood are not very well known. The goal of this study was to quantify the effect of gaseous ammonia on mechanical properties, i.e., modulus of elasticity (MOE), modulus of rupture (MOR) and deflection at maximal loading force (y Fmax ). When wood was treated by water and ammonia vapour together, significant changes in plasticity of wood were observed. The samples which were firstly exposed to water vapour and then to ammonia vapour exhibit the lowest values of MOE and MOR and an enhanced flexibility of the material. The results show that ammonia treatment increases wood plasticity. This process can be used for manufacturing of bent furniture.

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Comparison of selected physical and mechanical properties of densified beech wood plasticized by ammonia and saturated steam

Cited by 48 publications

References 15 publications

Fabrication of densified wood via synergy of chemical pretreatment, hot-pressing and post mechanical fixation

Fabrication of densified wood via synergy of chemical pretreatment, hot-pressing and post mechanical fixation

Physical and mechanical properties of juvenile wood from Neolamarckia cadamba planted in west Malaysia

Plasticity increase of beech veneer by steaming and gaseous ammonia treatment

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