Contact angle as function of surface roughness of different wood species

Papp, Eva Annamaria; Csiha, Csilla

doi:10.1016/j.surfin.2017.04.009

Cited by 46 publications

(35 citation statements)

References 16 publications

(17 reference statements)

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“…The contact angle mean value 100 ± 9º of birch wood veneers was the highest among the investigated three kinds of un-treated wood species and exceeded 90º that indicates the hydrophobicity of material itself. It means that there is low surface wettability, Papp [16] points out that un-treated birch (Betulapendula Roth.) contact angle is 72º.…”

Section: Resultsmentioning

confidence: 99%

Thermal modification as tool to increase hydrophobicity of veneers

Meija-Feldmane

Sansonetti

Morozovs

et al. 2019

Engineering for Rural Development

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Plywood is a well-known material with versatile usage due to its strength to weight ratio. One of the drawbacks of this material is its susceptibility to wood colouring and degradation by the influence of fungi. Fungal growth is directly related to the wood service conditions, among which moisture is the most important. One of the ways of reducing the wood moisture content by the increase of the hydrophobicity of the material is a thermal modification (TM). Thermowood® is the most popular among many thermal treatment technologies. In this paper two less common TM methodologies-WTT and TERMOVUOTO® were used. The WTT technology is a closed process, where the thermal modification is conducted in water vapour environment with elevated pressure of about 7 bar, whereas the TERMOVUOTO® process is an open process with reduced pressure 0.25 bar. Three low-density wood species veneers were investigated-aspen (Populustremula L.), poplar (Populus x canadensisMoench) and birch (Betulapendula Roth). Aspen and birch veneers were treated according to WTT technology under previously determined optimal regime 160 ºC/50 min and it was used as a reference. Poplar and birch veneers were treated according to the TERMOVUOTO® technology with four experimental regimes 204 ºC/2 h, 214 ºC/2 h, 217 ºC/3 h, 218 ºC/30 min. The comparison of the contact angle values of untreated , thermo-vacuum treated and hydro-thermal treated birch and poplar wood veneer surface was used to evaluate the thermal treatment method effect. The treatment process smoothed the hydrophobic properties of the treated veneer surfaces regardless of the process severity and hardwood species peculiarities. The obtained results make it easier to deal with the gluing process of thermally modified veneers, allowing not to consider the impact of the treatment regime.

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Section: Resultsmentioning

confidence: 99%

Thermal modification as tool to increase hydrophobicity of veneers

Meija-Feldmane

Sansonetti

Morozovs

et al. 2019

Engineering for Rural Development

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“…The decrease in wettability of untreated specimens after AWT can be attributed to the increasing in the surface roughness of wood due to swelling and shrinkage, and to the migration of non-polar extractives induced by AWT [37,38]. On the opposite, AWT determined an increase of wettability of thermo-treated specimens.…”

Section: Discussionmentioning

confidence: 99%

Physico-Mechanical Properties of Thermally Treated Poplar OSB

Cetera

Negro

Cremonini

et al. 2018

Forests

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Abstract:Oriented strand board (OSB) are widely marketed for several applications, from building to packaging. The manufacturing of poplar OSB has recently started in Northern Italy, representing a relevant innovation in the sector, given that this product is usually made of coniferous wood. Thermal treatment is nowadays widely used for increasing the dimensional stability and the durability of wood. The drawback is, however, that the mechanical performance of the treated wood product is reduced. The objective of this research was to analyze the effect of thermo-vacuum treatment on the characteristics of poplar OSB. To this purpose, boards 15 mm thick and with a density of 590 kg/m 3 were drawn from the standard production of the manufacturer and thermally treated under vacuum conditions at 190 • C for 2 h. Their mass loss, bending strength, modulus of elasticity, internal bond and swelling were determined. In addition, color change and wettability were studied before and after a weathering test. The thermal treatment significantly changed the properties of poplar OSB. The mass, the bending strength, the modulus of elasticity and the internal bond decreased with different intensities. The swelling after immersion in water decreased. The color switched toward a darker tone and the wettability decreased. After an accelerated weathering test (AWT), the color lightened, and the wettability increased. Overall, this study broadened the knowledge about the thermal treatment of this wood-based panel, which could enable new applications with particular attention to non-structural uses in humid conditions.

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“…Existem outras formas para se realizar essa medição com baixo custo, que utiliza câmera digital, plataforma para o substrato, softwares de fácil acesso (STALDER et al, 2006) e iluminação apropriada, além de uma seringa de precisão, que apresentam resultados aceitáveis e próximos aos equipamentos especializados (THAKKER et al, 2013;STALDER et al, 2006 onde , e representam as tensões de líquido-vapor, sólido-vapor e sólido-líquido, respectivamente, e é o ângulo de contato A equação (1) é chamada de Equação de Young (DE GENNES, 1985;YUAN;LEE, 2013). No caso do método da gota séssil, é preferível que a gota possua pequeno volume para que a influência da gravidade seja mínima, dessa forma a gota tende a assumir formato esférico (THAKKER et al, 2013;DE GENNES, 1985 (NUSSBAUM, 1995;NUSSBAUM, 1999;PAPP;CSIHA, 2017;SHUPE et al, 2001). Hse (1972)…”

Section: Introductionunclassified

Ângulo de Contato e Rugosidade de Madeiras, uma breve revisão

Sinderski

2020

RCM

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RESUMO Essa revisão discute a molhabilidade de superfícies de madeira através do ângulo de contato, que por sua vez qualifica a molhabilidade e pode fornecer a energia livre, ou tensão da superfície. Discute-se o método da gota séssil por sua simplicidade e relativa precisão para aferir o ângulo de contato. Mesmo que a madeira é caracterizada como um material altamente anisotrópico e heterogêneo é possível verificar o ângulo de contato e assimilar o resultado com outras variáveis da superfície da madeira, como quantidade de extrativos e lignina, a rugosidade superficial e o tipo de lenho da madeira. Tratamentos comuns à madeira também influenciam no ângulo de contato e molhabilidade, pois existe relação evidente entre o lixamento da madeira e a rugosidade assim como os efeitos que que o lixamento causa no ângulo de contato. Palavras-chave: madeira; molhabilidade; ângulo de contato; rugosidade. Contact angle and roughness of wood, a short review ABSTRACT This review discusses the wettability of wood surfaces through the contact angle, which in turn qualifies the wettability and can provide free energy, or surface tension. The sessile drop method is discussed for its simplicity and relative accuracy to measure the contact angle. Although the wood is characterized as a highly anisotropic and heterogeneous material, it is possible to verify the contact angle and to assimilate the result with other variables of the wood surface, such as the amount of extractives and lignin, the surface roughness and type of the wood, earlywood or latewood. Treatments common to wood also influence the contact angle and its wettability, since there is a clear relationship between the sanding and the roughness as well as the effects that sanding causes on the contact angle.

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Contact angle as function of surface roughness of different wood species

Cited by 46 publications

References 16 publications

Thermal modification as tool to increase hydrophobicity of veneers

Thermal modification as tool to increase hydrophobicity of veneers

Physico-Mechanical Properties of Thermally Treated Poplar OSB

Ângulo de Contato e Rugosidade de Madeiras, uma breve revisão

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