Physical-mechanical alterations in Qualea paraensis wood after heat treatment
The objective was to analyze the effect of heat treatments on the physical and mechanical properties of Qualea paraensis wood. Test specimens from 5 lots of wood were submitted to heat treatments using temperatures of 180 °C and 200 °C with periods of 2 h and 4 h. Density (ρa), mass loss (PM), equil...
| Príomhchruthaitheoirí: | , , , , |
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| Formáid: | Online |
| Teanga: | spa |
| Foilsithe / Cruthaithe: |
Instituto de Ecología, A.C.
2021
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| Rochtain ar líne: | https://myb.ojs.inecol.mx/index.php/myb/article/view/2176 |
| _version_ | 1799769416192229376 |
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| author | Medeiros, Dayane Targino de Batista, Felipe Gomes Melo, Rafael Rodolfo de Mascarenhas, Adriano Reis Prazeres Pedrosa, Talita Dantas |
| author_facet | Medeiros, Dayane Targino de Batista, Felipe Gomes Melo, Rafael Rodolfo de Mascarenhas, Adriano Reis Prazeres Pedrosa, Talita Dantas |
| author_sort | Medeiros, Dayane Targino de |
| collection | MYB |
| description | The objective was to analyze the effect of heat treatments on the physical and mechanical properties of Qualea paraensis wood. Test specimens from 5 lots of wood were submitted to heat treatments using temperatures of 180 °C and 200 °C with periods of 2 h and 4 h. Density (ρa), mass loss (PM), equilibrium moisture content (UE), longitudinal (βl), radial (βr) and tangential (βt) shrinkage, volumetric shrinkage (βv) and anisotropic factor (fa) were determined. Mechanically, the wood was evaluated for strength and stiffness in the tests of static bending (fM and EM) and compression parallel to the fibers (fc0 and Ec0). After the heat treatments, the values of ρ12% increased, on average, by 7.72% and the UE was reduced by 24.3%. The highest values of PM (3.67%) were observed for the exposure time of 2 hours at a temperature of 200 °C. With this treatment, the lowest values of βt (5.73%) and βv (9.69%) were obtained. The thermal treatments increased the bulk density, reduced the equilibrium moisture content, and increased the dimensional stability of the wood. In most heat treatments, a reduction in strength and an increase in stiffness to static bending was observed. There was an increase in strength and stiffness to compression parallel to the grain in all combinations of time and temperature. The greatest dimensional stability with less loss of strength to static bending and parallel compression were obtained with the treatment at 200 °C and time of 2 h. |
| format | Online |
| id | oai:oai.myb.ojs.inecol.mx:article-2176 |
| institution | Madera y Bosques |
| language | spa |
| publishDate | 2021 |
| publisher | Instituto de Ecología, A.C. |
| record_format | ojs |
| spelling | oai:oai.myb.ojs.inecol.mx:article-21762022-11-29T22:24:23Z Physical-mechanical alterations in Qualea paraensis wood after heat treatment Alterações físico-mecânicas na madeira de cambará (Qualea paraensis) termorretificada Medeiros, Dayane Targino de Batista, Felipe Gomes Melo, Rafael Rodolfo de Mascarenhas, Adriano Reis Prazeres Pedrosa, Talita Dantas wood density tropical wood mass loss modulus of rupture heat treatment densidade da madeira madeira tropical perda de massa módulo de ruptura tratamento térmico The objective was to analyze the effect of heat treatments on the physical and mechanical properties of Qualea paraensis wood. Test specimens from 5 lots of wood were submitted to heat treatments using temperatures of 180 °C and 200 °C with periods of 2 h and 4 h. Density (ρa), mass loss (PM), equilibrium moisture content (UE), longitudinal (βl), radial (βr) and tangential (βt) shrinkage, volumetric shrinkage (βv) and anisotropic factor (fa) were determined. Mechanically, the wood was evaluated for strength and stiffness in the tests of static bending (fM and EM) and compression parallel to the fibers (fc0 and Ec0). After the heat treatments, the values of ρ12% increased, on average, by 7.72% and the UE was reduced by 24.3%. The highest values of PM (3.67%) were observed for the exposure time of 2 hours at a temperature of 200 °C. With this treatment, the lowest values of βt (5.73%) and βv (9.69%) were obtained. The thermal treatments increased the bulk density, reduced the equilibrium moisture content, and increased the dimensional stability of the wood. In most heat treatments, a reduction in strength and an increase in stiffness to static bending was observed. There was an increase in strength and stiffness to compression parallel to the grain in all combinations of time and temperature. The greatest dimensional stability with less loss of strength to static bending and parallel compression were obtained with the treatment at 200 °C and time of 2 h. Objetivou-se analisar o efeito do tempo e da temperatura de tratamentos térmicos nas propriedades físico-mecânicas da madeira de cambará (Qualea paraensis Ducke). Foram confeccionados corpos de prova de 5 lotes da madeira de cambará submetidos ao tratamento térmico em estufa sob temperaturas de 180 °C e 200 °C e períodos de 2 h e 4 h. Determinou-se densidade aparente (ρ12%), perda de massa (PM), umidade de equilíbrio (UE), contrações nos eixos longitudinal (βl), radial (βr) e tangencial (βt), contração volumétrica (βv) e fator anisotrópico (fa). Mecanicamente, a madeira foi avaliada quanto à resistência e rigidez nos ensaios de flexão estática (fM e EM) e compressão paralela às fibras (fc0 e Ec0). Após os tratamentos térmicos, os valores de ρ12% aumentaram, em média, 7,72% e a UE foi reduzida em 24,3%. Os maiores valores de PM (3,67%) foram observados para o tempo de exposição de 2 h em temperatura de 200 °C. Com este tratamento, obteve-se também os menores valores de βt (5,73%) e βv (9,69%). Os tratamentos térmicos aumentaram a densidade aparente, reduziram a umidade de equilíbrio e aumentaram a estabilidade dimensional da madeira. Na maioria dos tratamentos térmicos, observou-se redução da resistência e aumento da rigidez à flexão estática. Ocorreu aumento da resistência e da rigidez à compressão paralela à grã em todas as combinações de tempo e temperatura. De modo geral, a maior estabilidade dimensional com menores perdas da resistência à flexão estática e compressão paralela foram obtidas com o tratamento de 200 °C e tempo de 2 h. Instituto de Ecología, A.C. 2021-12-22 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Artículo evaluado por pares text/xml application/pdf https://myb.ojs.inecol.mx/index.php/myb/article/view/2176 10.21829/myb.2021.2722176 Madera y Bosques; Vol. 27 No. 2 (2021): Summer 2021; e2722176 Madera y Bosques; Vol. 27 Núm. 2 (2021): Verano 2021; e2722176 2448-7597 1405-0471 spa https://myb.ojs.inecol.mx/index.php/myb/article/view/2176/2342 https://myb.ojs.inecol.mx/index.php/myb/article/view/2176/2291 10.21829/myb.2018.243610 10.21829/myb.2019.252482 Derechos de autor 2021 Madera y Bosques http://creativecommons.org/licenses/by-nc-sa/4.0 |
| spellingShingle | Medeiros, Dayane Targino de Batista, Felipe Gomes Melo, Rafael Rodolfo de Mascarenhas, Adriano Reis Prazeres Pedrosa, Talita Dantas Physical-mechanical alterations in Qualea paraensis wood after heat treatment |
| title | Physical-mechanical alterations in Qualea paraensis wood after heat treatment |
| title_full | Physical-mechanical alterations in Qualea paraensis wood after heat treatment |
| title_fullStr | Physical-mechanical alterations in Qualea paraensis wood after heat treatment |
| title_full_unstemmed | Physical-mechanical alterations in Qualea paraensis wood after heat treatment |
| title_short | Physical-mechanical alterations in Qualea paraensis wood after heat treatment |
| title_sort | physical-mechanical alterations in qualea paraensis wood after heat treatment |
| url | https://myb.ojs.inecol.mx/index.php/myb/article/view/2176 |
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