Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.)
The wood is heterogenous material compound from substance of cell walls and air. It is colloidal capillary-cellular material with ortogonal anisotropy (Babiak, 1976). The wood has possibility to bound liquids and gases into the structure. Due to this the wood is hygroskopic material leads to chan...
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doaj-bfbba318ebfa426bb66536e27a3459032020-11-24T22:58:35ZengMendel University PressActa Universitatis Agriculturae et Silviculturae Mendelianae Brunensis1211-85162464-83102010-01-0158110711410.11118/actaun201058010107Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.)Lukáš Merenda0Andrea Nasswettrová1Ústav nauky o dřevě, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republikaÚstav nauky o dřevě, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1, 613 00 Brno, Česká republikaThe wood is heterogenous material compound from substance of cell walls and air. It is colloidal capillary-cellular material with ortogonal anisotropy (Babiak, 1976). The wood has possibility to bound liquids and gases into the structure. Due to this the wood is hygroskopic material leads to changes in dimensions and volume of wood generating at adsorption and desorption of water molecules into the wood. The dimentional changes evoked by changes in moisture content (bounded water) during shrinkage and sweeling have the biggest importance. Shrinkage is making the linear dimensions, area and volume shorter and smaller (Požgaj a kol., 1997). Hygroscopicity and dimensional instability is possible to affect by drying or modification (Horáček, 2004).Wood modification is a process where it causes improvement in material properties. Aimed changes in chemical structure of wood leads to change in material properties. The aim of modification is to reduce negative properties and to improve positive properties. Wood with changed properties has different parameters which it is necessary to investigate.Plasticization as temporary modification of material properties leads to softer wood due to release of intercellular bonds mainly in middle lamela. It makes subsequent processing as areal compression possible (Bouajila et al., 2006). To ther plasticization is necessary to heat up the wood on the certain temperature. The microwave heating is very useful for this heating. It has smaller expenses and time consumption.Pressing or areal compression perpendicular to the gain in radial direction presses the wood and makes it’s density bigger. Areal compression is responsible for changes in submicroscopic, microscopic and makroscopic levels of wood structure. Changes in wood structure leads to changes in linear directions during shrinking.Plasticizated and compressed wood has many of excellent properties, but it has some negative properties too that high temperature treatment reduces.The aim of this article is to find and compare equilibrium mositure content, linear shrinkage in radial, tangential and longitudinal direction of the native spruce wood (Picea abies L. Karst.) with the same values of microwave plasticizated, areal compressed in radial direction perpendicular to the gain and high temperature treated Spruce wood.https://acta.mendelu.cz/58/1/0107/<i>Picea abies</i> (L.) Karst.microwave plasticizationpressing of woodhigh temperature treatmentlinear schrinkageequilibrium moisture content |
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language |
English |
format |
Article |
sources |
DOAJ |
author |
Lukáš Merenda Andrea Nasswettrová |
spellingShingle |
Lukáš Merenda Andrea Nasswettrová Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.) Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis <i>Picea abies</i> (L.) Karst. microwave plasticization pressing of wood high temperature treatment linear schrinkage equilibrium moisture content |
author_facet |
Lukáš Merenda Andrea Nasswettrová |
author_sort |
Lukáš Merenda |
title |
Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.) |
title_short |
Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.) |
title_full |
Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.) |
title_fullStr |
Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.) |
title_full_unstemmed |
Influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of Spruce (Picea abies (L.) Karst.) |
title_sort |
influence of microwave plasticization, areal compression and high-temperature treatment on equilibrum moisture content and shrinkage of spruce (picea abies (l.) karst.) |
publisher |
Mendel University Press |
series |
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis |
issn |
1211-8516 2464-8310 |
publishDate |
2010-01-01 |
description |
The wood is heterogenous material compound from substance of cell walls and air. It is colloidal capillary-cellular material with ortogonal anisotropy (Babiak, 1976). The wood has possibility to bound liquids and gases into the structure. Due to this the wood is hygroskopic material leads to changes in dimensions and volume of wood generating at adsorption and desorption of water molecules into the wood. The dimentional changes evoked by changes in moisture content (bounded water) during shrinkage and sweeling have the biggest importance. Shrinkage is making the linear dimensions, area and volume shorter and smaller (Požgaj a kol., 1997). Hygroscopicity and dimensional instability is possible to affect by drying or modification (Horáček, 2004).Wood modification is a process where it causes improvement in material properties. Aimed changes in chemical structure of wood leads to change in material properties. The aim of modification is to reduce negative properties and to improve positive properties. Wood with changed properties has different parameters which it is necessary to investigate.Plasticization as temporary modification of material properties leads to softer wood due to release of intercellular bonds mainly in middle lamela. It makes subsequent processing as areal compression possible (Bouajila et al., 2006). To ther plasticization is necessary to heat up the wood on the certain temperature. The microwave heating is very useful for this heating. It has smaller expenses and time consumption.Pressing or areal compression perpendicular to the gain in radial direction presses the wood and makes it’s density bigger. Areal compression is responsible for changes in submicroscopic, microscopic and makroscopic levels of wood structure. Changes in wood structure leads to changes in linear directions during shrinking.Plasticizated and compressed wood has many of excellent properties, but it has some negative properties too that high temperature treatment reduces.The aim of this article is to find and compare equilibrium mositure content, linear shrinkage in radial, tangential and longitudinal direction of the native spruce wood (Picea abies L. Karst.) with the same values of microwave plasticizated, areal compressed in radial direction perpendicular to the gain and high temperature treated Spruce wood. |
topic |
<i>Picea abies</i> (L.) Karst. microwave plasticization pressing of wood high temperature treatment linear schrinkage equilibrium moisture content |
url |
https://acta.mendelu.cz/58/1/0107/ |
work_keys_str_mv |
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