Evelize Aparecida Amaral, Lívia Freire Baliza, Luana Maria dos Santos, André Tetsuo Shashiki, P. F. Trugilho, P. R. Hein
Abstract The physical properties of wood are important parameters to qualify the material. However, as it is a heterogeneous material, moisture content and wood contractions may vary within the sample. Thus, the objective was to monitor the hydromechanical behavior of wood during drying using near infrared (NIR) spectroscopy and image analysis. Equidistant points were marked on the radial surface of a wooden board and NIR spectra were recorded at each marking during drying of the piece. After spectral acquisition in each drying step, images were obtained and the markings were referenced to monitor contractions during drying. Moisture content (MC) estimates via NIR spectra showed strong correlation with reference values (R2cv = 0.92, RMSEcv = 9.82 %). From the estimates it was possible to generate graphic images to visualize and quantify the spatial variation of MC and shrinkage during wood drying. In the initial stages of drying, the ends of the material showed high moisture in relation to the center of the sample. However, MC loss was 11 % greater at the ends of the wood board when compared to its interior while the shrinkage in external zones was 3 times greater than the internal part. The use of NIR technique associated with image analysis can be a promising tool for estimating moisture contents and contractions in wood.
{"title":"Hydromechanical behavior of wood during drying studied by NIR spectroscopy and image analysis","authors":"Evelize Aparecida Amaral, Lívia Freire Baliza, Luana Maria dos Santos, André Tetsuo Shashiki, P. F. Trugilho, P. R. Hein","doi":"10.1515/hf-2023-0030","DOIUrl":"https://doi.org/10.1515/hf-2023-0030","url":null,"abstract":"Abstract The physical properties of wood are important parameters to qualify the material. However, as it is a heterogeneous material, moisture content and wood contractions may vary within the sample. Thus, the objective was to monitor the hydromechanical behavior of wood during drying using near infrared (NIR) spectroscopy and image analysis. Equidistant points were marked on the radial surface of a wooden board and NIR spectra were recorded at each marking during drying of the piece. After spectral acquisition in each drying step, images were obtained and the markings were referenced to monitor contractions during drying. Moisture content (MC) estimates via NIR spectra showed strong correlation with reference values (R2cv = 0.92, RMSEcv = 9.82 %). From the estimates it was possible to generate graphic images to visualize and quantify the spatial variation of MC and shrinkage during wood drying. In the initial stages of drying, the ends of the material showed high moisture in relation to the center of the sample. However, MC loss was 11 % greater at the ends of the wood board when compared to its interior while the shrinkage in external zones was 3 times greater than the internal part. The use of NIR technique associated with image analysis can be a promising tool for estimating moisture contents and contractions in wood.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47970197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Bengtsson, Andreas Bengtsson, Hanna Ulmefors, Maria Sedin, Kerstin Jedvert
Abstract Adhesion of fibers within a spun tow, including carbon fibers and precursors, is undesirable as it may interrupt the manufacturing process and entail inferior fiber properties. In this work, softwood kraft lignin was used together with a dissolving pulp to spin carbon fiber precursors. Lignin–cellulose precursors have previously been found to be prone to fiber fusion, both post-spinning and during carbon fiber conversion. In this study, the efficiency of applying different kinds of spin finishes, with respect to rendering separable precursors and carbon fibers, has been investigated. It was found that applying a cationic surfactant, and to a similar extent a nonionic surfactant, resulted in well separated lignin–cellulose precursor tows. Furthermore, the fiber separability after carbon fiber conversion was evaluated, and notably, precursors treated with a silicone-based spin finish generated the most well-separated carbon fibers. The underlying mechanism of fiber fusion post-spinning and converted carbon fibers is discussed.
{"title":"Preventing fiber–fiber adhesion of lignin–cellulose precursors and carbon fibers with spin finish application","authors":"J. Bengtsson, Andreas Bengtsson, Hanna Ulmefors, Maria Sedin, Kerstin Jedvert","doi":"10.1515/hf-2023-0023","DOIUrl":"https://doi.org/10.1515/hf-2023-0023","url":null,"abstract":"Abstract Adhesion of fibers within a spun tow, including carbon fibers and precursors, is undesirable as it may interrupt the manufacturing process and entail inferior fiber properties. In this work, softwood kraft lignin was used together with a dissolving pulp to spin carbon fiber precursors. Lignin–cellulose precursors have previously been found to be prone to fiber fusion, both post-spinning and during carbon fiber conversion. In this study, the efficiency of applying different kinds of spin finishes, with respect to rendering separable precursors and carbon fibers, has been investigated. It was found that applying a cationic surfactant, and to a similar extent a nonionic surfactant, resulted in well separated lignin–cellulose precursor tows. Furthermore, the fiber separability after carbon fiber conversion was evaluated, and notably, precursors treated with a silicone-based spin finish generated the most well-separated carbon fibers. The underlying mechanism of fiber fusion post-spinning and converted carbon fibers is discussed.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42513619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract To elucidate the mechanism of wood sandwich compression, the response of wood compressing yield stress to hygrothermal conditions was investigated in this study with respect to preheating temperature (30–210 °C) and moisture content (MC, 0–100 %). An associated functional model was developed to predict wood yield stress based on the measured MC and temperature in wood. A 1 % increase in wood MC or a 10 °C increase of temperature led to a decrease in wood yield stress exceeding 0.1 MPa. Significant variations in yield stress, exceeding 0.8 MPa, were observed between high MC layer(s) and the remaining layer(s) along the wood thickness when there was an MC variation over 5 %. Preheating the wood with by heating platens accelerated water/moisture migration in wood, resulting in relatively low yield stress in the wood interior areas where water/moisture had migrated. This study demonstrated that the comparatively low yield stress of some wood areas was responsible for sandwich compression. When mechanically compressed, only the wood layer(s) with lower yield stress was compressed, leading to sandwich compression, regardless of whether the mechanical force was applied tangentially or radially.
{"title":"Mechanism elucidation for wood sandwich compression from the perspective of yield stress","authors":"Rongfeng Huang, S. Feng, Zhiqiang Gao, H. Liu","doi":"10.1515/hf-2023-0002","DOIUrl":"https://doi.org/10.1515/hf-2023-0002","url":null,"abstract":"Abstract To elucidate the mechanism of wood sandwich compression, the response of wood compressing yield stress to hygrothermal conditions was investigated in this study with respect to preheating temperature (30–210 °C) and moisture content (MC, 0–100 %). An associated functional model was developed to predict wood yield stress based on the measured MC and temperature in wood. A 1 % increase in wood MC or a 10 °C increase of temperature led to a decrease in wood yield stress exceeding 0.1 MPa. Significant variations in yield stress, exceeding 0.8 MPa, were observed between high MC layer(s) and the remaining layer(s) along the wood thickness when there was an MC variation over 5 %. Preheating the wood with by heating platens accelerated water/moisture migration in wood, resulting in relatively low yield stress in the wood interior areas where water/moisture had migrated. This study demonstrated that the comparatively low yield stress of some wood areas was responsible for sandwich compression. When mechanically compressed, only the wood layer(s) with lower yield stress was compressed, leading to sandwich compression, regardless of whether the mechanical force was applied tangentially or radially.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47581842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Vaziri, Christopher H. Dreimol, Lars Abrahamsson, P. Niemz, D. Sandberg
Abstract The single exponential kinetics (SEK) and parallel exponential kinetics (PEK) models were fitted to kinetic sorption data of welded and unwelded Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.). Furthermore, diffusion coefficients of water vapour in wood were determined using two different Fickian diffusion solutions. The objective was to identify how well these models could represent the moisture contents of the specimens and to characterize differences between the sorption behaviour of welded and unwelded wood. This knowledge can be used to enhance the moisture resistance of welded wood, develop drying schedules, and improve the quality of timbers. The PEK and SEK models provided the most precise and the second most precise fits to the sorption kinetic data, respectively. The two Fickian models are equivalent when both the infinite series are truncated at n = 10 $n=10$ . The Fickian models also exhibited the highest discrepancy with the experimental data. Nevertheless, the Fickian models fit relatively better to the sorption data of the welded wood than to that of the unwelded wood. This behaviour may be due to the rigid and less-swelling structure of the welded bond line.
{"title":"Parameter estimation and model selection for water vapour sorption of welded bond-line of European beech and Scots pine","authors":"M. Vaziri, Christopher H. Dreimol, Lars Abrahamsson, P. Niemz, D. Sandberg","doi":"10.1515/hf-2022-0013","DOIUrl":"https://doi.org/10.1515/hf-2022-0013","url":null,"abstract":"Abstract The single exponential kinetics (SEK) and parallel exponential kinetics (PEK) models were fitted to kinetic sorption data of welded and unwelded Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.). Furthermore, diffusion coefficients of water vapour in wood were determined using two different Fickian diffusion solutions. The objective was to identify how well these models could represent the moisture contents of the specimens and to characterize differences between the sorption behaviour of welded and unwelded wood. This knowledge can be used to enhance the moisture resistance of welded wood, develop drying schedules, and improve the quality of timbers. The PEK and SEK models provided the most precise and the second most precise fits to the sorption kinetic data, respectively. The two Fickian models are equivalent when both the infinite series are truncated at n = 10 $n=10$ . The Fickian models also exhibited the highest discrepancy with the experimental data. Nevertheless, the Fickian models fit relatively better to the sorption data of the welded wood than to that of the unwelded wood. This behaviour may be due to the rigid and less-swelling structure of the welded bond line.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41767043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tom Franke, Christina Hinterleitner, A. Maillard, Elena Nedelkoska, T. Volkmer
Abstract A treatment to improve the reaction to fire of wood is the wood mineralization. Besides the reaction to fire of the mineralized wood, other mechanical and physical properties are less investigated. In this study, beech and oak were treated in a 2-step mineralization process to obtain calcium oxalate mineralized wood. The 2-step mineralization process is carried out by impregnating two salts diluted in water into the wood, consecutively. Two formulations were applied. For Formulation 1, potassium oxalate and calcium acetate and for Formulation 2 potassium oxalate and calcium chloride were used. Aim of the study is to investigate the impact of the treatments and in combination of the moisture on some selected properties of the mineralized wood. These properties are the swelling due to the mineralization treatment, the Brinell hardness and the volatile organic compounds emissions. The 2-step mineralization treatments increased the moisture adsorption of wood. However, the removal of unreacted precursors due to leaching provides a material with comparable moisture dynamics to untreated wood. Swelling, hardness and volatile organic compounds emissions are decreased by the mineralization. However, leaching of the reaction by-products leads to a material with comparable properties to those of untreated wood.
{"title":"The impact of moisture on salt treated and 2-step mineralized wood","authors":"Tom Franke, Christina Hinterleitner, A. Maillard, Elena Nedelkoska, T. Volkmer","doi":"10.1515/hf-2023-0003","DOIUrl":"https://doi.org/10.1515/hf-2023-0003","url":null,"abstract":"Abstract A treatment to improve the reaction to fire of wood is the wood mineralization. Besides the reaction to fire of the mineralized wood, other mechanical and physical properties are less investigated. In this study, beech and oak were treated in a 2-step mineralization process to obtain calcium oxalate mineralized wood. The 2-step mineralization process is carried out by impregnating two salts diluted in water into the wood, consecutively. Two formulations were applied. For Formulation 1, potassium oxalate and calcium acetate and for Formulation 2 potassium oxalate and calcium chloride were used. Aim of the study is to investigate the impact of the treatments and in combination of the moisture on some selected properties of the mineralized wood. These properties are the swelling due to the mineralization treatment, the Brinell hardness and the volatile organic compounds emissions. The 2-step mineralization treatments increased the moisture adsorption of wood. However, the removal of unreacted precursors due to leaching provides a material with comparable moisture dynamics to untreated wood. Swelling, hardness and volatile organic compounds emissions are decreased by the mineralization. However, leaching of the reaction by-products leads to a material with comparable properties to those of untreated wood.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41353638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Tree bark is normally a side-stream product but by an integrated bark biorefinery approach, valuable compounds may be recovered and used to replace fossil-based products. Norway spruce bark was extracted to obtain cellulose, which was chemically treated to produce cellulose oxalate (COX) which was homogenized to yield nanocellulose. The nanocellulose was used to produce Pickering emulsions with almond oil and hexadecane as organic phases. COX from dissolving pulp was used to study the effect of various raw materials on the emulsifying properties. The COX samples of bark and dissolving pulp contained a significant amount of hemicelluloses, which affected the viscosity results. The emulsion properties were affected by the organic phases and the aspect ratio. Emulsions using hexadecane were more stable than the emulsions using almond oil. Since the aspect ratio of bark was lower than that of the dissolving pulp, the emulsifying properties of the COX dissolving pulp was better. It has been shown that nanocellulose from cellulose oxalate of both spruce bark and dissolving pulp is a promising substitute for petroleum-based emulsifiers and surfactants. By utilizing bark, value-added products can be produced which may be economically beneficial for various industries in the future and their aim for climate-neutral products.
{"title":"Emulsions of cellulose oxalate from Norway spruce (Picea abies) bark and dissolving pulp","authors":"Isabella Kwan, B. Rietzler, M. Ek","doi":"10.1515/hf-2022-0191","DOIUrl":"https://doi.org/10.1515/hf-2022-0191","url":null,"abstract":"Abstract Tree bark is normally a side-stream product but by an integrated bark biorefinery approach, valuable compounds may be recovered and used to replace fossil-based products. Norway spruce bark was extracted to obtain cellulose, which was chemically treated to produce cellulose oxalate (COX) which was homogenized to yield nanocellulose. The nanocellulose was used to produce Pickering emulsions with almond oil and hexadecane as organic phases. COX from dissolving pulp was used to study the effect of various raw materials on the emulsifying properties. The COX samples of bark and dissolving pulp contained a significant amount of hemicelluloses, which affected the viscosity results. The emulsion properties were affected by the organic phases and the aspect ratio. Emulsions using hexadecane were more stable than the emulsions using almond oil. Since the aspect ratio of bark was lower than that of the dissolving pulp, the emulsifying properties of the COX dissolving pulp was better. It has been shown that nanocellulose from cellulose oxalate of both spruce bark and dissolving pulp is a promising substitute for petroleum-based emulsifiers and surfactants. By utilizing bark, value-added products can be produced which may be economically beneficial for various industries in the future and their aim for climate-neutral products.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46131446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Yan, Zeyao Yan, Jiang Chen, Zhang-jing Chen, Yafang Lei
Abstract Vanillin is an antifungal and environmentally friendly compound. In this study, vanillin and silica microcapsules (VSM) were microencapsulated using the sol-gel method and then impregnated into wood. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDXA) and transmission electron microscopy (TEM) were used to characterize the morphological structure and distribution of VSM in wood. Fourier transform infrared spectroscopy (FTIR) was used to study the intermolecular interactions between VSM and wood. The antifungal performance of the VSM-treated wood was evaluated. The study revealed that VSM had good sustained-release performance and decay resistance. Mass losses of VSM-treated wood after leaching and exposure to Trametes versicolor (L.) Quel. and Gloephyllum trabeum (Pers.) Murrill decreased from mass losses of 20.8 % and 15.9 % of the control group to 9.2 % and 6.4 %, respectively. VSM treatment disrupted the mycelium of T. versicolor and G. trabeum, inhibited their respiratory metabolism, and the ligninase-laccase enzyme activity of T. versicolor. Meanwhile, MOR and MOE of VSM-treated wood were 96.7 MPa and 12.3 GPa which were 28.8 % and 11.5 % higher than the control group, respectively.
{"title":"Vanillin/silica microencapsulation for wood preservation","authors":"Li Yan, Zeyao Yan, Jiang Chen, Zhang-jing Chen, Yafang Lei","doi":"10.1515/hf-2022-0187","DOIUrl":"https://doi.org/10.1515/hf-2022-0187","url":null,"abstract":"Abstract Vanillin is an antifungal and environmentally friendly compound. In this study, vanillin and silica microcapsules (VSM) were microencapsulated using the sol-gel method and then impregnated into wood. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDXA) and transmission electron microscopy (TEM) were used to characterize the morphological structure and distribution of VSM in wood. Fourier transform infrared spectroscopy (FTIR) was used to study the intermolecular interactions between VSM and wood. The antifungal performance of the VSM-treated wood was evaluated. The study revealed that VSM had good sustained-release performance and decay resistance. Mass losses of VSM-treated wood after leaching and exposure to Trametes versicolor (L.) Quel. and Gloephyllum trabeum (Pers.) Murrill decreased from mass losses of 20.8 % and 15.9 % of the control group to 9.2 % and 6.4 %, respectively. VSM treatment disrupted the mycelium of T. versicolor and G. trabeum, inhibited their respiratory metabolism, and the ligninase-laccase enzyme activity of T. versicolor. Meanwhile, MOR and MOE of VSM-treated wood were 96.7 MPa and 12.3 GPa which were 28.8 % and 11.5 % higher than the control group, respectively.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42579201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Vaziri, Christopher H. Dreimol, Lars Abrahamsson, P. Niemz, D. Sandberg
Abstract The wood–water interactions of welded bond-lines of European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) were in this paper studied for the first time with dynamic vapour sorption equipment. The aim of this study was to characterize the water sorption in the welded bond-line and to define to which extent it deviates from water sorption of the unwelded wood. The objective was to provide deepened knowledge about water sorption of the welded bond-line, which could be used to improve the moisture resistance of welded wood in the future. The welded wood generally had lower equilibrium moisture contents than the unwelded wood. The welded bond-lines of beech and pine showed greater hysteresis than the unwelded wood from 0 to 55 % relative humidity. All specimens showed faster adsorption than desorption. However, the welded wood showed slower adsorption but faster desorption than unwelded wood. The time to complete half of the fractional change in moisture content (E(t) = 0.5) increased as the moisture content increased. The adsorption diffusion coefficients of beech and welded beech were higher than those of pine and welded pine up to 50 % and 40 % RH, respectively. In desorption, pine had a higher diffusion coefficient than beech in the whole range of 85–0 % RH. Analogously, welded pine had a higher diffusion coefficient than welded beech in the range of 85–5 % RH. In contrast to the desorption, the welded wood always had lower adsorption diffusion coefficients than the corresponding unwelded wood. The diffusion coefficients showed irregular patterns in some ranges of the RH. Therefore, it was hard to make a clear conclusion about the water-sorption behaviour of the specimens based on the defined diffusion coefficients.
{"title":"Water-vapour sorption of welded bond-line of European beech and Scots pine","authors":"M. Vaziri, Christopher H. Dreimol, Lars Abrahamsson, P. Niemz, D. Sandberg","doi":"10.1515/hf-2022-0012","DOIUrl":"https://doi.org/10.1515/hf-2022-0012","url":null,"abstract":"Abstract The wood–water interactions of welded bond-lines of European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.) were in this paper studied for the first time with dynamic vapour sorption equipment. The aim of this study was to characterize the water sorption in the welded bond-line and to define to which extent it deviates from water sorption of the unwelded wood. The objective was to provide deepened knowledge about water sorption of the welded bond-line, which could be used to improve the moisture resistance of welded wood in the future. The welded wood generally had lower equilibrium moisture contents than the unwelded wood. The welded bond-lines of beech and pine showed greater hysteresis than the unwelded wood from 0 to 55 % relative humidity. All specimens showed faster adsorption than desorption. However, the welded wood showed slower adsorption but faster desorption than unwelded wood. The time to complete half of the fractional change in moisture content (E(t) = 0.5) increased as the moisture content increased. The adsorption diffusion coefficients of beech and welded beech were higher than those of pine and welded pine up to 50 % and 40 % RH, respectively. In desorption, pine had a higher diffusion coefficient than beech in the whole range of 85–0 % RH. Analogously, welded pine had a higher diffusion coefficient than welded beech in the range of 85–5 % RH. In contrast to the desorption, the welded wood always had lower adsorption diffusion coefficients than the corresponding unwelded wood. The diffusion coefficients showed irregular patterns in some ranges of the RH. Therefore, it was hard to make a clear conclusion about the water-sorption behaviour of the specimens based on the defined diffusion coefficients.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42101203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}