Mayu Ueda, Masashi Nakamura, A. Kitamori, K. Komatsu
Warm color of wood is a very important design factor for building materials, furniture, and so on. Therefore, color measurements for the surfaces of timber and wood products are often performed using a colorimeter. However, most of such color data are mean values inside a confined measurement area, and these values are entirely compared and evaluated based on L, a, b and ΔE values. In the present study, surface colors of sugi timbers (Cryptomeria japonica) dried by five different conditions were measured using an imaging spectrometer, and surface colors of 4 parts (heartwood-latewood, heartwood-earlywood, sapwood-latewood, and sapwood-earlywood) were examined for each drying condition based on the three color attributes (lightness L, chroma C, and hue angle H °). The color analysis revealed very clear linear relations between H ° and L regardless of drying conditions. Although the surface colors of the 4 parts were clearly distinguished from each other in the air-drying condition, the range of hue angle became narrow as the drying conditions became more severe and it was difficult to distinguish the two parts of heartwood-earlywood and sapwood-latewood by their colors. Originally bright surfaces such as the sapwood-earlywood part selectively darkened (lower lightness) and deepened (higher chroma) by the kiln drying.
木材的暖色是建筑材料、家具等的一个非常重要的设计因素。因此，木材和木制品表面的颜色测量通常使用色度计进行。然而，这些颜色数据大多是在一个有限的测量区域内的平均值，这些值完全是基于L, a, b和ΔE值进行比较和评估的。利用成像光谱仪对五种不同干燥条件下杉木(Cryptomeria japonica)的表面颜色进行了测定，并根据3种颜色属性(亮度L、色度C和色相角H°)对每种干燥条件下4个部分(心材-晚木、心材-早木、边材-晚木和边材-早木)的表面颜色进行了测定。颜色分析显示，无论干燥条件如何，H°和L之间都存在非常明确的线性关系。虽然在风干条件下4个部分的表面颜色有明显的区别，但随着干燥条件的加重，色相角度的范围变窄，心材-早木和边材-晚木两部分的颜色难以区分。原本明亮的表面，如sapwood-earlywood部分选择性地变暗(低亮度)和加深(高色度)通过窑干燥。
{"title":"Minute Color Measurement of Sugi Timber (Cryptomeria japonica) Dried by Five Conditions II.","authors":"Mayu Ueda, Masashi Nakamura, A. Kitamori, K. Komatsu","doi":"10.2488/JWRS.59.339","DOIUrl":"https://doi.org/10.2488/JWRS.59.339","url":null,"abstract":"Warm color of wood is a very important design factor for building materials, furniture, and so on. Therefore, color measurements for the surfaces of timber and wood products are often performed using a colorimeter. However, most of such color data are mean values inside a confined measurement area, and these values are entirely compared and evaluated based on L, a, b and ΔE values. In the present study, surface colors of sugi timbers (Cryptomeria japonica) dried by five different conditions were measured using an imaging spectrometer, and surface colors of 4 parts (heartwood-latewood, heartwood-earlywood, sapwood-latewood, and sapwood-earlywood) were examined for each drying condition based on the three color attributes (lightness L, chroma C, and hue angle H °). The color analysis revealed very clear linear relations between H ° and L regardless of drying conditions. Although the surface colors of the 4 parts were clearly distinguished from each other in the air-drying condition, the range of hue angle became narrow as the drying conditions became more severe and it was difficult to distinguish the two parts of heartwood-earlywood and sapwood-latewood by their colors. Originally bright surfaces such as the sapwood-earlywood part selectively darkened (lower lightness) and deepened (higher chroma) by the kiln drying.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88724101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of Composite Beams with Incomplete Interaction I.","authors":"Satomi Sonoda","doi":"10.2488/JWRS.59.211","DOIUrl":"https://doi.org/10.2488/JWRS.59.211","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83561344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Sueyoshi, T. Morikawa, Y. Tsunetsugu, Y. Kubojima, M. Tonosaki
{"title":"Sound Absorbing Performance of Wood Slit Panels","authors":"S. Sueyoshi, T. Morikawa, Y. Tsunetsugu, Y. Kubojima, M. Tonosaki","doi":"10.2488/JWRS.59.29","DOIUrl":"https://doi.org/10.2488/JWRS.59.29","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87511192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Japan Wood Research Society (JWRS) takes great pleasure in inviting all members of our society with an interest in the science and technology of wood to attend the 64th Annual Meeting of the JWRS that will be held from March 13 to 15, 2014, Matsuyama city, Ehime, Japan. The society members may make oral and poster presentations during the meeting. The symposium and the exhibition of the related companies will also be held. For more information please visit the following web site: http://www.jwrs.org/wood2014/.
{"title":"Bending and Panel Shearing Deterioration of Plywood Used for the Floor Sheathing for a Long Period","authors":"Naoyuki Furuta, Y. Hirabayashi, T. Hirai","doi":"10.2488/JWRS.59.287","DOIUrl":"https://doi.org/10.2488/JWRS.59.287","url":null,"abstract":"The Japan Wood Research Society (JWRS) takes great pleasure in inviting all members of our society with an interest in the science and technology of wood to attend the 64th Annual Meeting of the JWRS that will be held from March 13 to 15, 2014, Matsuyama city, Ehime, Japan. The society members may make oral and poster presentations during the meeting. The symposium and the exhibition of the related companies will also be held. For more information please visit the following web site: http://www.jwrs.org/wood2014/.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80966697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Results of Outdoor Exposure Test for Sugi Glulam I.","authors":"Y. Yanagawa","doi":"10.2488/JWRS.59.255","DOIUrl":"https://doi.org/10.2488/JWRS.59.255","url":null,"abstract":"","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81643830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hirokazu Ito, M. Okamoto, Rie Makise, A. Isa, E. Fujinaka, Y. Kojima, Shigehiko Suzuki, T. Endo, Yoshikuni Teramoto
In the present study, we modified micro-fibrillated cellulose (MFC) mechano-chemically by a surface treatment with calcium silicate hydrate, in order to develop an effective filler material for producing wood-plastic composites (WPC). The surface modification could be performed efficiently by the combination of a wet ball-milling process in the presence of silica powder and Ca(OH)2 and a subsequent hydrothermal treatment, giving rise to a formation of tobermorite crystals of calcium silicate hydrate. The surface-treated MFC products exhibited high heat resistance and no irreversible aggregation even after normal heat-drying at 60°C. By an addition of the modified MFC filler to polypropylene-based WPC, the composite materials demonstrated high mechanical strength and high elastic modulus.
{"title":"Surface Treatment of Micro-fibrillated Cellulose Using Calcium Silicate Hydrate","authors":"Hirokazu Ito, M. Okamoto, Rie Makise, A. Isa, E. Fujinaka, Y. Kojima, Shigehiko Suzuki, T. Endo, Yoshikuni Teramoto","doi":"10.2488/JWRS.59.375","DOIUrl":"https://doi.org/10.2488/JWRS.59.375","url":null,"abstract":"In the present study, we modified micro-fibrillated cellulose (MFC) mechano-chemically by a surface treatment with calcium silicate hydrate, in order to develop an effective filler material for producing wood-plastic composites (WPC). The surface modification could be performed efficiently by the combination of a wet ball-milling process in the presence of silica powder and Ca(OH)2 and a subsequent hydrothermal treatment, giving rise to a formation of tobermorite crystals of calcium silicate hydrate. The surface-treated MFC products exhibited high heat resistance and no irreversible aggregation even after normal heat-drying at 60°C. By an addition of the modified MFC filler to polypropylene-based WPC, the composite materials demonstrated high mechanical strength and high elastic modulus.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82861270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Harada, A. Miyatake, D. Kamikawa, Yasushi Hiramatsu, K. Shindo, A. Inoue, K. Miyamoto, S. Tohmura, Y. Hatano, Masayuki Miyabayashi
In order to discuss how adhesive strength at elevated temperature affects the fire resistance of glued laminated timber (GLT), structural GLT beams using adhesives of phenol-resorcinol-formaldehyde (PRF) resin, aqueous polymer isocyanate (water based polymer-isocyanate, API) resin or polyvinyl acetate (PVAc) resin were made and their fire performances were evaluated. The PRF-GLT beams and API-GLT beams exhibited the fire performance required for the 45-minute fire test. However, the PVAc-GLT beams failed to withstand the fire test because the laminae separated earlier than PRF-GLT and API-GLT. The adhesive shear strengths in laminated wood at elevated temperature were evaluated. They decreased with rising temperature, and were found to be RF>API>PVAc at 100°C, 150°C and 200°C. In particular, PVAc decreased drastically, where the adhesive strength at 150 °C was almost null. The fire resistance degradation of GLT beams is dominated by the loss of laminae, and depends on the adhesive shear strength in laminated wood. If the adhesive shear strength at 200 °C is enough to keep laminae from separating, the GLT beam specimens are expected to exhibit 45minute quasi-fireproof performance.
{"title":"Temperature Dependence of Adhesive Strength and Fire Resistance of Structural Glued Laminated Timber Beams","authors":"T. Harada, A. Miyatake, D. Kamikawa, Yasushi Hiramatsu, K. Shindo, A. Inoue, K. Miyamoto, S. Tohmura, Y. Hatano, Masayuki Miyabayashi","doi":"10.2488/JWRS.59.219","DOIUrl":"https://doi.org/10.2488/JWRS.59.219","url":null,"abstract":"In order to discuss how adhesive strength at elevated temperature affects the fire resistance of glued laminated timber (GLT), structural GLT beams using adhesives of phenol-resorcinol-formaldehyde (PRF) resin, aqueous polymer isocyanate (water based polymer-isocyanate, API) resin or polyvinyl acetate (PVAc) resin were made and their fire performances were evaluated. The PRF-GLT beams and API-GLT beams exhibited the fire performance required for the 45-minute fire test. However, the PVAc-GLT beams failed to withstand the fire test because the laminae separated earlier than PRF-GLT and API-GLT. The adhesive shear strengths in laminated wood at elevated temperature were evaluated. They decreased with rising temperature, and were found to be RF>API>PVAc at 100°C, 150°C and 200°C. In particular, PVAc decreased drastically, where the adhesive strength at 150 °C was almost null. The fire resistance degradation of GLT beams is dominated by the loss of laminae, and depends on the adhesive shear strength in laminated wood. If the adhesive shear strength at 200 °C is enough to keep laminae from separating, the GLT beam specimens are expected to exhibit 45minute quasi-fireproof performance.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80057706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hiromi Takimoto, K. Yasue, M. Tokumoto, T. Takeda, T. Nakano
Observations were made of within annual ring and pith-to-bark variations of the microfibril angle of the S2 layer (MF angle) of tracheid walls in 106-year-old plantation trees of Japanese larch (Larix kaempferi Carr.). The MF angle was measured by the iodine method. The MF angle within the annual ring decreased from the beginning to the end region of earlywood, whereas in latewood there was less variation than in earlywood, regardless of cambial age. The decrease in MF angle in earlywood is gradual in rings of younger cambial age, whereas it is abrupt in rings of older cambial age, regardless of the rate of radial growth. The pith-to-bark variations of MF angle were found to be constant in earlywood. On the other hand, the MF angle of latewood decreased abruptly in the younger stage followed by a stable smaller angle in the older stage after the 15th to 30th rings. There was no significant correlation between ring width and MF angle of latewood in mature wood (after the 30th ring).
{"title":"Within Annual Ring and Pith-to-bark Variations of the Microfibril Angle in the S2 Layer of Tracheid Walls in 106-year-old Plantation Trees of Japanese Larch","authors":"Hiromi Takimoto, K. Yasue, M. Tokumoto, T. Takeda, T. Nakano","doi":"10.2488/JWRS.59.121","DOIUrl":"https://doi.org/10.2488/JWRS.59.121","url":null,"abstract":"Observations were made of within annual ring and pith-to-bark variations of the microfibril angle of the S2 layer (MF angle) of tracheid walls in 106-year-old plantation trees of Japanese larch (Larix kaempferi Carr.). The MF angle was measured by the iodine method. The MF angle within the annual ring decreased from the beginning to the end region of earlywood, whereas in latewood there was less variation than in earlywood, regardless of cambial age. The decrease in MF angle in earlywood is gradual in rings of younger cambial age, whereas it is abrupt in rings of older cambial age, regardless of the rate of radial growth. The pith-to-bark variations of MF angle were found to be constant in earlywood. On the other hand, the MF angle of latewood decreased abruptly in the younger stage followed by a stable smaller angle in the older stage after the 15th to 30th rings. There was no significant correlation between ring width and MF angle of latewood in mature wood (after the 30th ring).","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82495175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper deals with testing the stress distributions and strength in single-lap adhesive joints of bamboo plate adherends after being subjected to static bending moments. Stress and strain were calculated using an elastic and orthotropic finite-element method (FEM). In addition, the surface strain distributions of single-lap adhesive joints under static bending moments were measured using strain gauges. Reasonable correlation was found between the numerical and the experimental results. It was found that the maximum value of the maximum principal stress, σ1, appears at the interface between the adhesive layer and the adherend. The normal stress in the direction perpendicular to the fiber was greatest near the singular points. Bending strength tests were performed. In the case where the width of the joints and the lapped length were equal, it was found that the bending strength was maximal. Furthermore, the joint strength was predicted using two singularity parameters from the calculation results. Fairly good agreement was found between the predictions and the experimental results.
{"title":"The Stress and Strength Evaluations of Single-lap Adhesive Joints of Bamboo Plate Adherends under Static Bending Moments","authors":"I. Higuchi","doi":"10.2488/JWRS.59.383","DOIUrl":"https://doi.org/10.2488/JWRS.59.383","url":null,"abstract":"This paper deals with testing the stress distributions and strength in single-lap adhesive joints of bamboo plate adherends after being subjected to static bending moments. Stress and strain were calculated using an elastic and orthotropic finite-element method (FEM). In addition, the surface strain distributions of single-lap adhesive joints under static bending moments were measured using strain gauges. Reasonable correlation was found between the numerical and the experimental results. It was found that the maximum value of the maximum principal stress, σ1, appears at the interface between the adhesive layer and the adherend. The normal stress in the direction perpendicular to the fiber was greatest near the singular points. Bending strength tests were performed. In the case where the width of the joints and the lapped length were equal, it was found that the bending strength was maximal. Furthermore, the joint strength was predicted using two singularity parameters from the calculation results. Fairly good agreement was found between the predictions and the experimental results.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72942569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Properties of deodorizing filters for tobacco gas with activated carbon made from pruned apple branches on H2O-activation with loaded reagent was investigated by comparison with the commercial activated carbon from coconut shells. The results are as follows. Both external specific surface area and mesopore volume were larger in the experimental than in the commercial activated carbon. Besides it was not found that in the range where it was limited, the distribution of micropores and mesopores was lower. Activated carbon from pruned apple branches showed a faster removal time of tobacco gas from an early period of use in a fixed period of time. This was assumed to be caused by the large external specific surface area and mesopore volume.
{"title":"Properties of Deodorizing Filters with Activated Carbon from Pruned Apple Branches","authors":"T. Hirose, M. Kushibiki","doi":"10.2488/JWRS.59.391","DOIUrl":"https://doi.org/10.2488/JWRS.59.391","url":null,"abstract":"Properties of deodorizing filters for tobacco gas with activated carbon made from pruned apple branches on H2O-activation with loaded reagent was investigated by comparison with the commercial activated carbon from coconut shells. The results are as follows. Both external specific surface area and mesopore volume were larger in the experimental than in the commercial activated carbon. Besides it was not found that in the range where it was limited, the distribution of micropores and mesopores was lower. Activated carbon from pruned apple branches showed a faster removal time of tobacco gas from an early period of use in a fixed period of time. This was assumed to be caused by the large external specific surface area and mesopore volume.","PeriodicalId":17248,"journal":{"name":"Journal of the Japan Wood Research Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80854548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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