最新刊期
期 0 ， 2020
- 摘要：The authors sought to determine a balance between drying quality of lumber and （drying） speed during the wood drying process. The criteria used was based on the cupping method, a new method presented in this paper, for continuously monitoring wood drying stresses. A stress detecting device was designed in which an eddy current sensor was used to continuously （measure） the critical drying stress deflection causing specimen cupping. The data were automatically collected and processed by a computer. Calibration and regression equations were used to evaluate different phases and deflection-drying time curves of cupped specimens under different drying （conditions.） A close relationship was developed between the deflection of cupped specimens and （drying） time resulting in a relative coefficient greater than 0.99. These results demonstrated that （automatic） and continuous detecting equipment could be used for monitoring wood drying stresses.关键词：Wood drying stress;Consecutive detection;Cupping method;Eddy current sensor
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发布时间：2021-02-08 - 摘要：This paper describes the drying characteristics of lumber from plantation grown Poplar [Populus×euamericana （Dode） Guineir cv’I-214’] and Chinese Fir （Cunninghamia lanceolata）. Two drying processes were used for this study: a continuous schedule and conventional step drying schedule. The results were analyzed and showed that plantation grown wood from Poplar and （Chinese） Fir were easy to dry. After being dried at 100℃, no internal checks occurred but there was some severe cross deformation in the lumber. The lumber dried by the continuous schedule had （better） drying quality with less drying stress and deformation than that dried by the conventional step schedule, on the whole.关键词：Plantation wood;Drying characteristics;Step schedule;Continuous schedule
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发布时间：2021-02-08 - 摘要：The authors used nanometer SiO2 （nano-SiO2）, incorporated with silane coupling agent, to modify UF resin in order to improve the bond strength and decrease the free formaldehyde content of the resin. In this article, the effects of nano-SiO2 content, coupling agent and dispersing methods on properties of the UF resin, such as viscosity, free formaldehyde content and bond strength, were analyzed and discussed. The test results indicated that 1% nano-SiO2 （No. HTSi-04） added to UF resin and mechanically blended provided the best results. Among the 3 kinds of coupling agents, KH-550 ranked first followed by KH-792 and KH-570.关键词：Urea formaldehyde （UF） resin;Nanometer SiO2;free formaldehyde;Bond strength
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- 244
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发布时间：2021-02-08 - 摘要：In order to determine the shear strength parallel to grain for small-diameter logs or thin lumber, this paper describes a new test method in which the width of the specimen was cut to half its standard size. The feasibility of using the modified shear specimen, as a substitute for a standard specimen, was determined by comparing the shear strength between modified and standard （specimens） from both Chinese Fir （Cunninghamia lanceolata） and Poplar I-214 [Populus × euramericana （Dode） Guineir cv.’I-214’] lumber. Results showed that the absolute values of the relative differences of the shear strength between the standard and modified specimens for matched （condition） were under 3%, and there was no significant difference at the 0.05 probability level. This provided a useful method for measuring the shear strength parallel to the wood grain for small or undersize timber.关键词：wood;Shear strength;test method;Normal （or Standard） shear specimen;(Modified) shear specimen
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发布时间：2021-02-08 - 摘要：In order to determine the effect of different drying conditions on the quality of timber, small diameter plantation grown Birch （Betula platyphylla and B. costata） logs were either air dried or kiln dried. Property indexes such as dimensional stability, deformation degree, hardness and cleavage strength were tested and the results were analyzed. According to the data, the authors found that the quality of the logs that were kiln-dried was better than those that were air-dried. They also found there were differences in properties in the kiln-dried logs dried under different drying schedules. A milder schedule based on relatively lower temperature and higher humidity could bring better drying quality. From the results, the authors concluded that kiln drying small diameter plantation grown timber produced better results than air drying.关键词：Drying condition;Small diameter log;Wood properties;Birch
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发布时间：2021-02-08 - 摘要：Two kinds of waterborne preservatives, Ammoniacal Copper Quaternary （ACQ） and Copper Triazole （CuAz）, were used to treat Siberian White Fir （Abies nephrolepis） logs by pressure impregnation. The influence of preservative concentration and post-drying style on the properties of the treated wood was analyzed in this paper. A statistical t-test revealed that under a given experimental condition, MOE and MOR of wood samples had changed only slightly after the preservative treatment. However, compared with control samples, the MOR of the wood treated with ACQ decreased, while the MOR of CuAz treated wood also decreased, but in a less obvious way, due to relatively low retention. The MOE of the treated wood was slightly higher, or the same, as that measured before treating.关键词：Ammoniacal copper quaternary （ACQ）;Copper triazole （CuAz）;mechanical properties
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- 308
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发布时间：2021-02-08 - 摘要：Through the orthogonal test, the effect of hydrothermal treatment on physical and （mechanical） properties of compressed Poplar （Populus ×euramericana spp.） lumber was studied. （Analysis） of the results showed that the optimum pretreatment parameters for the compressed Poplar lumber was 60 min and a moisture content of 15% when the temperature was at 130℃.关键词：Poplar;Hydrothermal pretreatment;compression;physical and mechanical properties
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发布时间：2021-02-08 - 摘要：It is important to be able to accurately and rapidly measure log diameter to efficiently and automatically process logs. This paper describes a computer graphic method to represent a three dimensional shape of a log. Basic cross-sectional data were obtained by passing logs, at a given speed, through a frame on which laser scanners had been installed. Images of the shape of the logs were then viewed on the computer screen where they could be manipulated such as changing the coordinates, zooming in or out, or rotating them.关键词：Three-dimensional representation;Laser scanner;Coordinate change;Log
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发布时间：2021-02-08 - 摘要：An expert system, for wood selection in the furniture or decorating products manufacturing industry, was designed and presented in this article. Detailed descriptions focused on working principles and designing rules for the system. Application of this system could be helpful in making an effective and reasonable utilization of wood resources.关键词：Expert system;wood industry;furniture;Decoration
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发布时间：2021-02-08 - 摘要：Manchurian Ash （Fraxinus mandshurica）, Manchurian Walnut （Juglans mandshurica） and Spruce （Picea jezoensis var. komarovii） lumber were selected to determine process variables to glued laminated timber （GLT） with water based polymeric—isocyanate adhesive. The influence factors, such as the pressure, pressing time and adhesive consumption, on shear strength of the glued laminated timber were investigated through the orthogonal test. The results indicated that optimum technological parameters for glued laminated timber manufacturing were as follows: pressure at 1.5 MPa for Spruce and 2.0 MPa for both Manchurian Ash and Manchurian Walnut lumber, pressing time for 60 minutes and the spread of 250 g/m2.关键词：Glued laminated timber;shear strength;Orthogonal test
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- 257
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发布时间：2021-02-08 - 摘要：This paper investigates six kinds of selected preservatives as antifungal and anti-insect （agents） for wood flooring and other wood products and their application, such as the compound of boride and sodium pentachlorophenol, organophosphorus agent, quaternary ammonium salts and pyrethroids. To evaluate their resistance against Coriolus versicolor and termites, a series of experiments for Korean Pine （Pinus koraiensis） wood sample were carried out. By comparison between treated samples and controls, the results showed the mixture of quaternary ammonium salts and pyrethroids was the most effective but least harmful preservative, and was suitable for wood flooring and other indoor wood products. The results also established a base for developing a standard for this preservative treatment.关键词：Wood-based flooring;Wood product;Antifungal and anti-insect agent;standard
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发布时间：2021-02-08
- Address：Box 29，Research Institute of Wood Industry, No. 1, Dongxiaofu, Haidian District, Beijing Postal code：100091
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