Estimation of demand for wood panels in Iran by the year of 2012.

Considering increasing rate of Iran population and consumption of wood panels, the authors investigated the per capita consump- tion of wood panels during the years from 1997 to 2007. The exponential smoothing method was used to obtain a per capita consumption panern of wood panels in lran for estimating demand of wood panels by the year of 2012. Results show that the consumption of particleboard, fiberboard, and medium density fiberboard in lran will increase by 33%, 72% and 107 %o, respectively, by the year of 2012; however, the consumption of plywood will increase only by 7% by 2012. The deficient amount of wood panels in Iran is estimated over 1400 000 m^3. The results of this study provide the technique reference for planners of wood panel industries in Iran in capital investment decisions.

Nonlinear aspects of energy dissipation in wood-panel joints Sara Casciati

The joints connecting vertical and horizontal elements are the ＂weak link＂ in structural systems assembled from wood panels. If they are too weak, local failures may occur, resulting in performance that is significantly below expectations. If they are too resistant, the joints may be unable to dissipate energy during vibrations, thus possibly initiating a fast progressive failure. This paper re-processes and re-elaborates the results of shaking table tests previously carried out by the author and other co-workers. The goal is to assess the feasibility of a joint which is able to dissipate energy during vibration, without degrading the connection performance.

Nonlinear aspects of energy dissipation in wood-panel joints

We have found some mistakes in the article by Sara Casciati （2007）. The revisions are given below：

Estimation of demand for wood panels in Iran by the year of 2012

Considering increasing rate of Iran population and consumption of wood panels, the authors investigated the per capita consumption of wood panels during the years from 1997 to 2007.The exponential smoothing method was used to obtain a per capita consumption pattern of wood panels in Iran for estimating demand of wood panels by the year of 2012.Results show that the consumption of particleboard, fiberboard, and medium density fiberboard in Iran will increase by 33%, 72% and 107 %, respectively, by the year of 2012;however, the consumption of plywood will increase only by 7% by 2012.The deficient amount of wood panels in Iran is estimated over 1400 000 m3.The results of this study provide the technique reference for planners of wood panel industries in Iran in capital investment decisions.

Study on Improvement of Hygroscopicity of Magnesite-Bonded Wood Wool Panel

Magnesite-bonded wood wool panel(MWWP)is an inorganic-bonded panel product in which wood excelsior is bonded with magnesite.Lowering the hygroscopicity is one of the key measures to improve the quality of the panel.In this study,moisture absorption mechanism of MWWP and measures generally applied to lower its hygroscopicity were reviewed.Three methods were then experimented to improve the dimensional stability of the panel,including adjusting the molar ratio of raw materials,adding additives and optimizing the conditioning process.The results showed that satisfying dimensional stability could be achieved when the molar ratio of MgO to MgCl_(2) was 5:1,the No.2 composite additive(aluminum powder+NH_(4)H_(2)PO_(4)+ferric alum)was adopted and a constant temperature and humidity treatment was applied in the first stage of conditioning.

Naturally Nitrogen-Doped Biochar Made from End-of-Life Wood Panels for SO_(2) Gas Depollution

Reconstituted wood panels have several advantages in terms of ease of manufacturing,but their shorter life span results in a huge amount of reconstituted wood panels being discarded in sorting centers yearly.Currently,the most common approach for dealing with this waste is incineration.In this study,reconstituted wood panels were converted into activated biochar through a two-step thermochemical process:(i)biochar production using pilot scale fast pyrolysis at 250 kg/h and 450℃;and(ii)a physical activation at three temperatures(750℃,850℃ and 950℃)using an in-house activation furnace(1 kg/h).Results showed that the first stage removed about 66% of the nitrogen from the wood panels in the form of NO,NH3,and trimethylamine,which were detected in small amounts compared to emitted CO_(2).Compared to other types of thermochemical conversion methods(e.g.,slow pyrolysis),isocyanic acid and hydrogen cyanide were not detected in this study.The second stage produced activated biochar with a specific surface area of up to 865 m^(2)/g at 950℃.The volatile gases generated during activation were predominantly composed of toluene and benzene.This two-step process resulted in nitrogen-rich carbon in the form of pyrrolic and pyridinic nitrogen.Activated biochars were then evaluated for their SO_(2) retention performance and showed an excellent adsorption capacity of up to 2140 mg/g compared to 65 mg/g for a commercial activated carbon(889 m^(2)/g).End-of-life reconstituted wood panels and SO_(2) gas are problematic issues in Canada where the economy largely revolves around forestry and mining industries.

A design and application of compound multi-functional sensor in wood-based panel processing

A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in details. The operational principles of different sensors, technical flow of manufacturing, development of software systems of special functions, and the assessments of technical specification were also be introduced. This sensor adopted many new technologies, such as the applications of piezoresistant effect and heat sensitive effect can effectively measure the pressure and temperature, digital signal processing technology was used to extract and treat signals, and resist interference, encapsulation technology was used to keep the normal run of sensor under a harsh environment. Thus, the on-line compound multi-functional temperature/pressure sensor can be applied better to supervise the production of wood-based panels. All technical specifications of the compound multi-functional sensor were tested and the results met the requirements of the equipments.

Soy Protein Isolate Non-Isocyanates Polyurethanes(NIPU)Wood Adhesives

Soy-protein isolate(SPI)was used to prepare non-isocyanate polyurethane(NIPU)thermosetting adhesives for wood panels by reacting it with dimethyl carbonate(DMC)and hexamethylene diamine.Both linear as well as branched oligomers were obtained and identified,indicating how such oligomer structures could further cross-link to form a hardened network.Unusual structures were observed,namely carbamic acid-derived urethane linkages coupled with lactam structures.The curing of the adhesive was followed by thermomechanical analysis(TMA).It appeared to follow a two stages process:First,at a lower temperature(maximum 130℃),the growth of linear oligomers occurred,finally forming a physically entangled network.This appeared to collapse and disentangle,causing a decrease of MOE,as the temperature increases.This appears to be due to the ever more marked Brownian movements of the linear oligomer chains with the increase of the temperature.Second,chemical cross-linking of the chains appeared to ensue,forming a hardened network.This was shown by the thermomechanical analysis(TMA)showing two distinct MOE maxima peaks,one around 130℃ and the other around 220℃,with a very marked MOE decrease between the two.Plywood panels were prepared and bonded with the SPI-NIPU wood adhesive and the results obtained are presented.The adhesive appeared to pass comfortably the requirements for dry strength of relevant standards,showing to be suitable for interior grade plywood panels.It did not pass the requirements for wet tests.However,addition of 15%of glycerol diglycidyl ether improved the wet tests results but still not enough to satisfy the standards requirements.

Lignocellulosic Micro and Nanofibrillated Cellulose Produced by Steam Explosion for Wood Adhesive Formulations

The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose(L-MNFCs)obtained from Eucalyp-tus Globulus bark in Urea-Formaldehyde UF adhesive was tested.L-MNFCs were prepared by an environmentally friendly,low-cost process using a combination process involving steam explosion followed by refining and ultra-fine grinding.Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets.They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20μm,respec-tively.The effects of the addition of low amounts of L-MNFCs(1%wt.)on the properties of three different adhe-sives(Urea-Formaldehyde UF,Phenol-Formaldehyde PF,and Tannin-Hexamine TH)were studied by the evolution of the pH,the viscosity,and the mechanical properties.Results showed that the viscosity of PF and UF adhesives increased with the addition of L-MNFCs,unlike TH.Meanwhile,the addition led to better mechan-ical behavior for the three adhesives.Particleboards were then prepared using modified UF with L-MNFCs and tested.Results showed that an amount of 1%wt.of L-MNFCs was sufficient to increase the internal bonding by≈67%,the modulus of elasticity by≈43%,and the modulus of rupture by≈29%.

Study on the Preparation Process Optimization of Plywood Based on a Full Biomass Tannin-Sucrose Wood Adhesive

Biomass adhesive is conducive to decreasing the dependence of the wood adhesive industry on synthetic resin based on fossil resources and improving the market competitiveness of adhesives.It is also a critical breakthrough to realize the goal of carbon peaking and carbon neutrality in the wood industry.In this study,a full biomass wood adhesive composed of tannin and sucrose was developed and applied successfully to the preparation of ply-wood.The preparation technique of plywood was optimized,and the chemical structure,curing performance,crystallization property and thermal performance of the adhesive were investigated.Results showed that:(1)hot-pressing temperature played a decisive role in the performances of tannin-sucrose composite adhesives and it also had a very significant influence on the water resistance of plywood.(2)The preparation of tannin-sucrose composite adhesive was a process in which sucrose was transformed into furan aldehydes and then made cross-linking reaction with tannin.These composite adhesives could only get good bonding performances when the curing temperature was above 210℃.(3)The optimal plywood preparation technique was:hot-pressing tem-perature of 220℃,hot-pressing time of 1.2 min/mm,m(tannin):m(sucrose)of 60:40,and adhesive loading of 160 g/m^(2).The wet bonding strength in boiling water of the prepared plywood was 0.83 MPa,meeting the strength requirements of Type-I plywood in the standard of GB/T 17657-2013.(4)The curing temperature of tannin-sucrose composite adhesive was further decreased by lowering the temperature during the transformation of sucrose into 5-HMF,which was a key in subsequent research.

注意力可变形卷积网络的木质板材瑕疵识别

为了解决木材缺陷检测中人工成本高、效率低的问题,该文基于可变性卷积网络和注意力机制,提出一种端到端的神经架构模型.首先,可变形卷积网络(Deformable Convolutional Network, DCN)通过将矩形网格转换为变形网格,使模型专注于具有更多有用图像信息的区域.使用可变形卷积网络可以忽略图像特征中不相关的系数,解决了传统卷积在特征中学习更多信息能力有限的问题.然后,将DCN输出馈送到门控循环单元(Gated Recurrent Unit, GRU)层以学习缺陷图像的高级特征.最后,通过关注输入图像的最重要特征,应用注意力机制加强瑕疵区域的高亮度,从而提高模型识别的准确性.使用Matlab平台在4个木质板材缺陷数据集上将该文方法与现有其他方法进行比较分析,该文方法的准确率比其他3种对比方法提高了2.4%~13.2%的维度,灵敏度提高了3.3%~16.6%的维度,特异性提高了4%~21%的维度.实验结果表明,该文方法在检测精度和其他各个性能方面均优于现有方法,最佳准确率为99.2%,证明了该文方法的有效性.

室内空间中人造板的隔声性能及规律研究

人造板作为室内装饰、装修的重要材料之一,会对室内空间的声学环境产生重要影响,研究人造板在室内空间中的隔声性能具有重要意义。基于此,本研究分别对人造板单板结构、箱框结构和以石膏板为背板的箱框结构的隔声性能进行分析。结果表明,板材类型对隔声性能具有显著影响,在单板结构中胶合板相较其它板材具有良好的隔声性能;箱框结构能够显著提高单板结构的隔声性能,五种人造板制成的箱框结构的隔声量分别提升了30.77%(中纤板)、7.14%(胶合板)、29.17%(刨花板)、44.00%(指接板)和18.52%(细木工板);另外,采用胶结合连接的人造板-石膏板箱框结构能够保持良好的隔声性能。这能为人造板在室内空间的应用和室内环境优化提供科学依据。

2011—2021年欧盟地区木材及人造板生产情况分析

欧盟是中国木材及人造板最大贸易伙伴之一。针对2011—2021年欧盟地区木材、人造板产量变化趋势以及木材加工行业的经营业绩和就业人数进行整理并加以分析,以期为我国木材加工及人造板从业人员提供参考和借鉴。

基于一般化双重钻石模型的人造板国际竞争力影响因素研究

基于一般化双重钻石模型理论,采用20个主要人造板出口国2000—2020年的数据,运用面板数据模型实证分析人造板国际竞争力的影响因素。结果表明:(1)森林资源禀赋、相关支持性产业、竞争状态、国际贸易便利化条件是正向影响因素,劳动力成本、需求条件、国外竞争状态是负向影响因素;(2)不同发展水平国家和不同板种的影响因素存在差异。森林资源禀赋、需求条件、国际市场需求是发达国家形成国际竞争力的主要因素,而在发展中国家,相关支持性产业水平、竞争状态十分重要。与纤维板、刨花板相比,胶合板国际竞争力更依赖森林资源禀赋,对劳动力成本上升更敏感,受相关支持性产业水平、贸易便利化影响更大。为提升中国人造板国际竞争力,应利用高端市场改善需求条件,推进工业原料林建设以保障木质原料供给,普及应用先进装备技术发挥相关支持性产业作用,利用国际合作新机遇获取贸易便利化条件,引导国内外资本投入到产业改造升级和新兴板种发展中。

生物质基胶黏剂的研究进展

我国的木材胶黏剂消耗量巨大,以丰富的生物质资源制备生物质基胶黏剂作为传统三醛树脂胶黏剂的补充具有重要的现实意义。本文综述了生物质原料在三醛树脂中的应用及生物质基胶黏剂的研究进展,展望了生物质基胶黏剂的发展趋势及研究方向,为我国生物质基胶黏剂行业未来发展提供参考。

中国人造板产业标准化发展30年回顾与展望

标准化在推动产品和服务质量提升、促进转型升级、推进高质量发展、保护消费者权益等方面都发挥着重要的支撑和引领作用。人造板标准化在中国人造板产业发展中发挥了重要作用。本文回顾了30年以来中国人造板产业标准化发展取得主要成就,结合建设支撑现代化人造板产业体系与人造板质量强国的需求,提出了中国人造板标准化工作未来发展目标和4项工作重点。

人造板产品生产许可证实施细则解读

从生产许可证实施细则起草者的角度和行业的角度对人造板产品生产许可证实施细则进行解读,对细则起草,特别是细则公布以后对全国各级许可证管理部门、检测机构、企业以及各方面咨询的问题进行梳理,按照细则的章节顺序给予解读。

室内人造板甲醛释放承载限量验证研究

通过实验测定不同类型的人造板在不同条件下的甲醛释放量,验证了人造板极限甲醛释放量最热月平均温度、最高月平均湿度校正系数,实际检测结果偏差为-25.7%~29.2%,基本符合温湿度校正系数换算数学模型。同时通过典型装修工程室内人造板甲醛释放量和使用量分析,以及实际室内空气甲醛含量检测,验证了人造板理论甲醛极限承载限量计算结果与实际检测结果基本相符。

木质素及其衍生物在木材胶黏剂中应用研究进展

以天然可再生资源替代传统化石资源开发绿色环保、性能优异的木材胶黏剂是人造板行业研究的热点。木质素来源广泛、价格低廉,且分子结构中含有羟基、甲氧基、羧基等活性基团,易于功能化修饰,是合成木材胶黏剂的理想原料。本文重点综述了木质素及其衍生物在酚醛树脂、脲醛树脂、环氧树脂、聚氨酯等合成树脂木材胶黏剂中的应用与研究现状,介绍了化学改性、降解、溶剂分级纯化等预处理方式对木质素化学反应活性及合成树脂胶黏剂力学性能的影响,探讨了木质素基木材胶黏剂目前发展面临的困难和挑战,并展望了未来应用及研究方向,以期为木质素资源的高效、高值化综合利用及高性能生物基木材胶黏剂的开发提供理论与技术参考。

基于改进粒子群算法的木材板材下料方法

木材板材在家具行业应用广泛,以绿色环保、节约能源为目的的木材板材优化下料已经成为研究的热点。木材板材下料优化问题属于二维矩形下料问题,是一种具有高度计算复杂性的问题。本研究主要针对单规格木材板材进行矩形零件下料问题,在木材板材长和宽都大于零件长和宽的情况下,通过建立二维下料的数学模型,采用标准粒子群算法、变邻域搜索算法、粒子群混合变邻域搜索算法分别进行求解,并以某企业的下料实例进行分析计算。首先,利用标准粒子群算法求解单规格板材下料问题;其次,利用变邻域搜索算法求解单规格板材下料问题。在获得局部最优解的基础上改变其邻域结构再进行局部搜索,找到另一个局部最优解,如此不断迭代,直到满足算法的终止条件,获得全局最优解;最后,利用粒子群变邻域搜索混合算法求解单规格板材下料问题。针对粒子群算法局部搜索能力较差、容易过早收敛的问题和具有较好包容性的特点,将变邻域搜索的思想融入粒子群算法中,使结果更加趋向全局最优。结果表明:粒子群变邻域搜索混合算法相比粒子群算法和变邻域算法效率都有显著提升,能显著提高该木材板材的利用率,增加企业经济效益。