人造板弹性模量测量不确定度的评定

按照JJF—1059—1999《测量不确定度评定与表示》的方法,对中密度纤维板弹性模量测量试验中影响其测量结果不确定度进行了分析和评定。     

胶合板胶合强度测试中不确定度评定

依据GB/T 9846-2004《胶合板》标准,对胶合板胶合强度测试过程进行研究,分析了胶合强度测量过程主要不确定度的来源并对其进行评定。介绍了胶合强度测量不确定度的评定方法和步骤,对各不确定度分量进行量化,得到了胶合强度的合成不确定度和扩展不确定度。     

加载速度对静曲强度数值的影响

随着社会主义市场经济的发展，产品市场竞争越来越激烈，产品质量是企业的生命，谁产品质量好，谁就能占领市场，企业就有生命力。但同时对质量监督人员的技术水平也有了更高的要求。即要在检测过程中，不断提高检测质量水平。我国人造板质量检测工作起步不久，积累的经验还不够丰富，为了更好地对人造板的质量进行检测，本文就加载速度对刨花板静曲强度的影响进行了探讨，因为静曲强度是刨花板，特别是结构刨花板最重要的一个性能指标。根据现在执行的刨花板国家标准GB／T4897－92，规定单项测试静曲强度时，不分段加载，加载时间控制在3…     

干燥器法测定人造板甲醛释放量的不确定度评定

通过干燥器对人造板甲醛释放量测定过程进行研究,系统分析了整个测量过程的不确定度的来源并对其进行评定,对各不确定度分量进行了量化,在此基础上提出了该方法的合成不确定度。     

无胶刨花板静曲强度影响因子

为探讨化学试剂活化处理木质刨花板的方法,采用氧化剂(硝酸)和特制交联剂处理柞木刨花,在特定工艺条件形成化学键制成无胶刨花板。结果表明:氧化剂含量和交联剂含量显著地影响无胶刨花板静曲强度;随着氧化剂含量和交联剂含量的增加,无胶刨花板静曲强度呈递增趋势,当氧化剂浓度为1.3%,交联剂含量为5%时,静曲强度达到最大为8.72 MPa。     

浸渍纸层压木地板内结合强度不确定度评定

依照JJF 1059.1-2012《测量不确定度评价与表示》的方法,对浸渍纸层压木地板内结合强度测量试验中影响其测量结果不确定度进行了分析和评定。结果表明：浸渍纸层压木地板内结合强度为：σ=（1.04±0.01）MPa,其中扩展不确定度的包含因子k=2,置信概率p=95%。     

干燥器法检测人造板甲醛释放量的主要影响因素及不确定度

【目的】针对干燥器法检测人造板甲醛释放量存在的重现性差、准确度不高等问题,研究干燥器法检测过程中的主要影响因素及不确定度,为干燥器法甲醛检测标准改进提供技术支持和理论依据。【方法】以饰面刨花板为研究对象,考察吸收水量和板材承载率对板材甲醛释放量干燥器法检测结果的影响,同时分析干燥器法检测过程中各种不确定度的来源,计算其不确定度。【结果】当吸收水量由20 m L增至300 m L时,板材甲醛稳定释放值从49μg增至72μg,当板材承载率由0.037 m2·m-3增至17.6 m2·m-3时,单位承载率下板材甲醛稳定释放值由2.14 mg·L-1降至0.88 mg·L-1。板材甲醛释放量越低,其干燥器法检测值偏差越大,40 L干燥器法的测量不确定度较9～11 L干燥器法更高。在不确定度的主要来源中,重复测量引入的不确定度对总体不确定度的贡献最大。【结论】吸收水量与板材甲醛释放量呈正相关,承载率与板材甲醛释放量呈负相关。在试验过程中,每个步骤都应严格按照标准规范操作,以保证数据的准确性和可靠性。     

纤维板的静曲弹性模量及静曲强度的动态检测

利用振动无损检测法测得纤维板的动态静曲弹性模量,并用一元和二元回归分析了纤维板的密度、静态静曲弹性模量、动态静曲弹性模量、静曲强度之间的相关性。结果表明:纤维板的静态静曲弹性模量与动态静曲弹性模量之间,或动态静曲弹性模量与静曲强度之间均密切线性相关;以纤维板的动态静曲弹性模量和密度为自变量与静曲强度建立的二元回归方程,其相关程度较一元回归更为密切。密度及长度与横截面面积比值较大的纤维板,其动态静曲弹性模量与静态值较为接近。     

影响湿法硬质纤维板静曲强度和吸水率测试结果的几项因素

静曲强度,吸水率是湿法硬质纤维板的两项重要指标。本文对影响静曲强度、吸水率测试结果的因素进行了试验与分析。     

Evaluation of wood-based panel durability using bending properties after accelerated aging treatments

The durability of wood-based panels was evaluated by comparing the bending properties of panels subjected to five accelerated aging treatments with the bending properties of panels that had experienced 5 years of outdoor exposure in Shizuoka City, Japan. In each accelerated aging treatment, methylene diphenyl diisocyanate-bonded panels showed higher bending retention than phenol formaldehyde (PF)-bonded panels. The bending retentions after six repeated cycles of the JIS-B, APA D-1, and ASTM treatments showed a correspondence of nearly one-to-one in the data for the three different treatments. The Shizuoka City 5-year outdoor exposure test data showed that the bending retentions of all panels decreased with time. In particular, the bending retentions of PF resin-bonded particleboard and oriented strandboard made from aspen were less than 30% and 10% of the original values, respectively, after the 5-year exposure period. The deterioration of the bending properties after the 5-year outdoor exposure in Shizuoka City was the same as that for six repetitions of the ASTM treatment.     

中国人造板业开始重新"洗牌"

今年8月,全国人造板行业捷报频传:8月5日,年产中(高)密度纤维板82万立方米的全国人造板行业领跑者——浙江丽人集团与德国迪芬巴赫公司合资3.8亿元在丽水建成投产了我国第一条20万立方米中高密度纤维板生产线;8月28日,中国包装行业和有色金属行业的优秀企业、国家高新企业——江苏大亚集团公司进军中国人造板业,总投资5.5亿元,建成又一条20万立方米的中(高)密度纤维板引进生产线,并力争在3至5年内投资50亿元,将大亚木业建成一个拥有13.3万公顷速生林基地,300万立方米人造板制造中心,5000万平方米强化地板、800万平方米实木复合地板和2亿美元出口家具的世界级森工企业集团。业内人士认为,引进先进生产线的涌入,标志着——     

家具结构板件中人造板性能差异探讨

依据家具结构中人造板常见应用形式,通过设计平面弯曲、侧向弯曲、板间剪切、平面剪切和集中载荷应力等5种应力模式实验,分析了胶合板、刨花板、中密度纤维板和定向刨花板等不同板材所产生的应力应变差别。结果表明,受力方式对这几种人造板的力学性能都有显著影响和差异,人造板侧面方向具有比平面方向更高的承受压力的能力,胶合板具有较高的承受侧向弯曲载荷和集中载荷的能力,中密度纤维板具有较高的承受平面弯曲载荷、板间剪切载荷和平面剪切载荷的能力,受力方式对几种板材蠕变特性的影响较大且差异较为显著。相关分析结果可供家具设计特征值参考。     

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

Introduction Multi-functional sensor, a new developmental direction of sensor field, can integrate several sense organs to measure several parameters at one time (Liu 1999). This sensor not only has small size but also has strong functions. Moreover, the …     

人造板与室内空气污染及治理

人造板具有淳朴自然、纹理美观、易于加工等优点,是室内装修、家具制造的主要材料。但在制板和使用过程中,所释放出的甲醛对室内空气造成污染,必须引起重视。作者提出了改善人造板环保性能和消除空气中甲醛污染的几点建议。     

中国人造板工业现状与入世对策

世界经济发展的总趋势告诉我们，一个国家及其任何一个产业部门如果不想被世界抛弃的话，就应当使自己融于世界经济之中。对于中国的人造板工业来说更是如此。我国的人造板工业近一二十年发展迅速。根据世界粮农组织（FAO）从１９２个国家１９９８年年报中得到的资料统计，目前     

Effects of panel density and particle type on the ultrasonic transmission through wood-based panels

Air-coupled ultrasonic inspection for the detection of delaminations inside panels is a widely applied technique in the wood-based panel industry. Additionally, the ultrasonic signal is used to monitor the constancy of the production process as unsteady material properties and process parameters cause variations in the transmitted ultrasonic signal. This article examines the physical effects of air-coupled ultrasonic testing and analyses the influences of panel density and particle type on the transmitted ultrasonic signal. The experiments were carried out for a broad range of wood-based panels. The experimental results indicate that the tested properties influence the transmission in two ways. Firstly, density affects the reflection and transmission factors at the material boundaries, and secondly, particles and pores act as scattering centres inside the material, leading to an attenuation of the ultrasonic signal. The results of this study may be used to efficiently include the ultrasonic signal into a trending system for the wood-based panel production process.     

Radial modulus of rupture in radiata pine measured by individual rings

New equipment was developed to measure the strength of individual annual rings in green wood under predominantly tensile stress. This equipment was then used to assess the variation of the radial modulus of rupture (rMOR) in thirty-six 25-year-old radiata pine trees taken from three sites in New Zealand. The rMOR for individual rings ranged from 4.2 to 12.7 MPa and was calculated on the assumption that during bending of the specimens fracture was caused by the tensile force in the radial direction (i.e., perpendicular to the tangential-longitudinal plane). No consistent trends were observed in rMOR from pith to bark; nor was there any evidence of differences between the three sites. However, there was substantial between-tree variability that manifested mainly in different average rMOR values for the trees rather than in variations from pith to bark. These results indicate that there are no concerns with respect to splitting resistance for the juvenile wood of radiata pine. It will be of interest to investigate whether splitting resistance is under genetic control.