API胶粘剂在落叶松、白桦和柞木木材弦径面渗透的显微研究

利用显微照片对水性高分子异氰酸酯(API)胶粘剂在落叶松、白桦和柞木木材中的渗透性进行研究。结果表明：API胶粘剂在3种木材弦径面的渗透未看出有很大差别，即使木射线发达的柞木，在弦切面的木射线中也几乎看不到有API胶粘剂的渗入，说明木材弦面上的木射线没有起到引导API胶粘剂渗入木材内部的作用，文中分析了原因。     

快速强力木材胶粘剂

木材加工工业是应用胶粘剂数量最多的工业部门，目前世界范围内的木材用胶粘剂通常为脲醛树脂、酚醛树脂、王聚氰胶树脂、白乳胶及少量动植物蛋白胶和氯丁较。这些胶粘剂的历史发展悠久，用量也最大。统计资料显示国外木材胶粘剂的产量占胶粘剂总产量的47％，国内使用数量占合成胶粘剂总产量的70％～75％。然而上述木材胶存在固化时间长、初粘性差、固化时往往需要加温或加压等致命缺点，因此开发生产新型木材较具有重要意义。最新开发成功的快速强力木材胶具有如下特点：1．固化时间短：在常温和不加外压的情况下，0卜I。时～3小时即可固…     

强力木材胶粘剂

强力木材胶粘剂木材加工工业是应用胶粘剂数量最多的工业部门，现行脲醛、酚醛、白乳胶等木材胶存在固化时间长、初粘性差，固化时需要加温或加压等致命缺点，且生产成本较高。最新研制成功的木材胶克服了上述不足，广泛应用于胶合板、装饰板、家具和木器制造等多种木材加...     

木材胶粘剂用量的估算

木材胶粘剂用量的估算颜镇韩桐恩（中国林科院木材工业研究所北京１０００９１）（中华人民共和国林业部北京１００７１４）胶粘剂用量的多少，是衡量木材工业技术水平的标志之一，据１９８０年的统计数字，美国７０％以上的木材经过胶接加工［１］。我国的木材胶粘剂用量...     

快速强力木材胶粘剂

木材加工工业是应用胶粘剂数量最多的工业部门，目前世界范围内的木材用胶粘剂通常为脲醛树脂、酚醛树脂、三聚氰胺树脂、白乳胶及少量动植物蛋白胶和氯丁胶。这些胶粘剂的历史发展悠久，用量也最大。统计资料显示国外（如日本、德国）木材胶粘剂的产量占胶粘剂总产量的４７％，国内使用数量占合成胶粘剂总产量的７０％～７５％。然而上述木材胶存在固化时间长、初粘性差、固化时往往需要加温或加压等致命缺点，因此开发生产新型木材胶具有重要意义。产品特点１．固化时间短：在常温和不加外压的情况下，０．５ｈ～３ｈ即可固化，时间比现用木材胶缩短了１０倍～２０倍。２．粘接强度高：对木材的胶粘强度与白乳胶和其他树脂胶的相同或更高。３．初粘性好：能在０．５ｍｉｎ～３ｍｉｎ内初粘。４．产品没有毒性、刺激性和腐蚀性，价格便宜，原料来源丰富。若将该产品用于胶合板生产，可改变传统的加温加压粘接工艺，节省设备投资。用于家具制造可迅速常温不加压固化，缩短生产周期。本项产品的推广使用将给木材加工行业带来新的生命力。技术水平近年来，国内外科技工作者在木材胶的研究方面始终滞留在对现行木材胶的改性方法上。试验证明，如果不从根本上改变胶粘剂的结构，很难达到预期目的。我们在查阅...     

木材胶粘剂的作用和特性

木材胶粘剂的作用和特性颜镇，李亚兰，牛丽平（中国林科院木材工业研究所北京１０００９１）本文中的木材，定义为英国标准ＢＳ５４４２（１９７９）第３部分所述，是指实体木材和人造板；木材胶粘剂的定义是指将木材与木材或其它物体的表面胶接成一体的材料。随着新型胶...     

大豆基木材胶粘剂的研发

综述了20世纪70年代前大豆基木材胶粘剂开发应用和20世纪90年代以来国内外大豆基木材胶粘剂研发情况,以及大豆基木材胶粘剂开发中的关键性理论与方法。提出大豆基木材胶粘剂研发今后努力的方向。     

聚氨酯预聚体的合成及其在木材粘接领域的应用

本文研究了聚氨酯预聚体的合成工艺，测试了固化后的聚氨酯胶粘剂胶片的性能，讨论了分子结构对拉伸强度和伸长率的影响，同时进行了聚氨酯粘剂用于含水率木材粘接的试验，结果表明，具有线型结构的，高分子量的胶粘剂延伸性好，但拉伸强度稍低，聚氨酯胶粘剂可以用于高含水率木材的粘接。     

木材及木材胶粘剂防腐研发现状及其发展趋势

简要回顾了木材及木材胶粘剂防腐技术研究与开发的技术背景和国内外发展现状,着重总结了木材防腐剂及生物质基木材胶粘剂防腐剂的种类、特性和应用情况;对本领域今后的发展趋势作了初步探讨。     

我国人造板用胶粘剂发展浅议

胶粘剂在我国木材工业中占有举足轻重的作用，人造板行业胶粘剂的消耗量是十分可观的。针对当前我国胶粘剂行业存在的一些问题，提出了一些意见及建议，并对胶粘剂的发展趋势进行了探讨。     

多胺基聚合物改性室温固化型MUF树脂胶黏剂

为解决三聚氰胺-尿素-甲醛(MUF)树脂作为室外级结构集成材胶黏剂时存在的脆性大、易开裂的问题,得到韧性优秀且综合性能满足室外级结构集成材标准的室温固化型MUF树脂胶黏剂,本研究在MUF树脂合成中使用两种改性剂尿素-乙二胺(UE)、尿素-三(2-氨基乙基)胺(UD)分别替代部分三聚氰胺合成了 MUF-UE、MUF-UD...     

木结构用胶黏剂蠕变性能的评价

以红松、落叶松、杉木和桦木为试验材料,采用苯酚-间苯二酚-甲醛树脂胶(RPF)和酚醛树脂胶(PF)进行胶合,使用专用卡具,在长期、恒定的荷栽作用下,研究胶合试件在各种使用条件下的蠕变性能.结果表明:RPF树脂的抗蠕变性能优于PF树脂,落叶松、红松试件的抗蠕变性能优于桦木和杉木.     

不脱水脲醛树脂胶生产的新方法

用Ａ（助剂）分子链上的羟基与ＵＦ（脲醛树脂）的醛基缩合交链合成不需脱水的Ａ－ＵＦ胶的新方法。在终点投完物料后，添加０．４％Ａ直接合成Ａ－ＵＦ胶可用于三层、多层板的生产，且每吨Ａ－ＵＦ胶多获利４００余元。     

油酸对PF树脂胶粘剂的表面活化作用初探

在竹胶合板的胶膜纸生产中，油酸主要是作为一种脱膜剂使用的，而它对胶粘剂的表面活化作用却少有研究，以致在生产中，油酸的加量缺乏科学、合理的根据．油酸分子结构的两亲性，使它具备了作为表面活性剂的基本条件．这项研究通过不同的油酸加量，对胶粘剂的浸渍特性和胶膜纸上胶量所产生的不同影响，以及油酸和乙醇施加效果的比较，证明了油酸对ＰＦ树脂胶粘剂具有表面活化作用．根据试验结果分析，在ＰＦ树脂胶粘剂中加入０．４％～０．８％的油酸是比较适宜的，而加量为０．４％时，胶膜纸的上胶量达到最大值．此项研究仅对油酸对半醇溶性的ＰＦ树脂胶粘剂的表面活化作用作了初步探讨，其表面活化作用的机理尚待进一步研究．     

酚醛树脂胶粘剂的改性

介绍利用三聚氰胺,尿素,木质素,聚乙烯醇缩醛,间苯二酚等物质对酚醛树脂胶粘剂改性研究的最新进展。     

An experimental approach to determine pull-out strength of single and multiple axially loaded steel rods bonded in glulam parallel to the grain

ABSTRACT

A glued-in rods' connection is generally constituted by a group of steel bars bonded by an adhesive into timber elements. In the past, most of the research focused on single-rod connections, in order to exploit the maximum resistance of the connection without accounting for interaction among bars or splitting failure in the timber member due to close edge distances or spacing between bars. Such interaction problems arise when dealing with multiple rods, thus requiring specific investigation to fully understand the behavior of the connection as a whole and to determine its capacity. In both cases, existing test procedures determine bond strength in specific geometrical configuration. The paper aims to determine the pull-out strength of single and multiple axially loaded steel rods bonded in glulam parallel to the grain differentiating the adhesive failure from the other failure modes. After an initial review of typical applications and existing design procedures, test results on single rod with confined or unconfined test setup on single rod at different embedment depths are presented and discussed, indicating that the confinement has a negligible influence on the pull-out capacity. Subsequently, interaction between bars is investigated by a specific unconfined configuration. The accounted parameters are the embedment depth of the bars, the dimensions of the timber section, and the spacing between bars. Results are discussed and compared with three-dimensional numerical simulations. Both experimental and numerical results suggest that the critical value at which the transition from pull-out to timber-related failure is observed depends on the mechanical properties of the timber and on the properties of the adhesive, such that a single value of spacing should not be provided in design standard if the full capacity of the adhesive is to be exploited.     

脲醛树脂胶黏剂用添加剂的研究与应用进展

依据化学组成成分及降低游离甲醛含量的作用机理不同,将脲醛树脂胶黏剂用添加剂分为有机添加剂、纳米材料及无机矿物质添加剂,综述了脲醛树脂用添加剂的研究与应用进展。     

Fire resistance of sugi covering materials for structural steel

Glued laminated timbers (glulam) or planks 50mm thick were added to structural steel columns and beams as covering materials. The wood used in the glulam was sugi (Cryptomeria japonica D. Don) laminated with resorcinol resin adhesive between woods and epoxy resin adhesive between wood and steel. The 50mm thick planks of sugi around the steel were fixed with spirally threaded nails (screws), and 25mm long wood plugs were used to cover the tops of the nails. The 50mm thick glulam showed 1h of fire resistance. The temperatures of the flanges and webs of steel were 100°C at 1h and 200°C after 4h. The epoxy resin used to bond the wood and steel was an appropriate adhesive from a recycling perspective because it is easy to separate or peel from the steel.     

PMUF树脂胶黏剂的制备与性能

以尿素和三聚氰胺作为酚醛树脂改性单体制备苯酚-三聚氰胺-尿素-甲醛(PMUF)树脂胶黏剂,研究甲醛、苯酚、尿素、三聚氰胺及氢氧化钠用量对PMUF树脂胶黏剂性能的影响,并采用DSC和13C-NMR对其进行表征.结果表明:PMUF树脂游离甲醛含量低,能满足耐水、耐候性能要求较高的人造板产品的生产.当甲醛、苯酚、尿素、三聚氰胺、NaOH的摩尔比为3.1∶1∶0.7∶0.3∶0.5时胶黏剂性能最佳,其最佳固化温度为135.5℃.     

Mechanical behaviour of finger joints at elevated temperatures

Finger joints are commonly used to produce engineered wood products like glued laminated timber beams. Although comprehensive research has been conducted on the structural behaviour of finger joints at ambient temperature, there is very little information about the structural behaviour at elevated temperature. A comprehensive research project on the fire resistance of bonded timber elements is currently ongoing at the ETH Zurich. The aim of the research project is the development of simplified design models for the fire resistance of bonded structural timber elements taking into account the behaviour of the adhesive used at elevated temperature. The paper presents the results of a first series of tensile and bending tests on specimens with finger joints pre-heated in an oven. The tests were carried out with different adhesives that fulfil current approval criteria for the use in load-bearing timber components. The results showed substantial differences in temperature dependant strength reduction and failure between the different adhesives tested. Thus, the structural behaviour of finger joints at elevated temperature is strongly influenced by the behaviour of the adhesive used for bonding and may govern the fire design of engineered wood products like glued laminated timber beams.