三聚氰胺改性脲醛树脂胶粘剂对高密度纤维板性能的影响

探索了不同三聚氰胺用量改性对低物质的量比脲醛树脂胶粘剂的理化性质及其压制的高密度纤维板物理力学性能和防水性能的影响,并通过测定不同三聚氰胺用量改性的脲醛树脂胶粘剂的黏度、固含量、固化时间、游离甲醛含量、高密度纤维板的静曲强度、内结合强度和吸水厚度膨胀率,研究其性能.研究结果表明:当三聚氰胺用量由1％增加到10％时,脲醛...     

低甲醛释放木材胶粘剂研究进展

我国已成为世界人造板生产大国,木材胶粘剂年用量已超过400万t,其主要胶种为甲醛类合成树脂胶粘剂.本文评述了木材胶接用甲醛类合成树脂胶粘剂的开发研究、生产应用及发展,重点综述了低甲醛释放的脲醛树脂、三聚氰胺-尿素共缩合树脂和酚醛树脂胶粘剂的研究进展和开发应用情况,并对其发展趋势等进行了展望.     

强酸工艺制备低甲醛释放量的MUF胶粘剂

采用强酸工艺制备低F(甲醛)释放量的MUF[M(三聚氰胺)改性UF(脲醛树脂)]胶粘剂,并探讨了M掺量、固化剂类型及掺量对胶合板性能的影响。研究结果表明:当w(M)=4%(相对于F和U总质量而言)、w(硫酸铵)=2%(相对于UF的质量而言)时,MUF胶粘剂的综合性能相对最好;由该胶粘剂压制而成的3层胶合板的胶接强度(为1.5 MPa)相对最大,5层胶合板的F释放量(为0.33 mg/L)达到E0级Ⅱ类胶合板的标准要求。     

甲醛系木材胶粘剂

<正> 木材胶粘剂是一类籍助于表面附着将木材与木材或木材与其它材料胶合成一体的物质。通常包括酚醛树脂胶,脲醛树脂胶、三聚氰胺树脂胶、间苯二酚树脂胶、单宁胶、木素胶、多异氰酸酯胶、聚乙酸乙烯酯乳液以及植物蛋白胶、动物蛋白胶、淀粉胶等。其中最主要的是上列前三种,又合称三醛胶,它们都是由甲醛为主要原料合成的。这些胶粘剂,除了主体     

乙酰丙酮分光光度法测定纤维板甲醛释放量的不确定度评定

文章依据GB／T17657—1999对用于测定纤维板中有害物质甲醛的乙酰丙酮分光光度法的不确定度进行了研究。建立了数学模型,详细分析了测定过程中影响结果的各个分量,并对各不确定度分量进行评定,计算出了该法的合成不确定度和扩展不确定度。     

不含甲醛胶粘剂

日本DJK开发的不含甲醛胶粘剂，以低聚丙烯酸酯、聚醋酸乙烯酯乳液，过氧化氢固化剂CaCO3滤光剂等为制备原料，粘结强度、耐火性等质量性能与密胺粘合剂相近，且生产成本较低，可替代胶合板制造时使用的含甲醛的胶粘剂。     

低甲醛释放木材胶粘剂面临发展新机遇

通过对国家最近发布实施的室内装饰装修材料甲醛释放量强制标准的介绍，阐明了当前发展低甲醛释放木材胶粘剂正面临着良好的市场机遇。     

聚乙烯醇缩甲醛胶粘剂的改性

研究缩醛化反应中温度，酸度，原料配比和反应介质对产品性能的影响。同时通过多次实验确定了反应物的最低浓度，从而对降低生产成本，简化生产工艺有一定参考价值。     

国内低游离甲醛脲醛树脂胶粘剂研究进展

脲醛树脂胶粘剂是一种开发应用较早的热固性高分子胶粘剂。由于其制造工艺简单，原料廉价易得，初粘大，粘接强度高，无色透明，不污染木材等优点，广泛应用于木器加工、胶合板、刨花板、中密度纤维板、人造板材的生产及室内装修等行业，是目前粘合剂中产量最大的品种，占木材胶粘     

不含甲醛的胶乳胶粘剂

据市场咨询公司Frost＆Sullivan最近的一份报告称,广泛而深入的产品开发使欧洲热熔胶市场获益非浅。热熔胶作为“绿色”胶粘剂越来越受到人们的欢迎,在大多数胶粘剂的主要市场中增长迅速。     

脲醛树脂胶粘剂及其制品低毒化研究新进展

从脲醛树脂胶粘剂的配方改进、胶粘剂合成工艺改进、胶粘剂调胶及人造板热压工艺改进、甲醛吸附材料与人造板等的复合、人造板及其制品的后处理等几个方面,综述了近几年来脲醛树脂胶粘剂及其制品低毒化研究新进展。     

传统木材胶粘剂的改性研究进展

本文介绍了脲醛胶、酚醛胶、三聚氰胺一甲醛胶和白乳胶等传统胶种的低醛改性研究进展,并对木材胶粘剂的发展进行了展望。     

淀粉类胶粘剂的应用研究进展

综述了淀粉胶粘剂在胶合板工业、标签胶、瓦楞纸箱、建筑涂料和卷烟工业等领域中的应用研究进展。淀粉是一种可再生的天然高分子化合物,具有良好的粘接性能和成膜性能。淀粉胶粘剂具有环境友好、价格低廉和性能优良等特点,是一种发展潜力极大的胶粘剂。     

室内用水性涂料及水性胶粘剂中甲醛含量的检测研究

阐述了GB 18582-2001和GB 18583-2001标准中采用乙酰丙酮分光光度法测定游离甲醛含量的检测方法差异,主要包括乙酰丙酮的试剂要求、标准曲线的绘制、测定波长的选择和样品前处理等方面的差异。在详细分析两种检测结果差异原因的基础上,对两种测试标准进行改进,提出了适合水性涂料和水性胶粘剂中游离甲醛含量的测定方法;其线性范围为1～25μg,相关系数为0.9999;按照改进的测试方法,水性涂料和水性胶粘剂样品中甲醛含量的测定结果的相对标准偏差分别为1.9%和2.3%,平均回收率分别为94.2%和95.8%。     

低游离甲醛含量脲醛树脂胶粘剂的合成工艺研究

研究了在弱酸-弱碱-弱酸条件下,加入改性剂合成脲醛(UF)树脂胶的工艺过程。实验结果表明,甲醛与尿素的配比[即n(F)/n(U)比值]、体系pH值、尿素的加料方式和改性剂对UF树脂胶中游离甲醛的含量和胶合强度有很大的影响;当n(F)/n(U)=1.06、缩聚反应阶段体系的pH值为4.75～4.80、尿素分3批加入、反应温度为90℃、加入适量的聚乙烯醇(PVA)和三聚氰胺改性剂时,制得的UF树脂胶中游离甲醛的含量不大于0.10%(符合GB/T14 074.16-1993标准中的指标要求)、粘接强度为4.70 MPa且综合性能优良。     

低游离甲醛脲醛树脂胶粘剂的研制

尿醛树脂胶粘剂中的游离甲醛是人造板中主要的污染源。采用降低原料中甲醛和尿素摩尔比 ,分批加入尿素进行多次缩聚的方法降低游离甲醛的含量 ,并通过添加聚乙烯醇改性剂 ,使产品中游离甲醛的含量为 0 4 % ,产品陈放 1周后 ,游离甲醛降到 0 1%以下 ,完全可以满足环境保护的要求。该制备工艺简单 ,成本低     

Reduction of formaldehyde emission from plywood

The aim of this work is to evaluate performances of tannin-based resins designed as adhesive in the plywood production. For this purpose, a part of phenol formaldehyde (PF) and melamine formaldehyde (MF) in the classic adhesive formulation was replaced by tannin. The physical properties of the formulated resins (rheological characterization, etc.) were measured. In order to analyze the mechanical performance of tannin-based resins, plywood panels were produced and the mechanical properties including tensile strength wood failure and three-point bending strength were investigated. The performance of these panels is comparable to those of plywood panels made by commercial PF and MF. The results showed that the plywood panels bonded with tannin–PF (PFT) and tannin–MF (MFT) resins exhibited better mechanical properties in comparison to the plywood panels made of commercials PF and MF. The introduction of small properties of tannin in PF and MF resins contribute to the improvement of the water performance of these adhesives. The formaldehyde emission levels obtained from panels bonded with tannin-based resins were lower than those obtained from panels bonded with control PF and MF. Although there are no actual reaction at all between PF, MF, and tannin, addition of tannin significantly improves the water resistance of PF and MF resins. This is a novel finding that manifests the possibility of replacing a convention PF and MF resins by tannin. Modified adhesive is one of the goals in the plywood production without changing any of their production conditions with improvement to their overall properties.     

UV固化胶粘剂应用研究进展

论述了当前UV固化胶粘剂的应用现状,对UV固化胶粘剂配方中的主要原料预聚物、单体、光引发剂等的研究进展做了详细的阐述。     

Decreasing the formaldehyde concentration in indoor air by improving the adhesives used in engineered wood materials in Korean apartment buildings

Engineered wood materials, such as the urea-formaldehyde resin adhesives used to make plywood, are known to be one of the primary sources of formaldehyde emissions in the building industry. This study presents the results of measuring indoor formaldehyde concentrations in newly built apartment buildings at the pre-occupancy stage for more than three years. Formaldehyde emissions from engineered wood materials used in floorings and furniture were measured using the small chamber method. Indoor formaldehyde concentrations were measured by following, for the most part, the procedure proposed by the Korean Ministry of Environment. These measurements verified that improving the engineered wood materials used in the apartment buildings had an effect on lowering the formaldehyde concentrations. The results showed apparent decrease in formaldehyde concentrations when low-emission engineered wood materials were used. Regardless of the absolute decrease, seasonal fluctuations in formaldehyde concentrations were also observed. It was assumed that these fluctuations were caused by changes in the indoor air temperature and relative humidity. Nevertheless, it will be necessary to conduct further studies to identify the factors causing the weak correlation of formaldehyde concentrations with the indoor air temperature and relative humidity in each housing unit.     

人造板及其制品甲醛释放量限量与室内甲醛污染

本文通过对国家强制性标准GB18581-2001《人造板及其制品甲醛释放量限量》中实木复合地板甲醛释放量的分析,揭示了室内甲醛污染超标的原因,对此强制性标准提出了改进的意见.