干燥器法测定人造板甲醛释放量的不确定度评价

根据GB/T 17657-2013《人造板及饰面人造板理化性能试验方法》中干燥器法测定甲醛释放量,对人造板中甲醛释放量进行测定,并根据JJF 1059-2012《测量不确定的评定与表示》提出了干燥器法测定甲醛释放量的不确定度的评定方法,对甲醛释放量的不确定度进行分析和评价,确定了干燥器法测定人造板中甲醛释放量的测定结果的不确定度。     

人造板家具甲醛释放量检测干燥器法研究与分析

实验通过干燥器法对不同使用功能的人造板类家具的甲醛释放情况进行了检测,以确定不同种类人造板类家具甲醛释放量之间的关系。干燥器实验结果显示,当人造板家具生产所使用板材相同的情况下,干燥器法检测的数值基本上相同,从而得出结论,干燥器法不能反映不同种类家具甲醛释放状况。同时,实验结果还说明了GB18584-2001《室内装饰装修材料木家具中有害物质限量》还存在很多需要进一步完善和改进的地方。     

人造板甲醛释放量检测方法探究

因甲醛的危害程度较大,因此针对人造板中甲醛的释放量的检测方法越来越受到社会各界关注。对人造板甲醛释放量的几种国内外常见的检测方法进行研究,如干燥器法、气候箱法、穿孔萃取法,提高检测效率和检测准确性。     

酚醛泡沫夹芯板甲醛释放与检测初步探讨

对酚醛泡沫夹芯板中甲醛的来源、释放的影响因素以及控制方法进行了初步探讨。介绍了国内外关于人造板甲醛释放量的相关规定。根据材料的特点及甲醛释放情况,采用40L干燥器法进行了甲醛检测,并进行了讨论。结果表明:与仲裁检测法———1m3气候箱法相比较,该检测方法的结果偏差很小,当取置信水平为0.95时,检测结果的变异系数均小于10%,重现性好。     

浅析国内外人造板甲醛释放量干燥器法的异同

现今,我国人造板生产量已成为世界第一人造板生产大国。人造板是利用木材和胶粘剂为主要原料,通过一定的生产工艺加工而成的不同种类的板材,现代建筑家庭装修中经常会使用大量的人造板,但是人造板中往往含有甲醛,甲醛对人体健康的影响日益引起国家和人们的关注,而甲醛释放量作为人造板一项重要评价指标,文章针对当前我国、美国、日本等国内外广泛使用的甲醛释放量干燥器法测试方法进行分析。     

气候箱法测定人造板甲醛释放量不确定度评定

采用1 m3气候箱法对人造板进行甲醛释放量测定,对测定过程的不确定度进行量化和评定,结果表明,引入不确定度的因素按引入不确定度大小排序依次为:采气过程,标准曲线绘制过程,标准物质,气候箱内部环境,重复性测定过程,分光光度计;其余影响因素对不确定度贡献较小。     

人造板家具中甲醛释放量检测方法探讨

随着近些年科学技术的发展,室内使用人造板类装饰装修材料数量明显增加,因此使用人造板制作的家具受到了广大消费者的喜爱,有着非常好的市场销售情况。然而,人造板家具在当今世界的广泛使用也导致了另一重大的环境问题--室内污染。大量的人造板家具在室内使用,产生的甲醛释放源大幅度增加,造成室内空气污染。而人造板家具则是引起室内甲醛浓度超标的重要释放源,从而使得人造板家具的甲醛释放量越来越受到人们的关注。本文系统化的分析了影响人造板家具中的甲醛释放量检测结果的各项因素,并对甲醛的收集、甲醛含量的定量操作这两个关键操作步骤进行了详细阐述,从而对人造板的甲醛释放量的检测方法有更深入的了解。     

科技木皮甲醛检测方法的研究

科技木皮中含有甲醛,可采用干燥器法收集科技木皮的甲醛,通过分光光度计法测定其甲醛释放量。分析多组实验数据确定样品数量,测试时间和测试温度,从而寻找一种较好的科技木皮的甲醛检测方法。     

人造板甲醛释放量检测方法的分析

人造板材中甲醛的释放严重影响着人体健康,因此研究板材甲醛释放的检测方法可以减少室内污染、保障人体健康。系统地介绍了人造板甲醛释放量检测的几种常用方法,分析了影响检测结果的主要因素,对规范实验室实验操作、提升检测水平具有指导作用。     

建筑装修材料人造板甲醛释放量研究

实验通过气候箱对不同厂家生产的人造板甲醛释放情况进行了检测,以研究气候箱内甲醛浓度随时间的变化规律。实验结果显示,不同厂家生产的人造板甲醛释放量差异较大。随时间推移,气候箱内甲醛浓度在不断减小,当达到某一时间后,甲醛浓度变化较小,基本保持稳定,此时认为甲醛释放量达到稳定。     

干燥器法中甲醛释放，扩散和吸收的规律

以家具产品质量标准中检测甲醛释放量的干燥器法为研究对象,分别对甲醛从板中释放,甲醛在空气中扩散和甲醛被水吸收三个过程进行深入研究。根据经典的气体传质理论,我们分别介绍了这三个过程中甲醛气体传质的数学模型。通过数学关系的分析,我们发现板材本身,环境温度和湿度,甲醛在空气中扩散效率和被水吸收程度对检测结果有不同程度的影响,针对这些影响,我们从原理上提出了初步的改进建议。     

改性三聚氰胺树脂及其饰面刨花板的制备与研究

为解决人造板甲醛含量普遍超标的现状,文章采用纳米二氧化钛(TiO2)/纳米蒙脱土(MMT)混合液与三聚氰胺树脂复合,并利用改性的三聚氰胺树脂制备三聚氰胺饰面刨花板。再分别利用单组份的纳米粒子改性三聚氰胺树脂,利用这两种改性树脂及未改性的树脂制备三聚氰胺饰面刨花板,将这三组板材设为对照组。参照国家标准《人造板及饰面人造板理化性能试验方法》(GB/T 17657—1999),利用紫外光分光光度计测量板材中的甲醛含量。结果表明,纳米TiO2/MMT改性的三聚氰胺饰面刨花板的甲醛含量最低,仅为0.427mg?L-1,明显符合国家室内使用标准,达到欧洲E0级标准(≤0.5mg?L-1)。且这类板材成本低廉、制备工艺简单,有利于大规模生产,在环保型人造板的研发及生产等领域具有巨大的应用潜力。     

低甲醛释放量人造板用改性脲醛树脂制备及应用研究

为了降低脲醛树脂的游离甲醛含量及其胶接制品的甲醛释放量,本研究在脲醛树脂合成过程中加入改性剂代替部分甲醛,通过尿素-甲醛-改性剂发生共缩聚反应,合成了改性脲醛树脂。研究了改性剂取代甲醛的摩尔比对改性脲醛树脂固化速度、游离甲醛含量的影响,以及在不同的热压条件下,对胶接胶合板的胶合强度和甲醛释放量的影响。研究结果表明,改性剂的加入不仅能有效降低改性脲醛树脂的游离甲醛含量及其胶合板的甲醛释放量,还能提高胶合板的胶合强度和耐水性。     

木质素改性酚醛树脂的研究进展

人造板工业用的酚醛树脂胶,虽然粘接性能好,但在制造和使用的过程中都会释放出污染物甲醛,而木质素分子中有酚羟基和醛基,使用木质素,既可改善胶粘剂的性质,又可节约苯酚的用量,降低甲醛释放量,达到废物利用与保护环境的目的本文综述了木质素磺酸盐、碱木质素、甘蔗渣木质素、酶解木质素等代替部分苯酚应用于环保树脂胶的制备工艺及研究发展现状,并对其发展前景作了展望     

Alternative to latent catalysts for curing UF resins used in the production of low formaldehyde emission wood-based panels

This paper studies alternative catalysts to ammonium sulfate for curing urea-formaldehyde (UF) resins. When using a latent catalyst like ammonium sulfate, hexamine is formed as by-product of curing reaction. It is believed that hexamine hydrolysis may contribute to formaldehyde release during the life-time of wood-based panels produced with UF resins. Orthophosphoric acid, on the other hand, catalyzes resin cure without by-product formation and was compared to ammonium sulfate. The pot-life of adhesives with both catalysts was evaluated at 40 °C with a Brookfield rheometer. Mechanical resistance tests performed with ABES (Automated Bonding Evaluation System) showed that orthophosphoric acid effectively catalyzes UF resin cure. Particleboards were produced using both catalysts and the most important properties evaluated, according to European Standards: formaldehyde content, internal bond, moisture content, thickness swelling and density. Particleboards cured with orthophosphoric acid and stored under forceful conditions of humidity and temperature presented similar internal bond and lower formaldehyde content than those produced with ammonium sulfate.     

稀土La2O3改性脲醛树脂的黏度特性研究

脲醛树脂(UF树脂)胶黏剂具有胶合强度高、制作简单、成本低廉、原料来源丰富等一系列特点,成为我国人造板生产的主要胶种,是市场上需求量最大的胶黏剂之一。但由于在固化时会放出刺激性的甲醛,游离甲醛高,在使用时严重危害人的健康。近年来,随着人们环保意识的提高,生产和使用低毒UF树脂胶势在必行。本文介绍了稀土氧化镧对脲醛树脂的改性过程并对改性后脲醛树脂胶的各项性能进行了测试。本实验通过在不同反应阶段加入稀土氧化镧,分别探讨它们对脲醛树脂胶黏剂性能影响。实验表明:在脲醛树脂胶中加入稀土氧化镧可以增加黏度、固化时间、固含量,并可以减少游离甲醛释放量。     

Improving the properties of ionic liquid-treated lignin-urea-formaldehyde resins by a small addition of isocyanate for wood adhesive

The aim of this research was to investigate the effect of polymeric 4, 4 diphenyl methane diisocyanate (pMDI) on the physical and mechanical properties of plywood panels bonded with an ionic liquid (IL)-treated lignin-urea-formaldehyde resin. Soda lignin modified by 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) IL was added to a urea formaldehyde (UF) resin during resin synthesis to prepare a lignin-urea-formaldehyde (LUF) resin. pMDI at various contents (2, 4, and 6% on resin solids) was then added to prepare a LUF resin. The thermal and physicochemical properties of the resins prepared as well as the water absorption, shear strength, and formaldehyde emission of the plywood panels bonded with them were measured according to standard methods. DSC analysis indicated that the addition of pMDI decreases the gel onset and curing temperatures of the LUF resin. According to the results obtained, the addition of pMDI significantly increased the viscosity and solid content and accelerated the gelation time of LUF resins. Based on the findings of this research, the addition of pMDI dramatically improves the performance of LUF resins as a new adhesive for wood-based panels. The LUF resins with isocyanate added yielded panels presenting lower formaldehyde emission and lower water absorption content when compared to those bonded with the control LUF resins. Greater dry and wet shear strength can be obtained by a small addition of pMDI to LUF resins.     

Decreasing formaldehyde emission from medium density fiberboard panels produced by adding different amine compounds to urea formaldehyde resin

In this study, medium density fiberboard panels were produced by adding different ratios of some amine compounds to urea formaldehyde resin, which had 1:1.17 mol ratios. The formaldehyde contents, physical, and mechanical properties of medium density fiberboard panels were determined according to EN standard methods.In this study, it was determined that the formaldehyde emission emitted from medium density fiberboard panels decreased by adding urea, propylamine, methylamine, ethylamine, and cyclopentylamine solution. It was found that the water absorption and thickness swelling values increased slightly; however, the internal bond strength, modulus of rupture, and modulus of elasticity of medium density fiberboard panels also increased substantially, but these properties of medium density fiberboard panels decreased by adding higher ratios of urea solution. It was found that the formaldehyde emission of medium density fiberboard panels decreased 16.5% by using a 16% rate of urea formaldehyde resin and 0.8% rate of urea and ethylamine solution. These decreases were determined as 57% for cyclopentylamine solution addition, 41% for propylamine solution addition, and 48% for methylamine solution addition.     

Surface coating performance of TiO<Subscript>2</Subscript> nanoparticle-modified veneered panels and their influence on formaldehyde emission

The physical and mechanical properties of wood and wood-based panels can be effectively improved by modification with nanoparticles. This paper focuses on effects of modifying veneer with titanium dioxide (TiO₂) nanoparticles on the performance of a waterborne coating and formaldehyde emission. Commercial waterborne varnish was used to apply a surface finish on the modified veneered panels. Changes caused by TiO₂ nanoparticle treatment that could affect the finishing performance were measured. The results showed slight increases in the weight and contact angle of the veneers treated with TiO₂ nanoparticles, whereas the modified veneered panels after surface finishing presented improved hardness at high nanoparticle loadings. Modification of the veneers by nanoparticles had a minor negative influence on the coating glossiness and adhesion due to a blocking effect between the coating film and the modified veneers. Formaldehyde emissions were considerably reduced due to degradation by the TiO₂ particles under UV-light irritation.     

Graphene oxide a promising formaldehyde scavenger of phenolic resin-bonded plywood: From elaboration to evaluation

A long-standing manufactured and most frequently used resin is phenol-formaldehyde resin, which has currently reached new horizons by incorporating nano reinforcements, even at lower loadings. Nanostructured materials, particularly graphene, have gained considerable interest in recent years because of their fascinating characteristics. Herein, this study explores for the first time the potential of prepared graphene oxide (GnO) as an effective formaldehyde scavenger in the development of plywood panels containing PF resins. The addition of 1% of GnO to the system resulted in a significant improvements in the mechanical properties by more than 45% in the shear strength (SS), 35% in modulus of elasticity, and 25% in modulus of rupture when compared with the reference panel. While the moisture resistance of panels were found to remarkably enhanced showing an increase in SS by 25% and 37% After 24 h in cold water (20°C) and 12 h of immersion in boiling water, respectively. The results also demonstrated that GnO exhibited exceptional formaldehyde capture efficiency, surpassing 60% reduction compared with the control. This innovative research not only unveils the novel potential of GnO in improving the performance of PF resins but also ushers in a new way of developing eco-friendly wood-based materials.