北京市消费者协会对16种强化复合木地板甲醛气体释放量预评价比较试验结果

目前复合木地板使用的胶粘剂仍以脲醛树脂为主,地板中残留未参与反应的甲醛会以气态形式向周围环境中逐渐释放。往往会危害身体健康。北京市消费者协会为了指导消费者正确选购复合木地板,进行了甲醛气体释放量的预评价比较试验。试验样品是由消协工作人员以普通消费者的身份在北京主要建材市场购买,测试委托北京市劳动保护科学研究所进行,试验结果仅对样品负责。日前,向北京公布了试验结果。甲醛气体释放质量系指在常温25℃时单位面积的复合木地板释放出的甲醛气体的质量。经测试16种强化复合地板甲醛气体释放量均在0.56～0.226mg/m2之间;预…     

不同检测方法对密度板甲醛释放量检测结果的影响

为了验证不同的检测方法(穿孔萃取法和干燥器法)对人造板甲醛释放量检测结果的影响,试验选取甲醛释放量不同的两种密度板进行检测。结果显示,两种试验方法测量的甲醛释放量对应的技术指标值,其检测结论在一定范围内是一致的,超出此范围可能会得出不同的结论。     

来稿精粹

干燥器法检测胶合板甲醛释放量的有关问题(1)对于送检胶合板样品的规格和要求,各有关标准包括《民用建筑工程室内环境污染控制规范》GB50325-2001、《室内装饰装修材料人造板及其制品中甲醛释放量限量》GB18580-2001、《人造板及饰面人造板理化性能试验方法》GB/T17657-1999均未明确说明,仅说明了试验样品的规格要求。为使检测结果更能代表进样材料的真实情况,送检样品不应切成小块的试验样品,其大小应满足切掉四周边沿后足够制作干燥器法的试验所用。取样后立即用不含甲醛的包装材料将样品密封。试验人员制作完试验样品后应及时进行甲醛…     

有关甲醛含量的国家标准

目前国家发布的与室内环境有关的甲醛的检测标准主要有:⑴中华人民共和国国家标准《居室空气中甲醛的卫生标准》规定:居室空气中甲醛的最高允许浓度为0.08毫克/立方米。⑵中华人民共和国国家标准《实木复合地板》规定:A类实木复合地板甲醛释放量小于和等于9毫克/100克;B类实木复合地板甲醛释放量等于9毫克～40毫克/100克。⑶《国家环境标志产品技术要求—人造木质板材》规定:人造板材中甲醛释放量应小于0.20毫克/立方米;木地板中甲醛释放量应小于0.12毫克/立方米。有关甲醛含量的国家标准     

绝热用玻璃棉及其制品甲醛释放量1立方米气候箱法检出限评定

绝热用玻璃棉及其制品由于其制造工艺,易造成甲醛的少量残留,而在使用1立方米气候箱法检测甲醛释放量的过程中,由于甲醛含量低,造成检测结果较真实情况偏低,甚至未检出,影响了检测的准确性。本文根据实验室条件、环境、实验用水、相关药品与试剂及仪器设备,计算1立方米气候箱法测定绝热用玻璃棉及其制品甲醛释放量的检出限,以期对检测工作有所帮助。     

不同温度下细木工板甲醛释放量的模拟研究

为了验证不同温度对细木工板甲醛释放量检测结果是否有直接影响,本文分别用同一品牌同一批次的细木工板为研究对象,按照干燥器法测定细木工板的甲醛释放量,在不同温度条件下对细木工板的甲醛释放量进行研究和测定,从而为人造板材甲醛释放量的测定以及室内甲醛污染的防治提供实验数据。     

干燥器法人造板甲醛释放量检出限的测定

甲醛是具有刺激性气味的无色气体,对人的眼睛、鼻腔、咽喉等部位均有明显的刺激作用,此外还具有普遍的致敏及致癌特征,是严重污染环境的污染物和严重危害人体健康的潜在化学危险物。人造板因其制造工艺,甲醛单体及其低聚物会有一定量的残留,而在人造板甲醛释放量检测过程中,因残留量较少有时检测数值偏低甚至为零,这显然与实际情况不符,因此需要在干燥器法人造板甲醛释放量检测过程中计算出方法检出限,以保证实验数据的真实有效。检出限值与实验室用水、试剂、实验室环境条件和人员的操作水平密切相关。本文讨论了用干燥器法测定甲醛释放量的方法检出限值,以帮助生产企业控制自己的产品质量,检查缺陷,弥补泄漏,提高实际产品的生产质量,同时希望能有助于同行开展相应的检测工作。     

中密度纤维板游离甲醛的散发及测定

甲醛释放量过高，是影响我国中密度纤维板产品质量的重要因素。本文根据国内外资料，介绍了中密度纤维板产品中有关甲醛释放的原因，法规与计量单位，测定甲醛释放量的方法和降低甲醛释放量的措施。     

不同等级细木工板对甲醛释放量检测结果的影响

为了验证不同等级细木工板板材对甲醛释放量检测结果的影响,取高、中、低三档细木工板,按《室内装饰装修材料人造板及其制品中甲醛释放限量》(GB 18580-2001)的要求,检测同一块细木工板的不同位置的甲醛释放量。结果显示,细木工板的优劣对甲醛释放量检测结果的判定有一定的影响。     

正确检测饰面人造板的甲醛释放量

饰面人造板在近年得到大力的推行,但在对其甲醛释放量检测方法的判断上,现在出现了一些错误的做法,笔者就专门针对饰面人造板甲醛释放量检测中出现两种做法进行讨论和分析.     

基于气候箱的中密度纤维板甲醛散发特征研究

采用气候箱模拟室内环境,测试了中密度纤维板(MDF)的甲醛散发量,分析了MDF厚度和封闭方式及气候箱温度、相对湿度和空气交换率对MDF甲醛散发量的影响,探讨了MDF甲醛散发机理.结果表明:MDF甲醛散发的主要通道是板材四周端面,其甲醛初始散发量是板材上、下表面甲醛初始散发量的1倍以上;MDF越薄,其甲醛散发量越大;随着气候箱温度和相对湿度的升高,MDF甲醛散发量增大;随气候箱空气交换率提高,MDF甲醛散发量降低.MDF甲醛散发过程可分为3个阶段,即短期快速散发阶段、中期缓慢散发阶段和长期稳定散发阶段.     

TVOC and formaldehyde emission behaviors from flooring materials bonded with environmental-friendly MF/PVAc hybrid resins

Polyvinyl acetate (PVAc) was added as a replacement for melamine-formaldehyde (MF) resin in the formaldehyde-based resin system to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. A variety of techniques, including 20-l chamber, field and laboratory emission cell (FLEC), VOC analyzer and standard formaldehyde emission test (desiccator method), were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with five different MF resin and PVAc blends at MF/PVAc ratios of 100:0, 70:30, 50:50, 30:70 and 0:100. Although urea-formaldehyde (UF) resin had the highest formaldehyde emission, the emission as determined by desiccator method was reduced by exchanging with MF resin. Furthermore, the formaldehyde emission level was decreased with increasing addition of PVAc as the replacement for MF resin. UF resin in the case of beech was over 5.0 mg/l, which exceeded E2 (1.5-5.0 mg/l) grade. However, MF30:PVAc70 was 相似文献   

木制家具甲醛检测标准研究与应用探讨

为科学指导室内装饰装修选材,以实现对室内装饰装修项目完工后室内环境中甲醛有效的控制,本文重点研究了国内外应用气候舱法测量木质家具中甲醛释放量的相关检测标准,并在此基础上探讨了影响甲醛释放的相关环境因素,从而得出根据小型气候舱测试木制家具系统各组件甲醛释放量结果推算木制家具早期投入使用时室内甲醛浓度参数的计算模型,为木制家具甲醛测试方法的应用与工程选材提供了参考。     

刨花板端面和平面甲醛散发的分布

通过实验分析了刨花板端面和平面甲醛散发的分布特征，给出了数学模型。作者认为，注意甲醛散发试件的取样位置是必要的。     

Formaldehyde as a basis for residential ventilation rates

Traditionally, houses in the US have been ventilated by passive infiltration in combination with active window opening. However in recent years, the construction quality of residential building envelopes has been improved to reduce infiltration, and the use of windows for ventilation also may have decreased due to a number of factors. Thus, there has been increased interest in engineered ventilation systems for residences. The amount of ventilation provided by an engineered system should be set to protect occupants from unhealthy or objectionable exposures to indoor pollutants, while minimizing energy costs for conditioning incoming air. Determining the correct ventilation rate is a complex task, as there are numerous pollutants of potential concern, each having poorly characterized emission rates, and poorly defined acceptable levels of exposure. One ubiquitous pollutant in residences is formaldehyde. The sources of formaldehyde in new houses are reasonably understood, and there is a large body of literature on human health effects. This report examines the use of formaldehyde as a means of determining ventilation rates and uses existing data on emission rates of formaldehyde in new houses to derive recommended levels. Based on current, widely accepted concentration guidelines for formaldehyde, the minimum and guideline ventilation rates for most new houses are 0.28 and 0.5 air changes per hour, respectively.     

Evaluation of three test methods in determination of formaldehyde emission from particleboard bonded with different mole ratio in the urea–formaldehyde resin

The use of urea–formaldehyde (UF) resins with lower contents of free formaldehyde in the board industry has led to products with very low emissions of formaldehyde. In this study, a detailed account is given of how UF resins with different mole ratios of formaldehyde to urea within the range of 0.97–1.27 influence the formaldehyde emission. In order to evaluate simpler laboratory methods for determining the formaldehyde emission from particleboard, the desiccator (JIS A 5908, 2003) and the EN 120 (European Standard, 1991) have been compared with the 1 m³ chamber method SS 270236 (Swedish Standard of determining formaldehyde emission with chamber test, 1988). Good relationships were obtained between the methods studied with correlation coefficients of >0.9. The value of formaldehyde emission decreased linearly with the mole ratio of formaldehyde to urea down to 1.05 where the effect smoothed out. The effect on the formaldehyde emission of temperature and storage time for tested boards also was studied. The heat treatment lowered the perforator value with resins that had mole ratios equal to or higher than 1.15, at the two lowest mole ratios 0.97 and 1.01, there was a tendency for the heat treatment to increase the perforator value. After the boards were stored for 6 months at 23 °C and 50% RH, the perforator values were unchanged or negligibly changed with the lower mole ratios and there was a more pronounced change with a higher mole ratio of 1.27.     

无醛板与净醛板在实际房间中的环保性能

市场上的无醛板和净醛板两种板材均以实验室检测报告为依据，称甲醛散发较低，且后者还称可净化室内空气中的甲醛。本研究选取实际房间作为研究场所，测试无醛板和净醛板的甲醛散发量及净醛板的甲醛净化能力。结果显示，两种板材散发的甲醛均较少，但未检测到净醛板在实际房间中的甲醛净化效果。     

Impact of temperature on the initial emittable concentration of formaldehyde in building materials: experimental observation

The initial emittable concentration of volatile organic compounds (VOC) is a key parameter not only in evaluating the 'green' degree of building materials but also in modeling their emission characteristics. Although the impact of temperature on initial emittable concentration is important, it has not been reported in the literature. Using the multi-emission/flush regression method we developed, the impact of temperature on the initial emittable concentration of formaldehyde in medium density board has been experimentally studied. It is observed that the initial emittable concentration increases significantly with increasing temperature. When the temperature rises by 25.4°C, it increases by about 507%. However, the initial emittable concentration at room temperature is far less than the value measured by the perforator method recommended by the Chinese National Standard GB/T 17657-1999, which measures the total concentration of formaldehyde in medium density board. This means most of formaldehyde in the building material cannot emit out at room temperature. The results will be very helpful in estimating the emission characteristics of building materials at different temperatures as well as for developing green building materials. PRACTICAL IMPLICATIONS: Knowledge of initial emittable concentration is important for VOC emission prediction. According to our experimental study, the initial emittable concentration is heavily dependent on temperature, and this factor should be considered in dealing with heating or cooling process of building materials. The significant difference between the initial emittable concentration and total concentration suggests that the total concentration seems not appropriate for judging the pollution level of building materials.     

Biological Determination of Emission of Irritants from Paint and Lacquer

Initation of the eyes and the upper respiratory tract (sensory irritation) in man due to the emission of vapours and gases from water-based indoor paints has been estimated from their ability to decrease the respiratory rate in mice (ASTM: E981-84, slightly modified). An acid-curing lacquer, known to give rise to sensory irritation during occupational exposure, was used as the positive control. In the bioassay the and-curing lacquer also gave rise to a pronounced sensory irritation, confirming that the ASTM method was applicable. Furthermore, the emission of formaldehyde, bases and acids was determined. The irritation within the first week was mainly due to the emission of organic solvents, but formaldehyde also played a role. Later the sensory irritation effect was caused mainly by the emission of formaldehyde. This indicates that the method revealed the different emission phases. None of the water-based paints (3 latex wall paints, 1 silicate paint and 1 distemper) gave rise to a biologically significant irritation effect. Nor did the water-based products emit formaldehyde or acids. However, varying degrees of emission of ammonia were observed. Taking into account the biological detection limits, no significant degree of sensory irritation can be expected in man 1-2 weeks after indoor painting with the tested water-based products.