共查询到18条相似文献,搜索用时 125 毫秒
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消除游离甲醛的新方法 总被引:4,自引:1,他引:3
消除游离甲醛的新方法刘光远生产家具所使用的胶合板和刨花板,一般都采用脲醛树脂作胶粘剂。这类胶合板和刨花板在制成家具后,常向周围空气中散发游离甲醛,刺激人的眼睛、皮肤,引起头痛等有害健康的反应。因此,希望有制止游离甲醛发生的方法。据报道,有一种消除游离... 相似文献
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研究了PVAc型固化剂与UF树脂热压胶合板的甲醛释放量和粘接强度.结果表明:PVAc型固化剂对热压胶合板的粘接强度改善不大;其中,PVAc-Ⅲ型固化剂与UF树脂热压胶合板的甲醛释放量最低,低于氯化铵与UF树脂热压胶合板的甲醛释放量1.21mg/L,而且均达到F2级胶合板的要求;尤其PVAc-Ⅲ-4型固化剂在m(Hardener):m(UF)=10:100时,其甲醛释放量最高为0.70mg/L,最低为0.41mg/L,平均为0.52mg/L,基本达到F1级胶合板的要求. 相似文献
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绪言胶合板生产大量使用脲醛树脂胶。但在制备脲醛树脂胶的过程中,必须考虑制造的困难和胶液的稳定性。因而通常把尿素与甲醛的克分子比,控制在1:2.0左右。根据过去所发表的报告,若采用高克分子比反应时,树脂的游离甲醛就多。同时由于存在-CO-、-CH_2OH等亲水性基团,使胶合板的湿状胶合强度下降,这也是造成脲醛树脂老化的原因。另外,树脂的游离甲醛含量高,制成的胶合板有较大的甲醛味, 相似文献
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国外人造板甲醛散发研究现状 总被引:16,自引:0,他引:16
本文根据大量的国外文献资料综述了人造板中游离甲醛产生的原因、甲醛散发量的定量测试方法、影响甲醛向外界散发的诸种因素以及降低人造板甲醛散发量的各种措施。 相似文献
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简述刨花板中甲醛释放的机理及检测 总被引:4,自引:0,他引:4
甲醛是甲醛系胶粘剂板制品在使用过程散发的一种污染环境的有害气体。根据国内外资料分析了我国花板甲醛释放的现状,介绍了脲醛树脂的水解和刨花板甲醛释放的机理,评述了8种检测方法和降低花板中甲醛释放量的具体措施。 相似文献
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Nuno A. Costa João Pereira João Ferra Paulo Cruz Jorge Martins Fernão D. Magalhães Adélio Mendes Luísa H. Carvalho 《Wood Science and Technology》2013,47(6):1261-1272
This work examines the performance of three formaldehyde scavengers in wood-based panels. Sodium metabisulfite, ammonium bisulfite and urea were applied in different physical forms during particleboard production, and the resulting physico-mechanical properties (internal bond strength, thickness swelling, density and moisture content) and formaldehyde emission levels were compared. Formaldehyde content was measured using the perforator method, and formaldehyde emission was evaluated both by desiccator and gas analysis methods. The chemical reactions involved in each formaldehyde scavenging process are proposed and discussed. The tested scavengers showed distinct performances under the different emission testing conditions, which were interpreted in terms of the stability of the chemical compounds formed upon formaldehyde capture. Sodium metabisulfite proved to be an excellent scavenger for all formaldehyde methods allowing the production of particleboard panels with zero formaldehyde emission. 相似文献
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人造板中的甲醛释放及其检测方法 总被引:7,自引:1,他引:7
对人造板产品中的游离甲醛问题列出了近年来抽查检验的结果及其统计分析,介绍了甲醛释放机理和6种检测方法及降低人造板中游离甲醛的具体措施。 相似文献
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采用1 m3气候箱法测试2种浸渍胶膜纸饰面人造板甲醛释放规律以及不同处理条件对板材甲醛释放浓度的影响。结果表明,热压工艺、基材结构可能是影响甲醛释放周期的关键因素,2种饰面人造板的平衡周期基本相同;封边处理可有效降低甲醛含量得释放;温度和相对湿度与板材甲醛释放量呈正相关,空气交换率与板材甲醛释放量呈负相关。 相似文献
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龚铮午 《中南林业科技大学学报(自然科学版)》1997,(2)
分析了人造板释放甲醛的来源,述评了当前降低脲醛树脂甲醛释放量的措施,提出了多元改性工艺,采用该工艺生产脲醛树脂,甲醛释放量小,不需脱水操作.成本略有降低. 相似文献
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Preparation and properties of waste tea leaves particleboard 总被引:4,自引:0,他引:4
Shi Jin-shu Li Jian-zhang Fan Yong-ming Ma Hong-xia 《中国林学(英文版)》2006,8(1):41-45
Urea-formaldehyde (UF) adhesive is the main source of formaldehyde emission from UF-bonded boards. The components in waste tea leaves can react with formaldehyde to serve as a raw material in the production of low formaldehyde emission boards. In our study, waste tea leaves and UF adhesive were employed in the preparation of waste tea leaves particleboard (WTLB). An orthogonal experimental method was applied to investigate the effects of process parameters on formaldehyde emission and mechanical properties of WTLB. The results indicated that: 1) waste tea leaves had the ability to abate formaldehyde emission from boards; and 2) density of the WTLB was a significant factor affecting its modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB). 相似文献