硝基清漆膜厚度对硝基清漆VOCs释放的影响

Effect of paint film thickness on VOCs emission from nitrocellulose varnish

利用自制的小型环境测试舱,研究了硝基清漆膜厚度对挥发性有机物(VOCs)释放的影响.漆膜厚度分别为296,508,715,799,960μm,测试条件为:温度为25.0℃,相对湿度为23.9%,空气流量为0.75m3/h,空气流速为3.4cm/s,支持板为不锈钢盘.采用真空采样罐采集舱出口空气,用气相色谱(GC-FID)分析测试.确定了5种主要VOCs(甲基环乙烷、甲苯、乙苯、间/对二甲苯和邻二甲苯)的浓度,并以一阶衰减模型对浓度进行模拟计算得到释放速率.结果表明,漆膜厚度并不影响VOCs的峰值浓度和初始释放速率,但漆膜越厚,VOCs的浓度衰减越慢,衰减速率越小。

The effect of the paint film thickness on the emission of volatile organic compounds （VOCs） from nitrocellulose varnishes was studied in the self-made small-scale dynamic environmental test chamber. The film thickness range was 296, 508, 715, 799 and 960gm in turn. In all the experiments the temperature, the relative humidity, the airflow rate and the airflow velocity were set to 25.0℃, 23.9%, 0.75m3/h and 3.4cm/s respectively. The substrate used was stainless steel plate. The air samples were collected using vacuum canisters at the outlet of the chamber. And the sample was analyzed by the gas chromatography （GC-FID） shortly. The concentrations of five major VOCs including methyl cyclohexane, toluene, ethylbenzene, p, x-xylene and o-xylene were determined. The emission rates of VOCs were calculated through the first-order decay model simulation. Results showed that the peak concentration and the initial emission rate were independent of the paint film thickness. However, the thicker the paint film was, the slower the VOCs concentration decayed. And so was the decay rate.