不同干燥温度下纤维VOCs组成分析及气味评价

Analysis of VOCs Composition and Odor Evaluation of Fibers at Different Drying Temperatures

选用纤维板生产线热磨工序纤维,经不同温度干燥至含水率(9±0.5)%。采用顶空固相微萃取(HS-SPME)结合气相色谱-质谱(GC-MS)对不同干燥温度纤维释放的挥发性有机化合物(VOCs)组成进行定性定量分析,同时人工嗅闻测试纤维的气味等级,研究干燥温度对纤维VOCs组成和气味等级的影响。结果表明,随着干燥温度的升高,纤维VOCs组分释放量和气味等级均呈下降趋势,两者下降幅度表现为VOCs组分释放量大于气味等级。试验纤维VOCs组分包括萜烯类、酸类、醛酮类和酯类等,其中40℃干燥纤维以萜烯类和酸类为主,120~180℃干燥纤维均以萜烯类为主;酸类化合物在120℃干燥时大幅下降,160℃时完全消失,说明160℃干燥温度能完全消除酸类物质对纤维气味的影响。生产低气味纤维板时,原料中不应包含气味嗅阈值很低的VOCs组分,建议在设备安全范围内,适当提高干燥温度。

Fibers from the defibrator process were dried to a moisture content of(9±0.5)%at various temperatures.The effects of drying temperature on VOCs composition and odor grade were analyzed using headspace solid-phase microextraction(HS-SPME)combined with gas chromatography-mass spectrometry(GC-MS).The results indicated that higher drying temperatures reduced both VOCs emissions and odor grades,with VOCs reduction outpacing odor grade decline.Major VOCs included terpenes,acids,aldoketones,and esters.At 40℃,terpenes and acids were predominant,whereas at 120~180℃,terpenes dominated.Acid compounds significantly decreased at 120℃ and were completely absent at 160℃,suggesting that drying at 160℃ can eliminate acid-related odors.For low-odor fiberboard production,raw materials should be free of VOCs with low odor thresholds,and drying temperatures should be optimized within equipment safety limits.