摘要:
该文采用干燥器法和穿孔法,分析了板材含水率变化对干燥器值和穿孔值的影响规律.结果表明,含水率对不同种类板材干燥器值的影响有较大不同,但干燥器法受试件含水率影响较小.对于刨花板和中密度纤维板,含水率的影响规律基本相同,即含水率从4%到9%,干燥器值随含水率增加呈对数增加;含水率从9%到13%,干燥器值比较稳定;而含水率从13%到15%,中纤板的干燥器值迅速下降.对于饰面中纤板,干燥器值与含水率呈现较好的二次函数关系.对于细木工板和胶合板,干燥器值随含水率增加呈指数曲线增加.若采用干燥器法检测甲醛释放量,检测应对板材进行含水率平衡处理,即中纤板和刨花板的含水率约9%～13%,饰面中纤板含水率约7%～9%.含水率对穿孔值的影响非常显著,含水率从3%到16%,穿孔值随含水率增大呈线性增加;在含水率为3%～13%的范围内,穿孔值采用含水率修正系数是有效的.
Abstract:
The influence of moisture content (MC) on formaldehyde emission from wood-based panel was analyzed by using desiccator and perforator methods.The results show that the effects of MC on desiccator values for different kinds of panels are obviously different,but the influence of MC by the desiccator method is not obvious.For particleboard and MDF:if MC is within 4%-9%,formaldehyde emission gradually increases logarithmically with MC increasing;if MC within 9%-13%,formaldehyde emission almost keeps constantly; if MC within 13%-15%,formaldehyde emission decreases swiftly with MC increasing.On the other hand,for decorative MDF (DMDF),a conic relationship exists between formaldehyde emission and MC.For block board and plywood,when moisture content is within 6%-14%,formaldehyde emission increases linearly with MC increasing.If formaldehyde is measured by desiccator method,for particleboard and MDF,MC should be controlled within 9%-13%,while MC of DMDF should be within 7%-9%.On the other hand,the effects of MC on perforator values are obvious.When MC is within 3%-16%,perforator value increases linearly with MC increasing.It is effective to apply the MC correction factor to the perforator value when MC is within 3%-13%.
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