冷屋面涂料实验室加速污染老化方法研究

Study on laboratory accelerated pollution and weathering method of cool roof coatings

自然界污染和材料老化会降低屋面材料的太阳光反射比,影响其反射隔热效果。为在实验室快速模拟冷屋面涂料在北京地区污染老化后反射比的变化情况,研究了加速污染老化方法。将粉尘、炭黑、腐殖酸和无机盐组成的混合污染液通过自动喷污装置喷洒在试样上,经老化试验箱的周期性紫外照射、加热和冷凝,与经2年自然老化后的相同试样比较,两者太阳光反射比差值在±0.02以内,冷屋面涂料自然老化后的反射特性在实验室内得以复现。该方法可用于冷屋面涂料的研发、设计选材和寿命评价。

Natural pollution and material aging reduce the solar reflectance of roof materials,thus affecting the reflective and thermal insulation effect.The accelerated pollution and weathering method is studied to simulate the change of reflectance of cool roof coatings after pollution and weathering in Beijing.The sample is sprayed with mixed pollution liquid composed of dust,soot,humic acid and inorganic salt by automatic spraying device,and then subjected to cycles of ultraviolet irradiation,heating and condensation in the aging test chamber.Compared with the sample after 2 years of natural weathering,the difference of solar reflectance is within±0.02.The reflection characteristics of cold roof coating after natural weathering are reproduced in the laboratory.This method can be used in the research and development,design,material selection and life evaluation of cool roof coatings.