ASTM D4364-2013测试标准

ASTM D4364 以聚集自然光源（固定赤道聚镜自然加速老化仪）对塑料材料进行室外加速老化测试的标准方法（利用集中自然光进行塑料户外加速老化试验的标准操作规程）

ASTM D4364-2013发行信息

标准号 ASTM D4364-2013

中文名 利用集中自然光进行塑料户外加速老化试验的标准操作规程

英文名 Standard Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated Sunlight

发布日期2013

实施日期

废止日期无

中国标准分类号G31

国际标准分类号83.080.01 (Plastics in general)

发布单位US-ASTM

ASTM D4364-2013适用范围

4.1本规程涉及通过平面镜系统对阳光进行浓缩，平面镜系统的布置旨在模拟抛物线槽，抛物线槽聚焦在安装试样的风冷靶板上。表1中描述了本方法中常用的有喷水和无喷水的暴露周期。经相关方协商一致，可使用表1中未列出的其他暴露周期。

4.1 This practice involves the concentration of sunlight by a system of plane mirrors, arranged to simulate a parabolic trough focused on an air-cooled target board on which the test specimens are mounted. Exposure cycles with and without water spray that are commonly used for this method are described in Table 1. Other exposure cycles not listed in Table 1 can be used, upon consensual agreement between interested parties.

4.1.1 Accelerated outdoor exposure tests performed using this practice in an absence of a programmed moisture cycle are intended to simulate conventional exposure testing on racks facing the equator in desert and arid regions.

4.1.2 Accelerated outdoor exposure tests performed using this practice with a programmed moisture cycle shall possess the feature of spraying high purity water on the specimens in a regular, periodic fashion that is intended to simulate the results of conventional exposure testing on fixed racks facing the equator in subtropical, semi-humid, and temperate regions. Water-spray cycles that are recommended by this practice are given in Table 1.

4.2 The effectiveness of the Fresnel-reflector accelerated outdoor weathering test machines depends primarily on the amount and character of the UV in the direct-beam component of sunlight.

Note 2x2014;Use of the apparatus in regions of moderate- to high-diffuse irradiance will reduce the test machinex0027;s effectiveness substantially for providing concentrated UV in the target (specimen) area.

4.3 Testing to specific levels (quantities) of solar ultraviolet radiant exposure is recommended. Elapsed time exposure-level determinations shall not be used for testing with this practice. Testing to specific levels of UV irradiation, whether to total UV or within selected wavebands, is an effective method for improving agreement between wintertime and summertime testing on the Fresnel-reflector weathering-test machines. Other seasonal factors such as temperature and time of wetness can affect the weathering of test specimens significantly.

4.4 The weathering machines described provide for specimen cooling that reduces thermal problems in most materials. It is recommended that monthly temperature measurements be performed on heat-sensitive plastics to record the typical monthly test specimen temperatures.

Note 3x2014;It is possible for heat-sensitive plastic materials and thick specimens that are self-insulating to exhibit thermal-induced degradation that is unrealistic compared to natural weathering. Clear, thin-film photodegradable plastics are not recommended for testing with this practice for this reason.

4.5 Since the natural environment varies with respect to time, geography, and topography, it can be expected that the effects of natural exposure will vary accordingly. Furthermore, all materials are not affected equally by increased irradiance and temperature. ......