ASTM D4364 以聚集自然光源（固定赤道聚鏡自然加速老化儀）對塑料材料進行室外加速老化測試的標準方法（利用集中自然光進行塑料戶外加速老化試驗的標準操作規(guī)程）

ASTM D4364-2013發(fā)行信息

標準號 ASTM D4364-2013

中文名 利用集中自然光進行塑料戶外加速老化試驗的標準操作規(guī)程

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

發(fā)布日期2013

實施日期

廢止日期無

中國標準分類號G31

國際標準分類號83.080.01 (Plastics in general)

發(fā)布單位US-ASTM

ASTM D4364-2013適用范圍

4.1本規(guī)程涉及通過平面鏡系統(tǒng)對陽光進行濃縮，平面鏡系統(tǒng)的布置旨在模擬拋物線槽，拋物線槽聚焦在安裝試樣的風(fēng)冷靶板上。表1中描述了本方法中常用的有噴水和無噴水的暴露周期。經(jīng)相關(guān)方協(xié)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. ......