塑料.通过氧指数测定其燃烧性.第3部分:高温试验

[中文适用范围]： 本文件规定了确定氧气与氮气混合物中最小体积分数的方法，该方法将支持小型垂直测试样本在指定测试条件下在 25 °C 至 150 °C 的温度范围内燃烧。 温度范围通常在 40 °C 至 150 °C 之间。 结果定义为测试温度下的温度指数值，这是塑料材料在过热使用情况下可能经历的典型实际温度。 提供了测试在测试温度下以垂直棒或板形式自支撑材料的方法，厚度可达 10.5 毫米。 然而，它们不适用于需要 ISO 4589-2:2017 表 2 中定义的支撑框架的 V 型。 这些方法适用于表观密度为 100 kg/m3 或更高的固体、层压或多孔材料。 该方法还适用于一些表观密度小于100 kg/m3的多孔材料。 提供了一种用于在垂直支撑时测试柔性片材或薄膜材料的方法。 本文件还包括一种方法（参见附录 A），用于确定在指定测试条件下，空气中小型垂直测试样本的 OI 为 20.9% 时的温度。 发生这种情况的温度被定义为可燃温度 (FT)，该方法仅限于测定低于 400 °C 的温度。 该方法不适用于 OI 为 [外文原描述]： ISO 4589-3:2017 specifies methods for determining the minimum volume fraction of oxygen, in a mixture with nitrogen, that will support combustion of small vertical test specimens under specified test conditions over a range of temperatures between 25 °C and 150 °C. The range of temperatures is typically between 40 °C and 150 °C. The results are defined as temperature index values at the test temperature, which is typical of the practical temperature that a plastic material can experience in an overheated service situation. Methods are provided for testing materials that are self-supporting at the test temperature in the form of vertical bars or sheet up to 10,5 mm thick. However, they are not applicable to form V which requires a supporting frame as defined in ISO 4589‑2:2017, Table 2. These methods are suitable for solid, laminated or cellular materials characterized by an apparent density 100 kg/m3 or higher. The methods are also applicable to some cellular materials having an apparent density of less than 100 kg/m3. A method is provided for testing flexible sheet or film materials while supported vertically. ISO 4589-3:2017 also includes a method (see Annex A) for determining the temperature at which the OI of small vertical test specimens in air is 20,9 % under specified test conditions. The temperature at which this occurs is defined as the flammability temperature (FT) and the method is limited to the determination of temperatures less than 400 °C. The method is not applicable to materials having an OI of <20,9 %.