ASTM D635是对于水平位置塑料的燃烧速率或者蔓延程度及燃烧时间的测试。

　　ASTM D635: Standard test method for rate of burning and/or extent and time of burning of plastics in a horizontal position.

    ASTM D635:水平位置塑料的燃烧速率或蔓延程度及燃烧时间的测试.

　　ASTM D635测试方法此方法为测定硬质(自承塑料)的燃烧速率的测试，此方法类似于UL 94HB法。只是样品的尺寸略有不同。从样品任意端点作标记，在距离100m处作为另一个标记。样品的长边水平放置，短边与水平边成45°角。以蓝焰长20mm的本生灯火焰施加于样品30s，如样品燃烧达100mm标记处，测定平均燃烧速率(mm／min)；如试样燃烧未达100mm标记处即自熄，测定平均燃烧时间(s)和平均燃烧长度(mm)，根据有关建筑规范将塑料分级。

　　ASTM D635等级分为A、B、C、D四个等级

    ASTM D635 Class A: there is no visible sign of combustion after the source is removed.

    ASTM D635 Class B: The flame front does no pass the 25mm reference after the source is removed

    ASTM D635 Class C: The flame front does pass the 25mm but does not reach the 100mm reference mark.

    ASTM D635 Class D: The flame front reaches the100mm reference mark and the linear burning rate does not exceed 40mm/min for specimens.

　　ASTM D635样品要求125mm*13mm*厚度