请教各位材料的专家，标准UL 1581上规定UL 60度的

护套料老化后抗张强度的保留率为：大于等于85% 

断裂伸长率的保留率为：大于等于45%

没有具体说明护套材料老化前和老化后的变化率为多少？请问各位大侠UL护套材料有没有这个变化率的要求。

护套材料老化前和老化后的变化率就为你上表所写的数据呀!

按照UL444第四版的标准，条款7.8.2所述，UL CM等级60C的护套应该在 100 ±2°C老化7天后，只要拉伸达到未老化前的50%，扩张达到未老化前的75%，就是合格的，而不是依据UL1581来判定。

7.8.2 For cables to be rated 60°C, jacket material removed from a length of finished cable shall meet the
aging test as follows. After 7 d, at 100 ±2°C, there shall be at least 50% retention of the unaged elongation
and 75% retention of unaged tensile strength when six specimens are tested in accordance with the test
procedures in CSA C22.2 No. 2556 or UL 2556, with the following modifications: