护套：挤包在内护层上的护套应采用PVC.ST4型聚氯乙烯混合物。

Sheath: PVC. ST4 model PVC mixture should be adopted as the inner sheath.

youdao

护套：挤包在内护层上的护套应采用PVC.ST4型聚氯乙烯混合物。

Sheath: PVC. ST4 model PVC mixture should be adopted as the inner sheath.

youdao