What does the PE side of SBS waterproof membrane mean?
Is the side of the composite PE film The correct representation method of SBS waterproof membrane: SBS Ⅰ PY PE PE 4 10 GB18242-2008; when simplified, it is written as: SBS Ⅰ PY PE PE 4. The meaning of the expression (SBS waterproof membrane) (type I) (polyester felt carcass) (the upper surface is PE polyethylene film surface)) (the lower surface is PE polyethylene film surface) (thickness is 4mm)