... .weather resisitance 3.does not seep 4.easy installation 5.flame retardant Polycarbonate corrugated sheet features: It has has the outward appearance ... the acid and alkali the corrosion, bears the aging, being flame-resistant, the cross section size standard, does not seep, the ... B1 level (based on the Natinal GB8625-88 test,without flame or toxic gal) 5.Buring resistance:without poor quality due ...