... stair treads, and trench covers for loading frames.Molded FRP gratings use high strength fiberglass roving as reinforcing material, ... grit, flat or decorative plating, etc.Mold resin system for FRP grating products:1) Type O (orthophthalic polyester resin): a ... used in middle concentration inorganic acids, inorganic alkalis, and other special environments b) Operation temperature: 50 ~ 90°C;3) Type ...