... used in aeronautical engineering,trains,cars,and ships,new honeycombed materials for light-weighted wall,partitions(wall and board),furniture,doors ... inflammable and/or explosive cargo. Main Technical Indexes1.Flame retardancy:B1-grade flame retardant materials(GB/T8624) Oxygen index: >35(GB/T2406) Smoke ... honeycombed boards with various area densities,honeycomb-sizes,and paper materials.