... longwall face recovery efficiency and security. polyester mesh is 3-6 m wide and 50-200 m long with tensile strength ranging ... self-ignition risks. Shandong Hock Mining Engineering Co.,Ltd Mine Grid,Mining Grid,Mining Geogrid,Polyester Geogrid,Biaxial Geogrid. mine grid 400-400kN/m for longwall recovery system,rib ...