... .polyester mine grid 400-400kN/m for long-wall recovery system roof support,hock mining geogrid,Shandong Hock MiningMine Grid Introduction ... types and specifiactions according to the requirements of projects.The data hereinbefore was derived from the experiments in the lab. They ... ,Biaxial Geogrid. mine grid 400-400kN/m for longwall recovery system,rib and roof support