... Protection4. Replace Metal Mesh,Plastic gridPerformance of HockGrid® Mine Grid (Polyester Geogrid) 1000-1000kN/mAmong traditional methods, room-and-pillar or ... : 30/30,40/40,50/50,60/60,80/80,100/80,120/120,200/200,300/300,400/400,600 ... . Shandong Hock Mining Engineering Co.,Ltd Mine Grid,Mining Grid,Polyester Geogrid Manufacturers. Polyester Mine Grid 1000-1000kN/m for Longwall Recovery Systems