... NL-5557,CE High Frequency PVC welding machine For Tarpaulins, Tents, Billboards, Signs, Truck Covers.The Series of High ... Frequency welding machine for Tarpaulins,Tents,Billboards, Signs,Truck Covers,Canvas,Membrane. Main Application ... machine is designed specifically for production of large format tarpaulins, tents, shading systems, truck covers, swimming pool covers, airline ...