... .For door and window welding 2.PC control 3.Welding four, three,two or one corner 4.Wide processing range 5.CE ISO9001:2000 Four head welding machine for pvc window making machine ... 1.Window machine is used for PVC door-window welding.2.Welding four, three,two or one corner, transom,cross transom and special angles.3 ...