Fixing valves to plastic bags - by welding to a hole punched in the bag

摘要

Plastic bags or sheets to be converted into bags are treated in a device having a punch and a welding head arranged concentrically but possessing independent drives, so that after the bag or sheet is perforated the valve may be welded around the perforation. For automatic sealing valves onto plastic sheets or bags. The valves are supplied one at a time in a position to be welded, along the axis of the orifice and the punch. A tube for aspiration serves to remove the punched out waste. If the device is used to attach valves to a plastic sheet the sheet is passed through traction rolls coupled through rack and pinion to an electromagnetic drive which moves the sheet forward in steps.