Patent attributes
A machine and method for making bags is described and includes a web traveling from an input section to a rotary drum, to an output section. The drum includes at least one seal bar, having a first sealing zone and an adjacent weakening zone. The weakening zone may be a heated perforator, heating wire, and/or may create an auxiliary sealed area. The heating wire is powered by a source of power at an adjustable voltage or magnitude, and/or pulsed, and/or with a feedback loop. The heating wire may make intermittent contact with the web and/or be disposed in an insert. The weakening zone may create a line of weakness that is uniform or varies in intensity, is a separating zone. The sealing zones may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.
