Method and apparatus for making skirtless seals
AssigneeCMD Corporation
InventorsPaul A. Selle, Gregory T. Prellwitz
Life of this patent
Estimating the term…
Abstract
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 rotary drum includes at least one seal bar, having a single sealing zone, and a weakening zone disposed within the single sealing zone. The single sealing zone may be a heated perforator, and may include a heating wire. The heating wire may be an NiCr wire stitched into the heater, and be disposed on a cap or on the seal bar. The weakening zone may create a line of weakness that is uniform or varies in intensity. The sealing zone may include temperature zones, cartridge heaters, cooling air, or heated air, or a source of ultrasonic, microwave or radiative energy.
Claims38
A bag machine, comprising:
- an input section;
- a rotary drum, disposed to receive a web from the input section, wherein the rotary drum includes at least one seal bar;
- an output section, disposed to receive the web from the rotary drum;
- wherein the at least one seal bar includes a sealing zone that forms a single seal, and further includes a heating wire that is a weakening zone within the sealing zone, that forms a weakened zone within the single seal;
- and
- a release layer on at least a part of the sealing zone.
A method of making bags comprising:
- receiving a web;
- forming a single seal on the web using a seal bar on a rotary drum by bringing the web into contact with a seal bar having a releasing layer over at least part of a sealing surface;
- forming a perforation within the single seal for at least a portion of the time the single seal is being formed by bringing the web into contact with a heating wire;
- and
- releasing the web from the seal bar.
A bag machine, comprising:
- means for receiving a web;
- sealing means for melting the web and imparting a single seal and a weakened zone within the single seal onto the web as the web passes around a rotary drum;
- release means for helping the melted web release from the sealing means.
A perforator for a rotary bag machine comprising a release layer for mounting over a heater, and a heating wire stitched into the release layer and the heater.
Dependencies are inferred from the claim text.