Apparatus for sealing and creating a thermal perforation
AssigneePactiv Corporation
InventorsMichael L. Bohn, William P. Belias
Life of this patent
Estimating the term…
Abstract
A method for simultaneously sealing and creating a thermal perforation between two thermoplastic layers that comprises providing two thermoplastic layers. A drum is provided that has at least one sealbar and perforation assembly. The two thermoplastic layers are contacted to the sealbar and perforation assembly. The thermoplastic layers are sealed with two generally opposing parallel seals and simultaneously create a thermal perforation in the thermoplastic layers generally parallel to the opposing seals. The thermal perforation is located between the two opposing seals.
Claims23
A rotary drum for simultaneously sealing and creating a thermal perforation between two thermoplastic layers, the drum comprising at least one sealbar and perforation assembly, the assembly having a body, a perforation insert and at least one heating source, the body having a cavity therein and opposing first and second sealing surfaces, the perforation insert being located in the cavity and having a perforating surface, the at least one heating source adapted to supply heat to the first and second sealing surfaces and the perforating surface, wherein the material of the perforating surface has a coefficient of thermal conductivity that is greater than a coefficient of thermal conductivity of the material forming the first sealing surface and the material forming the second sealing surface.
A rotary drum for simultaneously sealing and creating a thermal perforation between two thermoplastic layers, the drum comprising at least one sealbar and perforation assembly, the assembly having a body, a perforation insert and at least one heating source, the body having a cavity therein and opposing first and second sealing surfaces, the perforation insert being located in the cavity and having a perforating surface, the at least one heating source adapted to supply heat to the first and second sealing surfaces and the perforating surface, the perforating surface comprising aluminum, nickel, copper or combinations thereof, the first and second sealing surfaces comprising stainless steel or stainless steel alloys and wherein the material of the perforating surface has a coefficient of thermal conductivity that is greater than a coefficient of thermal conductivity of the material forming the first sealing surface and the material forming the second sealing surface.
Dependencies are inferred from the claim text.