Patent ID: 6165115
Filing Date: 2000-12-26
Classification: B29C,B31B

Abstract:
Process for closing and hermetically sealing a bottom end of a composite paper container comprising:providing a cylindrical shaped container body constructed of a composite including paper body plies and having an inside heat-sealable polymer surface and an open bottom end;forming a flange of a predetermined diameter on and around the bottom end of the cylindrical container body which extends outwardly from the container body at a sharp radius of approximately 90.degree. to an outside surface of the container body and which defines a flat circular heat-sealable surface on an outer side of the flange;positioning a flat generally circular membrane patch, constructed of a composite including paper plies and being of a predetermined diameter generally equal to the diameter of said flange and having an inside heat-sealable polymer surface, on the flat circular heat-sealable surface of the container body flange for covering the open bottom end of the container body;heat-sealing the heat-sealable surfaces of the container body flange and the membrane patch to each other for hermetically sealing the container bottom end;positioning a generally circular reinforcing plug having a predetermined diameter less than the predetermined diameter of said membrane patch on the membrane patch; andcurling the container body flange and the portion of the membrane patch heat-sealed thereto inwardly of the cylindrical container body and over and around an outside periphery of the reinforcing plug while applying heat and pressure to complete closure of the container bottom and to maintain the cylindrical shape of the container.