Patent ID: 6837029

Claim:
A method for the closure of an open end of a carton blank including a heat-sealable component, wherein the end side walls adjacent the open end of the carton are heated to at least their heat-sealing temperature and initially infolded to partially close the open end of the carton, comprising the steps of capturing the heated and initially infolded end side walls of the carton between a rigidly mounted backup pad disposed within the interior of the carton blank and a pressure pad disposed externally of the carton blank and mounted for reciprocative movement toward and away from said backup mandrel, disposing a linearly reciprocative cam in operative relationship to said pressure pad to apply pressure to said pad upon linear movement of said cam toward said pressure pad, providing on said cam a camming face disposed opposite said pressure pad, providing a cam follower disposed adjacent to and in operative relationship to said camming surface, applying a force against said cam follower in a direction substantially perpendicular to the direction of linear movement of said cam to thereby move said cam and said pressure pad toward said backup pad by a distance sufficient to press the infolded end side wall portions of the carton blank into intimate overlying relationship to one another, and maintaining said pressure applied to said infolded end side wall portions for a time sufficient to effect solidification and sealing of said infolded end side wall portions to one another and thereby close the end of the carton blank.