a gas barrier folding carton formed from a unitary paperboard blank having a gas impermeable polymer layer such as evoh , nylon , or foil extruded on or laminated to one surface of the blank , except for certain adhesive coated areas . two opposite side edges of the blank are seamed to form a flattened tube having top and bottom closure flaps . one of the major closure flaps at each top and bottom container end is provided with spaced abhesive areas , with areas of the two minor closure flaps also provided with abhesive . upon folding the closure flaps at each end , the folding sequence pulls the barrier film away from the abhesive areas and subsequent heat sealing produces hermetic sealing of the carton . this process and carton construction may be employed with conventional gas purging of the container interior by an inert gas before final sealing .