apparatus and method for closing and sealing lined taper top cartons wherein the cartons are advanced in a path of travel with their liner mouths open , the end walls of said carton and the opposite ends of the liner being simultaneously deflected inwardly and the front and rear carton walls and the opposite sides of the liner mouth concurrently displaced toward each other to juxtapose the upper edges of the front and rear walls with the liner mouth flattened therebetween , the flattened liner mouth then folded upon itself to form a double thickness mouth , the folded liner mouth and an end closure flap hinged to the carton rear wall then being simultaneously folded over the upper edge of the carton front wall and the folded closure flap secured to the front wall of the carton .