Abstract: This disclosure relates to a carton forming apparatus particularly adapted to receive a carton blank intended to be folded into a carton having a sleeve along one edge thereof, the carton forming apparatus being of a construction providing for automatic operation thereof throughout. The apparatus includes automatic feed mechanisms, cooperating blade and plow devices for effecting a folding of an edge flap, combination folder and retainer apparatus for folding a next adjacent carton panel while retaining the folded flap in its folded state, and an adhesive applying device for applying adhesive to the carton blank in alignment with the folded position of the edge flap for bonding the edge flap to the main portion of the carton. The plow and blade devices are mounted for adjustment to accommodate carton blanks with different edge flap widths. The folder and retainer devices are formed in sections and readily removable from the apparatus.