The present disclosure relates to a cartridge for containing toner material used in an image-forming device. The cartridge comprises a developer roll, two J-seals that provide interfaces with the developer roll at the ends thereof, and an air duct that conducts airflow across the interfaces to cool the developer roll and seals. The air duct comprises an elongated hollow body and a pair of nozzles in fluid communication with the hollow body. One of the nozzles is disposed at a distal end of the developer roll near one J-seal, and the other of the nozzles is disposed at a proximal end of the developer roll near the second J-seal.
