JY 520 is suitable for building-in on the cover of edition binding books. The temperature of the whole machine is controlled by eight-figure microcomputer chips, and is displayed by digital adjusting device with three-figure. The gas feed structure facilitates the operation, which make the machine work more steadily and the pressure better proportioned. The temperature, pressure, and position of the groove can be set and adjusted. The position of groove can be signaled by light.