The working principle of the ink wheel coding machine is to melt the ink in the solid ink wheel and print it on the object to be printed in contact with the characters on the rotary printing machine. The ink wheel coding machine is light and precise in manufacture. Special zinc alloy characters (which can be customized according to customer's requirements, font types: 1. The font direction is the same as or opposite to the feeding direction, which is called T-shaped characters; 2. The font direction is perpendicular to the feeding direction, which is called R-shaped characters), with long service life and easy replacement. The printing position is electronically controlled and can be adjusted at will. Printing action and counting are controlled by photoelectric switch, and the number of printed sheets can be set.