RESEARCH AND DEVELOPMENT OF AN AUTOMATIC INK DOSING AND FEEDING SYSTEM FOR SCREEN PRINTING MACHINES

Abstract

The article addresses the development of a controlled dosing unit and the substantiation of cyclic feeding parameters according to the technological load of a screen-printing machine. The computational study covered 8 screen mesh configurations, 9 loading modes, and 10 bench-test modes. The methods included material balance analysis, a power-law rheological model, screw-drive calculations, and discrete feedback-based dose correction. For meshes ranging from 90 to 300 threads per inch, the cyclic ink transfer ranged from 2.25 to 2.98 mL. As print coverage increased from 20% to 100%, the commanded dose rose from 0.90 to 4.40 mL, while the delivery rate increased from 7.2 to 105.6 mL/min. This comparison demonstrates that a fixed valve-opening time is unsuitable under variable loading conditions. For a piston diameter of 32 mm, the actual delivery per revolution is 3.72 mL/rev, while the calculated torque, including the safety margin, reaches 0.675 N·m. The applicability of the results is limited by the need for bench verification of the target metrological parameters. The proposed solution combines calculation of material demand with correction of the subsequent dose according to the current ink reserve. Designers of printing equipment can use the obtained parameters to design dosing modules and configure servo drives.