Syringe Position Control for Back Pressure Modulated Drop Volume in Functional Inkjet Printing

Inkjet printing technologies have been common and well developed over the past few decades, and more recently have gained significant acceptance in functional printing and additive manufacturing applications. Control of dot gain in the deposition process is a desirable capability for a printing system from the perspective of process control and throughput, and preliminary data suggests dot gain and drop volume can be controlled in inkjet systems through manipulation of the reservoir back pressure. In order to help facilitate further exploration, the design of a back pressure control system is proposed, and the system modeled, with linear and nonlinear control designs proposed and compared in simulation for this nonlinear plant application, where the nonlinear control design, a sliding mode controller, outperforms the tested linear control design.