| Abstract [eng] |
The most well-known and commonly used printing techniques made the inkjet printing technology more popular among manufacturers for its simplicity and flexibility. Demand for printing products is increasing in such areas as textile printing, microchip production and personalised production, raising quality re-quirements. Thus, inkjet printing is continuously enhancing its capabilities. With the printing market expected to grow, there are many propositions to improve the productivity of inkjet process. The dissertation aims to study the dynamics of an inkjet droplet at different stages of its formation, considering its interaction with the surface to improve the quality and speed of high-class inkjet printing and im-prove inkjet printhead testing applications. The present dissertation reviews theo-retical and numerical techniques of inkjet printing process modelling by applying the Computational Fluid Dynamics (CFD) module using the finite elements method. Inkjet printing inks are calculated as Newtonian fluid. The ink flow is modelled by the incompressible Navier–Stokes equations. The presented simula-tion model is solved using a level set method to determine the ink and air interface. Experimental investigation results are reported on the inkjet printing process col-our reproduction on different linen fabrics, and modelling results are given for droplet ejecting, printing and interaction processes with the flat surface and the interaction with the inkjet droplet with physically treated polymer surfaces. Based on systematic and analysed numerical simulations of research on the operation of inkjet printing heads, Article 1 describes the inkjet printhead models, which analyse how different inks impact droplet formation and movement at dif-ferent time steps. Article 2 presents an experimental realisation of colour reproduction by inkjet printing possibilities on different materials in different printing settings. Article 3 presents the physical and numerical experiments on the impact char-acteristics of inkjet printhead droplets with flat surfaces. Different surface treat-ment methods were investigated to increase droplet adhesion with flat surfaces. Article 4 investigates the numerical model of the print head modelled in three-dimensional space. Various parameters of drop formation and fall were experi-mentally determined with a change in the time of the excitation impulse. A nu-merical analysis was carried out regarding the influence of the excitation time on the droplet formation and further movement. The supplemented articles were published in four peer-reviewed scientific journals listed in the Clarivate Analytics Web of Science database with an impact factor. The study results were presented at three international conferences. |
