Simulation Study And Analysis Of Thermal Bubble Inkjet Process

Thermal bubble inkjet printing equipment has the advantages of simple structure and low cost,and is widely used in daily life and office areas,but also printing electronics and other processing fields commonly used technology,with good prospects for research and application.However,there are two shortcomings in the practical application of thermal bubble inkjet:on the one hand,the inkjet head and the heating element are integrated design,and in the event of damage to the heating element,the inkjet head needs to be replaced as a whole,which will increase unnecessary costs;on the other hand,the thermal bubble inkjet technology can select a small range of ink viscosity,which makes the printing accuracy of thermal bubble inkjet technology is somewhat limited.To address this problem,the key processes of ink droplet formation,ink jet and ink droplet curing deposition on the substrate surface in the thermal bubble inkjet process are studied by using simulation,in order to study the thermal bubble inkjet process in depth,and on this basis,focus on the structure of the thermal bubble inkjet head to propose a modified design.The main research contents are as follows:(1)Mathematical modeling of the process from ink droplet formation to fracture in thermal bubble inkjet,using a one-dimensional heat transfer equation to represent the energy exchange between the bubbles generated in the ink and the surrounding ink after the heating element begins to heat up and the temperature change at the interface between the bubbles and the ink.A correlation equation based on the interrelationship between temperature and pressure is established and used to represent the entire process from the growth of ink bubbles to their rupture during the heating process,and to analyze the change law between pressure and temperature in the ink cavity.(2)To study and analyze the process of ink droplet formation and jetting by using the simulation method.The effect of different types of inkjet heads and ink parameters(viscosity,density,surface tension)on the inkjet speed and droplet state is investigated.By analyzing the droplet speed and droplet form obtained from the simulation,the ink viscosity is an important factor affecting the stable ink jet.The existing inkjet head structure proposed a modification design,and then the simulation analysis of different structures of the inkjet head,to obtain the same heating temperature in the concave cone inkjet head inkjet speed compared to the ordinary conical inkj et head can be increased by a maximum of 20.11%.(3)An air domain of 30×30×30 ?m3 and ink droplets with a diameter of 10 ?m were established to investigate the curing deposition pattern of ink droplets on the surface of substrate,and the effects of factors such as ink droplet viscosity,ink droplet surface tension,ink droplet initial velocity,contact angle and different substrates on the curing deposition of ink droplets on substrate were analyzed.