Slot-die coating technique has become a subject of interest owing to its mass and large area production characteristics. To date, numerous research on the fluid dynamics of coated solution and experimental decision of the coating conditions to improve quality of coated layer have been conducted. However, few studies have been done on the optimization of slot-die coater geometry owing to the high cost associated with its fabrication. In this study, we optimize the geometry of the slotdie coater using computational fluid dynamics. We used a statistical optimization technique (Box-Behnken design). In the optimization process, we determined the significant factors that affect the velocity variation of coated fluid in the transverse direction. An optimal geometry was derived using a desirability test which is generally used to evaluate the suitability of a selected geometry value based on the maximization of the velocity uniformity. Experimental results presenting the uniformity of the coated layer in the transverse direction improved from 4.7% to 1.4%.

In modern society, industries are being upgraded in various fields. In particular, the defense industry has developed numerous technologies, such as the localization of core military technologies. The defense industry is actively studying technologies in areas such as in helicopters and tanks. In the case of radars, research on the radar itself is very active as is the research on the components that make up the radar. In this study, the temperature distribution of the two types of evacuation centers that make up the radar were analyzed using Computer Fluid Dynamics (CFD) to identify the temperature distribution based on the internal structure of the shelter. The two types of shelters have different heating values in different arrangements in the shelter provided they have the same size of heat source. Simulation results showed that the average temperature at the KA LNA shelter was different. In this study, we analyzed the effects of internal structure on the temperature and confirmed that the internal temperature may be decreased by changing the structure without using an external cooling element.

Recent manufacturing methods for fabricating flexible devices have attracted a keen interest, with a strong demand by industrial manufactures. For thin film application on flexible devices, slot-die coating was found to be the most suitable method having excellent uniformity. Optimization of the reservoir of slot-die coater should be prioritized, since it is an important parameter affecting the uniformity of the final outcome of the coated layer. However, the numerous designs of reservoir makes prototyping difficult, and also results in high manufacturing cost. This study analyzed the velocity deviation of the slot-die coater outlet using CFD analysis, and shape optimization was performed by contour map. We introduce a facile and low-cost fabrication method for a slot-die coater, using polydimethylsiloxane materials and three-dimensional printing technique. The fabricated polymer slot-die coater was further evaluated by the leakage test of solution.

Computational fluid dynamic simulation based on the ABAQUS software was conducted to observe the inside flow of slot-die nozzle. The slot-die nozzle was modeled as 3-dimensional structure and three significant parameters were determined: inlet velocity of fluid, reservoir angles, number of strips none of which have been mentioned previously in the literature. The design of experiment, full factorial analysis was performed within determined design and process levels. The simulation result shows the inlet fluid velocity is most significant factor for the flows of inside nozzle. As an interaction effect, reservoir angle is closely related with number of strip that should address when the nozzle is designed. Moreover, the optimized values of each determined parameter were obtained as 35 mm/s of inlet velocity, 3 of strip numbers, and 22° of reservoir angles. Based on these parameters, the outlet velocity was obtained as 0.53% of outlet uniformity which is improved from 8.67% of nominal results.

Winding is one of the major processes in roll-to-roll systems. Taper tension profile in a winding determines the distribution of stress in the radial direction, i.e., the radial stress in the wound rolls. Maximum radial stress is major cause of material defect, and this study has been actively proceeded. Traditional models of radial stress model were focused on flexible and light substrate. In this study, we developed an advanced radial stress model including effects of both these parameters(weight and stiffness) on the radial stress. The accuracy of the developed model was verified through FEM(Finite Element Method) analysis. FEM result of maximum radial stress value corresponds to 99 % in comparison to result with the model. From this study, the material defects does not occur when the steel winding. And steel industry can be applied to improve the winding process.