A study on PCB layout design for non-isolated three-phase Inverter with PFC

Abstract

Slot coating is a common method of manufacturing films such as optical films, adhesive tapes, etc. It is a pre-metered method: the final wet film thickness is set by the flow rate and the web speed, and independent of other operating parameters and coating liquid properties. Therefore, it is ideal for precise film thickness control. To produce uniform film, the coating flow needs to be steady-state, two-dimensional, and stable. In the slot coating process, however, there are always some small-scale disturbances generated by rotating process units, such as pumps, rolls, etc., and they usually have periodicity. These disturbances cause a non-uniformity of the moving web direction and could spoil the film quality. Therefore, the sensitivity analysis of coating flow under the periodic disturbances is important. Among all disturbances, a change of coating gap, i.e. the distance between the die lip and the moving substrate, is known to the most dangerous disturbance. This type of disturbance is usually called the gap oscillation, and caused by the substrate thickness variations, mechanical vibration of the coating die or roll, and roll run outs. Here, we analyze the effect of fluid properties, operating conditions and die configurations on response of slot coating flow to gap disturbances. In this study, we use Galerkin/finite element method to solve transient Navier-Stokes equation under periodic disturbance. We define the amplification factor as an indicator of film non-uniformity and analyze the effect of different parameters by comparing the factor. In particular, we use Carreau-Yasuda model to describe shear-thinning property of xanthan gum solution and compare with Newtonian fluid. © 2016 AIP Publishing LLC.