Abstract
Cleaning technique to remove fine particles on a surface under dry environment is greatly wanted in manufacturing processes of liquid crystal display (LCD), functional films and so on. However, it becomes usually difficult to remove the fine particles by the impingement of simple air jet because the particles stick to the surface in the viscous sublayer by adhesive forces such as Van der Waals force. In this study, a cleaning device equipped with a special nozzle having triangular cavities was developed to remove the fine particles. The experimental results in the preceding report suggested that the removal rate of fine particles can be enhanced by the pressure or velocity fluctuation generated by the special nozzle. The aim of this study is to clarify the removal mechanism of fine particles from experimental and numerical investigations. First the adhesive forces of particles to the wall are experimentally measured by the centrifugal force method. Then the results are compared with several kinds of hydrodynamic removal forces such as drag and lift estimated from the numerical simulations. In addition we consider a removal force resulted from pressure gradient fluctuation induced by the impingement of a strongly turbulent air flow. The physical mechanism for removing particles is discussed through the comparison with the numerical results.
