Ultrasonic atomisation: a novel technique for surface coatings

Abstract

In this work, ultrasonic atomisation as a possible spray coating on a moving surface has been studied. The experimental method employed here involved the spraying of ink vertically downwards onto a paper, which was moving laterally. It was found that the percentage area of the covered surface increased with an increase in the height of the ultrasound atomiser from the surface and the vibrational amplitude of the atomiser, while the liquid film thickness on the coated surface decreased with an increase in the height of the ultrasound atomiser, vibrational amplitude of the atomiser and the linear velocity of the moving surface. Also, it was observed that the percentage area as well as the liquid film thickness increased with an increase in the liquid flow rate irrespective of changes in other parameters. The increase in the viscosity of the spraying liquid reduced the area covered by the spray for surface coating, while it increased the coating film thickness.