Acoustic Ink Printing with Solid Ink

Abstract

We have adapted the Acoustic Ink Printing (AIP) printhead for operation at 150C, and have demonstrated printing with solid ink for high image quality on plain paper. In AIP, an ultrasonic beam is focused on the free surface of the ink to eject discreet droplets of controlled diameter. The drop size is determined by the lateral dimension of the acoustic beam. Hence, AIP is a “nozzleless” drop ejection process that enables generation of extremely small drops. We have used 2.7 pl drops of a molten wax (i.e. solid ink) to produce images at a quality level exceeding xerography on plain paper. The printing is done at a spatial addressability of 600 spots per inch and the printed spot size can be varied by firing from 0 to 5 drops per pixel to achieve multiple gray levels at high resolution. For solid ink printing, we have modified the 1024-ejector aqueous AIP printhead materials and assembly process to enable 150C operation with a flowing layer of 13 cp molten wax.