Drying Technology Using Laser Exposure for High-speed Inkjet Printing

Abstract

To ensure reliability with high-speed inkjet printing devices that print at 200 m/min using water-based ink, it is important for ink to penetrate and dry at high speeds. With current drying devices that use heating drums, heat is applied to the entire surface of the paper from the back side of the printed surface. Since it is not possible to avoid the rise in temperature to portions of the paper where ink is not applied, differences in the amount of paper deformation occur between printed areas where expansion/cockling occurs due to water and non-printed areas of the paper that shrink. As a result, this causes creases to the paper. To avoid this problem, the authors examined the use of infrared laser exposure for drying. With laser exposure, ink is directly heated and strong drying energy can be applied instantaneously, enabling for only the ink to be dried and for drying to occur in nearly the same time span as ink penetration. As a result, an increase in the temperature of the non-printed areas is prevented, and deformation of the paper is controlled no matter the amount of ink applied; by controlling ink penetration, feathering/linebleeding is reduced and image quality is improved.