Techniques of Optimizing the UV Ink Jet Curing Process

Abstract

UV Ink Jet is rapidly gaining applications and uses in industrial markets requiring print-on-demand, variable information, and short-run graphics on an increasing variety of substrates. The performance properties of UV-cured materials are substantially affected by the lamp systems that are used to cure them. The development of the intended physical properties of a UV-cured ink can depend on how well these lamp factors are designed and managed, and how well the UV exposure is designed for the specific printer and print head arrangement. A number of variables of a lamp system, which can be designed or selected to produce the most efficient result, are discussed. Ink design, in terms of spectral absorbance and “optical thickness,” is fundamental to this relationship. The four key factors of UV exposure are: UV irradiance (or intensity), spectral distribution (wavelengths) of UV, total UV energy, and infra-red radiation. UV inks will exhibit very different response to peak irradiance or energy, and to different UV spectra. The ability to identify the various lamp characteristics and match them to the optical properties of the curable material, widens the range in which UV curing is a more efficient production process.