Details:
Summary:
Gravure publication paper grades with different physical and chemical properties (porosity, contact angle) accept at the same printing conditions (ink viscosity, press speed impression pressure, ESA-electrostatic-assisted ink transfer, etc.) different amounts of ink. Ink mileage for SCA grades is higher than that of LWC grades, while the printout reflection density of SCA is lower. The transfer of ink is further affected by press speed and ink viscosity. Ink transfer decreases with increasing press speed. It is difficult to predict the ink mileage by measuring optical properties alone, (reflection optical density, CIE L*a*b* values) - because of non-uniform absorption of the ink and ink hold-out. Parker Print Surf porosity of the substrate was found to be an excellent predictor of ink mileage. Absorptivity of the paper substrate was found to be linearly correlated with ink mileage and was determined to be the best parameter for predicting ink mileage.