Modeling Studies of Ink, Plate and Fountain Interactions by Contact Angle Measurements

Spreading index has been considered as an important property of an ink-plate-fountain system. A new method is proposed to measure spreading index from the contact angles of fountain surrounded ink droplets and ink surrounded fountain droplets on plate image area. Application to model systems has illustrated the capability of the proposed method to probe three-phase interactions, for which a previous method is inherently deficient. With the proposed method, the adverse effect of image area is demonstrated. Also demonstrated is the difference between Soy oil and mineral oil. three-phase interactions, for which a previous method is inherently deficient. With the proposed method, the adverse effect of image area is demonstrated. Also demonstrated is the difference between Soy oil and mineral oil.