Press Ink/Water Equilibrium and the Correlation to Laboratory Methods for Its Prediction

One of the most troublesome ink performance characteristics, water balance, is also one of the most difficult properties to determine off press. Several methods have been proposed to accurately predict this property, but their accuracy has been questioned. Most of the tests were developed from historical data, i.e. physical properties of inks that performed poorly were compared to the same properties for inks that performed well. Results of studies characterizing inks for printing properties and water balance utilizing a highly instrumented printing press are presented. The results are then compared to results obtained using a generally accepted laboratory method. Inks were also evaluated using a laboratory method developed in Europe and the results are compared to the findings from the press. Results of studies characterizing inks for printing properties and water balance utilizing a highly instrumented printing press are presented. The results are then compared to results obtained using a generally accepted laboratory method. Inks were also evaluated using a laboratory method developed in Europe and the results are compared to the findings from the press. A theory is presented which explains the differences observed between laboratory press results.