A Papermaker's Approach to the Analysis of Paper Printing Characteristics

With constantly changing papermaking and printing processes, the update of old methods to assess the printing characteristics of paper and the development of new diagnostic methods to define the print-related properties for new paper grades are required by both papermakers and printer. A new comprehensive approach to the problem has been taken at the Pulp and Paper Research Institute of Canada. A two-color research web offset press built at the Institute is used in controlled reproducible print runs to evaluate the fundamental principles of paper linting. The press is also used in a factorial experiment to differentiate paper properties responsible for linting from pure press parameters. Some preliminary results indicate the relative importance of dampening, blanket properties as compared to paper furnish composition. A two-color research web offset press built at the Institute is used in controlled reproducible print runs to evaluate the fundamental principles of paper linting. The press is also used in a factorial experiment to differentiate paper properties responsible for linting from pure press parameters. Some preliminary results indicate the relative importance of dampening, blanket properties as compared to paper furnish composition. The fundamentals of ink transfer to paper and ink film splitting in the printing nip are studies applying new concepts. The new test called Printing Efficiency contains three indices defined as the ratio of print density, print-through, and set-off at the ink transfer curve maximum to the ink weight transferred to the paper at this maximum. The indices are then compared as a function of the paper air-leak roughness value. The Printing Efficiency test has been shown to be more sensitive to paper variables than conventional tests used in the paper industry.