Abstract

In offset lithography, ink has been shown to pickup significant quantities of fountain solution as emulsified droplets. Good printability of lithographic inks is dependent on the balance between the flow of ink and water (fountain solution). Water pickup of ink is directly related to emulsification capacity. Emulsification must be controlled by using the correct fountain solution and proper surface tension value of fountain solution. If inks do not properly emulsify, ink tack may vary on the press during printing. Ink tack is expected to strongly influence printability and runnability of offset lithographic inks. Tack measurement is used as a production control testing and for the assessment of paper surface strength. The purpose of this thesis was to determine the relationship between emulsification and tack of offset lithographic inks. This research studied the water pickup characteristics of ink using different fountain solution surface tension values and different fountain solution. To observe any differences due to ink vehicle, three different oil-based inks: conventional, soybean, and vegetable were used and studied.. For increased understanding of the relationship between emulsification and tack, an inkometer was used to study the ink tack response of different emulsified inks and the inks before emulsify fountain solution into their bodies. The effect of added water on the rheological properties (tack response) of unemulsified lithographic ink was also studied. This study indicates a change in water pickup characteristics due to surface tension value of fountain solution and the various fountain solutions tested. There is a significant effect due to the various oil-based inks on water pickup of the ink. Tack response is considerably affected by the capacity of the ink to pickup water. Adding water into the ink greatly affects the tack value response. The tack of the ink will fall in value as water is emulsified into the ink.

Library of Congress Subject Headings

Printing ink--Testing; Lithography--Printing

Publication Date

11-1-1994

Document Type

Thesis

Department, Program, or Center

School of Print Media (CIAS)

Advisor

Daniels, Chester

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: Z247 .B66 1994

Campus

RIT – Main Campus

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