Details:
Summary:
There are many different materials and consumables that are used within a web offset environment, including the fountain solutions. As with all consumables there are trends that are seen in their evolution over time. Currently there is a move towards higher pH levels in the North American market and also to the inclusion of additives that will aid with the corrosion resistance of the fountain solution. This paper addresses these issues by carrying an experimental program. The study evaluated the impact of the fountain solution changes on, paper, ink, printing plates and dampening rollers on several different print characteristics. These were the latitude of the water window on the press, the waste levels generated through the start up procedure, the steady state runnability of the press, the amount of piling formed on the printing blanket and ink feedback into the dampening system. The trial procedure was developed to best utilize the time on press, using DOE procedures in 42 trials. The run length for the water window was approximately 5,000 impressions while the transient start up and runnability used 35,000 impressions. The results indicated that "corrosive-resistant" fountain solutions can be used without an unacceptable degradation in performance. These fountain solutions have been shown to produce very little or no piling and dampening system feedback and excellent runnability and print quality when combined with the proper dampening rollers, plates, paper, and ink.