The Influence of Fountain Solution Additives and Blanket Swelling on the Linting of Newsprint

摘要

It is evident that the composition of the fountain solution can have a decisive effect on linting, but that the effect is not the same for all types of paper. It is not possible to improve the runnability - to increase the time between washes - for all grades of paper through the use of a particular fountain solution additive. A test must be made in each case to determine the best combination for a specific application. The quantity of fountain solution can affect the linting. An increase in the amount of fountain solution reduces the stickiness of the blanket and therefore decreases the linting but large quantities of fountain solution additives lead to an increase in the linting. Paper grades that contain recycled paper have a lower tendency to linting, due to the better cleaning and sorting techniques compared with virgin fibre grades. With increasing age, the smoothness and stickiness of the blanket surface increase and this negatively influences linting. Swelling as a result of the effect of cleaning agent can alter the surface characteristics of a blanket, and different cleaning agents can affect the swelling of the blanket to differing degrees. The packing height of the blankets also has a major influence on linting. Too much or too little pressure may result in linting because of deviations from a precise rotation. The packing height should be essentially the same for all cylinders and the blankets should also display the same surface properties. If there are deviations from a true rotation, deposits start to appear on the blanket in or opposite to the direction of printing and this can lead to an uneven waviness in the printing.