Impact wetting and contact angle on quality offset press
Dragisa Obradovic, Dragan Obradovic
In this paper the most attention on the influence of surface tension. From the results it can be concluded that reducing the surface tension of wetting solution achieves higher print quality. At the same time reducing the amount of solution, which is transferred to the printing surface speeds up the drying process prints, and prevents the dimensional instability of paper. From the above it can be concluded that there is no solution for wetting the sole function of the refusal of oil paint free surfaces, although it is most important. It its quality composition affects: the printing form which prolongs the life of the rubber rollers that press during regeneration, the color with which it forms a stable emulsion and enables printing without difficulty. The solution wetting its irregular composition, can cause major problems in the press. Changing the pH to acidic or alkaline influences the physical and chemical stability of printed elements and free areas by destroying them, great hardness of water causes the formation of poorly soluble compounds that are deposited on the rollers and offset plates, excessive amount of emulsifying solution causes a color that causes toning printed etc. forms. These are just some of the reasons that require a great deal of attention in preparation for the damping solution. The results showed that the temperature and saturation developer significantly affect the degree of wetting the free surface of the wetting solution. The lowest contact angle, ie the highest degree of wetting is achieved at a temperature of developer than 20Â°C.