Das8. UV‐Cured Supermatt Surfaces With Low Migration

Acrylate-based varnishes or printing inks are usually cured by ultraviolet (UV) or electron beam irradiation. Some manufacturers of radiation curable varnishes and printing inks offer so-called low migration series. Usually electron beam cured varnishes and prints show lower migration, and food packaging compliance is easier obtained than for UV-cured materials. UV-cured coating can be easily distinguished from the electron beam cured one by the high concentration of migrating photoinitiator molecules, whereas the acrylate monomer migration shows comparable values. DirectCure post-irradiation of UV-cured prints and varnishes proved to be an efficient tool for migration reduction. Microfolding is the result of a surface area increase after surface curing. The excimer-cured layer is folding up forming the characteristic microstructure. Using precuring, excimer matting and final curing, inks, and varnishes on sheet or panels can be also finished.