Digital printing technologies and possibilities for recycling of printed papers: (a comprehensive overview)

Paper plays an important role in digital printing, especially towards quality requirements for this printing process. Digital printing is the hot topic among papermakers in respect with paper recyclability. Paper recyclability depends on inks systems used in digital printing, like toners and liquid inks and its setting mode on the different substrates as well. Possibilities for de-inking are accepted as a part of the whole quality of digital printing technologies. The basic process in paper recycling is the removal of the ink from the printed paper surface. This process is called de-inking. Generally, the de-inking process is based on the separation between hydrophobic inks and hydrophilic paper fibers. When there is a mix of papers, printed by conventional and digital printing systems, the de-inking process does not work properly. Evidentely in this case one must have a very important criterion for graphic papers products-their ability for recycling. Nowadays there is an increased interest in this subject and a huge demand in the digital printing market and towards papers producers. Generally, in every printing process, the interaction between paper (or substrate) surface and colorant is an important factor in determining print quality. This factor also arises the question connected with paper's recycling and utilizing paper waste after printing. Print and paper waste is now valuable and sought as a resource and is in high market demand.