Research And Development Of Water-based Ink For Flexographic Printing

In order to reducing or eliminate the volatile organic compounds (VOCs) which the Environmental Protection Agency wants to reduce and/or eliminate, for ink formulators, one possibility is to create water-based systems, aside from environmental and safety issues, water-based inks have other advantages such as stability and lower flammability ratings. We design for formulating high-level water-based inks especially used in corrugated board.The process of formulating for water-based ink in this paper is to disperse the pigment in the alkali-soluble solution polymer first, and then the emulsion polymer is added to the resulting dispersion. In the first stage, it has been proved that the quality and stability of ink dispersions is highly dependent on the degree and nature of the association between dispersing resin and pigment as well as the viscosity of the medium. It has been further proved that the resin of higher solid lower viscosity, wetting dispersant, and defoamer helping to reducing the medium's viscosity could also affect the dispersing effect. In the second stage, we aimed to hovv to attain excellent end-use performance properties such as printability, viscosity, drying, hardness etc. It has been tested emulsion polymer have higher solids lower viscosity and exhibit typical associated properties, however, considering emulsion polymer's poor or inferior pigment wetting characteristic, in practice a blend of polymer types, depending on required application and specification, have been made ; We also discuss the fine tuning raw material which are generalized as additives, e.g., waxes, dispersant, antifoams. It has be proved that alkali used in saponification and pH adjustment would greatly effect the printabilities, viscosity, drying speed, again in practice a combination of alkalis is used to obtain optimum properties; the activity of waxes at the ink film surface with respect to slip and rub detraction have also been studied and discussed ,it has been tested wax in its correctly dispersion form could provide good slip and rub properties without affect gloss maintenance or resulting in foam stability.So having considered and formulated the component parts of a water-based ink , we have developed successfully w-type high-level water-based ink on porous substrates (corrugated board' Kraft paper).