Water Based Inks for Flexographic Printing

The Clean Air Acts have identified solvents typically used as vehicles in flexographic inks as precursors of ground level ozone, a major cause of health problems for people with respiratory ailments. Hazardous waste regulations (RCRA) restrict disposal options for all wastes mixed with solvents from these inks that are easily ignited. Some of these inks are classified as listed wastes if specific solvents are part of the composition. A typical flexographic ink for film substrates, as applied in the ink fountain, has approximately 60%-80% of its weight in solvent such as Ethanol, N-propyl Alcohol, Isopropanol, Heptane and n-Propyl Acetate. These are all VOCs and flammable. Some inks and diluent solvents include Methyl Ethyl Ketone, Methyl IsoButyl Ketone, Toluene, Ethyl Acetate, etc., all of which are listed as (F) wastes. Waterbased inks provide an alternative to these solvents and a means of eliminating both pollution and many of the regulatory constraints on the printer.Ope