Posted by admin in The standard flexographic inks used in the ink fountain, has approximately 60%-80% ethanol, N-propyl acetate, isopropanol, heptanes, n-propyl acetate. These solvents are VOCs and flammable. Some inks also include dilutant solvents include methyl ethyl ketone, methyl isobutyl ketone, toluene, ethyl acetate, etc. These solvents have been identified as precursors of ground level ozone and health problems for people with respiratory ailments. The Hazardous waste regulations (RCRA) also restrict disposal of these inks as they contain harmful solvents which can be easily ignited. Some of these solvents are classified as “listed” wastes according to the regulatory bodies.
Water-based inks provide an alternative to these dangerous solvents and also a mean to eliminate both pollution and other regulatory constraints on the printer. The USEPA has developed guidelines for state/ local air pollution control agencies to identify those technologies that are acceptable to reduce the impact of pollutants in the process. These guidelines are called Control Technology Guidelines (CTGs). The guidelines set water as the preferred carrier of ink in order to prevent pollution. Hence, whenever a permit application is reviewed, water is considered as the acceptable control technology. The availability and acceptability of water inks depends on substrates that are to be printed on and their end-use characteristics to which the product will be subjected. Paper and paperboard will readily accept water-based inks and coatings. The use of water inks on other substrates such as films and foils differ and require special treatment to make the ink or coatings adhere to the substrate.
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