Water Based Printing
Water-based ink printing systems utilize either dyes or pigments in a suspension with water, where water acts as the primary solvent. But water based does not mean that water is the only is the only solvent, many water base inks contain “co-solvents” which may be petroleum-based solvents and contribute to a VOC content of the ink. Evaporation of the water from the ink is required to set or “cure” the ink. Curing is typically assisted with the use of electric or gas operated dryers that require energy and contribute to the emissions of this process. Non-water based solvents are typically added to decrease the time and heat necessary to cure the ink on the fabric. When catalysts or hardeners are added they dramatically reduce the shelf life of the ink. Nearly all water-based inks, like all other inks, are industrial chemicals. Water-based inks are required to be treated and handled by the same local, regional, and federal laws and regulations pertaining to employee training, storage, handling, and disposal as screen printers as any other kind of textile printing ink. Do not assume that because they are waterbased that they can be disposed of simply. Water- based inks can be cleaned up with water. Some water-base inks or ink additives may still contain chemicals that are suspected or known to be human carcinogens. Review the Materials safety Data Sheet (MSDS) sheet on any ink and ink systems used to determine if this is the case with any of the inks you use. Water-based printing systems often contain several auxiliary chemicals that are added to improve the performance of the ink. Compounds are added to assist in textile wetting, thickeners or dispersants might be added to modify flow and defoamers may be added to control foam. These ingredients may or may not be listed in the Hazardous Components
Pros • No PVC • No or lower VOCs • Fewer chemicals/solvents involved in clean-up
Cons • Can use more energy to power oven or heaters used to evaporate water • Can still have toxic ingredients and additives
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