Miller Magazine Issue: 113 May 2019

73 ARTICLE MAY 2019 Industrial printing inks are increasingly being billed as ‘green’, but what does that mean in reality? How does being green identify with industrial fluids? And are these claims simply paying lip service to those looking to make a positive impact in terms of the inks and make-up fluids they use? There is no clear defi- nition or standard on what it means to be a ‘green’ ink. Manufacturers, in order to keep up with demanding production schedules, require fast dry times and excellent adhesion, which involves the use of solvents such as ke- tones and alcohols. These fast-drying industrial solvents are flammable, volatile, organic compounds (VOCs); the- refore, industrial inkjet inks are starting out with a hazar- dous material that is not necessarily in keeping with the notion of being ‘green’. VOCs are heavier than air, cont- ribute to ground level smog, and some VOCs participate in photochemical reactions in the atmosphere that cause damage to the ozone layer. Even though VOCs are hazardous, they are ever- ywhere – including in gasoline, ethanol used in vo- dka, and even isopropanol (IPA) in medical wipes. Anything that evaporates and contains carbon is classed as a VOC and so we are all in contact with them in some form or another throughout the cour- se of everyday life. WHAT CAN BE DONE TOMAKE INKS ‘GREENER’ There are three approaches to making a ‘greener’ ink; water-based, safer solvent, or Corporate Social Respon- sibility (CSR) goals. The first approach is using water, which is VOC-free. However, water evaporates so slowly that the dry time experienced on production lines will be longer than manufacturer requirements. If there isn’t sufficient time available during the coding and marking process, then the ink would need drying assistance. Ad- ditional energy would be consumed with this approach which negates its ‘green’ benefits. If a water-based solution is not feasible, a second approach would be to utilize a safer solvent, acetone, which is exempt from the U.S. Environmental Protection Agency (EPA) Clean Air Act. Acetone does not participa- te in photochemical reactions in the upper atmosphere; therefore, it does not deplete the ozone layer. Another option is to formulate with ethanol which has low odor and frequently found in the food and beverage industry. Ethanol has been used throughout human history safely for a variety of applications. The last approach involves ink formulations which meet company CSR goals such as no carcinogens, mutagens, reproductive toxins (CMRs), food contact materials, or controlled substances. There is no clear definition or standard on what it means to be a ‘green’ ink. Fast-drying industrial solvents like ketones and alcohols are flammable, volatile, organic compounds (VOCs). Images source: Videojet