Saturday, October 18, 2008

For great color on press, go green.

Occasionally, I'm going to write on topics I'd like to learn more about as an incentive to research them in the first place. Today, on my birthday, I'm going to be lazy and share an article I already researched and wrote for International Paper. Having just gotten back from San Francisco, all things green and sustainable are on the brain. The audience for this article included merchant paper companies and commercial offset printers. My intent was to inform them of environmentally-sound choices they may make regarding inks and varnishes. The article was published July 2007 in Link, a bimonthly publication that is designed, written, produced, and circulated by International Paper.

Sustainability, as defined by the World Commission on Environment and Development, is development "that meets the needs of the present without compromising the ability of future generations to meet their own needs." The concept of sustainability can seem complicated at first, but when boiled down to basic principles it is quite simple. Every human activity consumes resources from the planet and produces waste that the planet must somehow absorb; this is referred to as an ecological footprint. Having recently taken a quiz on my personal footprint (analyzing food consumption, mobility, shelter and goods/services used), I am glad to know that I hit the average for a U.S. citizen but shocked to find that, were everyone on Earth to live a lifestyle like mine, we would need 5.5 planets!

In an atmosphere of rapidly expanding social and environmental responsibility and awareness, many stakeholders in the graphic communications industry are modifying their business practices to conserve resources and reduce their footprint on our planet. One way that commercial printers can do this is to look more closely at the chemicals they put in their presses. Specifying agri-based inks and water-based varnishes for sheetfed and web presses over petrochemical varieties, for example, can significantly reduce the amount of volatile organic compounds (VOCs) released into the environment. Beyond that, there are other types of inks that can be used to replace hazardous, petroleum-based inks. Following is a short list of inks that are available to commercial printers today.

Petroleum-based inks. Petroleum is not considered sustainable and is not a renewable resource. They contain relatively high levels of VOCs that are emitted into the air; this can be an irritant to press room employees. They also contribute to the formation of smog. They do, however, dry more quickly than vegetable-based inks.

Heavy metal and metallic inks. Known carcinogens such as cadmium, chromium, and lead have been replaced with carbon-based substitutes, but many colors still contain heavy metals that can contaminate soil and groundwater when leached into the environment. Typically, metallic inks are not easily recycled or mixed with other inks. Earlier this year, Sun Chemical did launch Metal-Eco, a vegetable-based sheetfed offset metallic ink that they claim is the first on the market completely devoid of mineral- or petroleum-based oils. They are available in the full range of Pantone metallic colors from PMS 871 to PMS 877.

Vegetable-based inks. A good alternative to petroleum-based inks, these products are made with renewable and biodegradable resources such as soy, cottonseed, vernonia, sunflower, tung, linseed, and canola oils. Soy-based inks can contain anywhere from 20% to 100% soy oil, and the balance is made up of petroleum. Because there is a percentage of petroluem, vegetable-based inks do emit VOCs; however, their emission rates are much smaller than a purely petrochemical ink. It is important to contact ink manufacturers when specifying a vegetable-based ink to insist on a low VOC rating.

There are several advantages to using agri-based inks:
- Less tendency to skin over in the ink well
- Soy-based inks tend to work well with recycled paper because they adhere more effectively and do not pick out the fibers of the paper
- You get brighter colors
- They permit greater latitude in ink-water balance and provide more coverage per pound of ink

Unfortunately, there are also drawbacks. Soy and other vegetable oils cannot be used for heat set inks because the drying time is considerably slower than that of a petroleum-based ink. Also, the vegetable oil in the ink is a renewable resource, but the pigment suspended in the oils can potentially be a toxic ingredient. Certain colors require heavy metals that are hazardous such as zinc, barium, and copper; for an even "greener" vegetable-based ink, specify a color with no heavy metals.

UV inks. When UV inks are printed they are exposed to ultraviolet light and immediately dry to a solid film. While these inks can be difficult to recycle, this process releases no VOCs into the environment.

Varnish, aqueous and UV coatings. Aqueous coatings are more environmentally friendly than petroleum-based varnishes because they emit fewer VOCs, can be recycled, and do not require potentially hazardous solvents for clean up. As with UV inks, UV coatings can be difficult to recycle but emit no VOCs because they cure instantly.

Recycled inks. Waste ink is generated through on-press color changes, press cleaning and poor ink management; these practices encourage ink drying and skinning. Printers can blend leftover four color process inks to produce black. This produces a deeper, richer black since it is built out of more than one color. They may also mix non-contaminated excess ink with virgin ink of the same color. Otherwise, leftovers can be returned to ink distributors for recycling.

Toner for digital presses. Toner cartridges are recyclable, but toner used in such equipment as laser and ink jet printers are petroleum based. The Battelle Memorial Institute in Columbus, Ohio, has partnered with the Ohio Soybean Council (OSC) to develop a more sustainable, soy-based option for copy machines and computer printers. They are currently working on potential marketers to bring the product to consumers this year.


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