Imagine a printing world without volatile organic compounds... No incinerators, fewer ink housekeeping procedures, and fewer gray hairs about state and federal regulations. Less pH and viscosity concerns. Fewer headaches on achieving thinner ink film thickness...

Ahhh. A world without pollution would be a better world indeed. For now, however, pollution exists—and a VOC fairy godmother does not. Your challenge is to emit the least amount of pollutants while producing the highest-quality product.

In 1991, Union City, Calif.-based Emerald Packaging, manufacturer of printed plastic bags for the produce industry, transitioned its five wide-web flexographic presses from solvent to water-based inks. Kevin Kelly, Emerald's chief executive officer, says that California air quality regulators put pressure on converters in the late 1980s to reduce VOCs. Thus, his business, along with most California converters, eventually switched to water-based inks. In addition to incinerators costing too much, it was thought that water-based ink would catch up to solvent's level of quality.

This past March, however, Emerald returned to solvents. Water-based inks couldn't cut it for Emerald, as produce-packaging competition became as hot as in the snack-food market, and customers demanded eight-color graphics with ink guaranteed not to run off the bag. To promote adhesion, Emerald spent more than $50,000 annually on cross-linkers that were potential health hazards. Also, the converter says that gloss on its clear film was 50 percent less than with solvents, as determined with a 60-degree gloss meter.

One of the last straws for Emerald occurred in 1999 after installing a 64-in., 1,200 fpm, 8-color Windmoeller & Hoelscher Corp. flexo printing press. Even with its superb drying system, the press took longer to dry water-based inks. Emerald wasn't achieving the speeds they anticipated, and all evidence pointed toward returning to solvents. Since making that switch, press productivity has increased 20 percent.

Ironically, Kelly would be happy to be still using water-based inks. "We thought they looked fine," he says. "But we're not our customers, competing on the supermarket shelves."

Although Emerald Packaging is in California—the state with the tightest air quality standards—other states may follow. Steve Utschig, flexographic instructor at Fox Valley Technical College, Appleton, Wis., comments, "Usually what happens in California happens over the rest of the country. The writing is on the wall—we're all going to have to do a better job [of pollution control]." And beware those big-city printers moving to rural areas to escape regulations. Utschig predicts that stricter rules will eventually affect them, too.

With conflicting pressure from the government and customers, what's a converter to do? Luckily, for converters like Kelly for whom solvent inks are the best choice, prices of incinerators have dropped dramatically. With the incinerator, Kelly says his business is in good shape environmentally. It now puts only 8 tons of VOC into the atmosphere, vs. about 25 to 30 tons with water-based ink.

For other converters, water-based ink is the answer to environmental woes. Since his business' inception 10 years ago, Robert Bateman, president of Roplast Industries, Oroville, Calif., has used water-based inks. Extruder and printer of low- and medium-density white polyethylene for bags, Bateman says that, for many applications, there is no objective difference between the quality of water-based vs. solvents. "If you're being told otherwise, you're being misled," says Bateman. He adds that large converters have hoodwinked customers into believing that solvents are superior.

For adhesion, Roplast uses cross-linkers injected directly into the ink, rather than exposing it to the air. This eliminates dermatological risks to employees, and is inexpensive. As a matter of fact, Roplast says that water-based ink is significantly less expensive overall.

No matter how solvent-ink users look at it, Bateman says they create environmental risks that users of water-based inks do not. Although converters like Emerald emit less VOC with incinerators, there is a problem, Bateman explains, "With incinerators, you're converting VOC into carbon dioxide, which isn't recommended from an environmental point of view."

As every converter knows, ink decisions aren't easy. Performance, cost and energy-use issues must be considered. There is no one factor from which to base your decision.

To ease the ink confusion, the U.S. Environmental Protection Agency has partnered with industry to compile a technical report, "Flexographic Ink Options: A Cleaner Technologies Substitutes Assessment." The report, found at www.epa.gov/opptintr/dfe, compares solvent, water and UV inks.

"The best way to identify and prioritize where pollution can be prevented is to map out the entire operation," says the U.S. EPA. Steps where waste is generated include during the ordering of the substrate and ink, ink mixing, makeready/printing, cleanup and shipping. During these steps, lower your pollutants by:

• Keeping containers covered. Decrease your evaporation losses and chance of contamination.
• Monitoring pH and viscosity during press runs. This reduces time and additives needed to optimize print quality. When using water-based ink, Utschig recommends concentrating on pH control, rather than viscosity.
• Labeling ink with dates and using the oldest barrels first. A barrel of expired ink is a barrel of hazardous waste.
• Using computerized ink mixing, blending and dispensing equipment. Computers determine the exact amount of ink and ensure it's mixed right every time.
• Installing enclosed doctor blade chambers. This reduces evaporation and delivers thinner, more consistent ink film and increased print quality.
• Using enclosed cleaning technology. This is quicker and more efficient than hand cleaning; however, Utschig warns that you can damage anilox rolls when removing the bearings.
• Recycling and reusing inks. Emerald's Kelly sends all used ink to a solvent recovery unit and gets back 65 percent of the inks. This cuts his solvent costs by half.
• Achieving thinner ink film thickness. Utschig recommends printing the thinnest ink film possible under control, but also to the proper density. He explains that you must increase the pigment load for thinner ink film thickness. Making the ink thinner and denser means that the ink is more difficult to work with on press because the pigments are solids. "You can put only so much pigment in an ink film. You get the ink film too thin, and now you won't be able to get the color strength you want," Utschig says.

Most important, know exactly how your ink-management system works and how VOCs originate. To better understand your system, communicate with ink suppliers. "Before I open a pail of ink, I want to know the viscosity and pH ranges, the pigment loads and additives, so I work more efficiently and don't destroy the ink," says Utschig. Often, the problem isn't with the ink system itself, but with communication between converters and ink suppliers.

Until the VOC fairy godmother comes along, remember the environment. Kelly sums it up, "Anyone who's concerned about the air they breathe, or the world their children will inherit, must understand and accept that the greenhouse effect is a real factor. We have to work hard to create a sustainable planet."