Coming, maybe, to your state: air-quality rules mandating the use of press solvents containing no more than 100 grams of volatile organic compounds (VOCs) per liter.
Coming, perhaps, to your pressroom: problems you didn’t anticipate with s-l-o-w press washups, funky residues, and strange chemical side effects such as “tearing” (as in weeping) rollers.
The source of it all is California’s South Coast Air Quality Management District (SCAQMD), a regulatory region that confronts its printers with some of the most stringent emission-control restrictions in the U.S. SCAQMD has been phasing in the 100-gram limit for nearly 10 years, ostensibly in partnership with printers as well as manufacturers of pressroom chemistry.
In January of this year, the limit went into effect for most offset lithographers in SCAQMD’s 10,000-square-mile jurisdiction. Taking their cue from the “District’s” initiative, regulators in other states reportedly are eyeing 100-gram limits of their own.
Printers in Southern California already know what to expect from low-VOC solvents. Those who attended a panel discussion on the SCAQMD rules today (April 28) at the Web Offset Association’s “Offset and Beyond 2008” conference got an uneasy foretaste. The panel, moderated by Jim Leitch, CEO of Braden Sutphin Ink Co., traced the evolution of the SCAQMD mandate and described, in blunt terms, the difficulties that many plants are experiencing as they struggle to comply with it.
VOCs are a key ingredient of smog, a perennial public health concern in SCAQMD territory. Gerry Bonetto, vice president of government affairs for Printing Industries of Southern California, said that in 1999, the agency set a 2005 target for the adoption of low-VOC press washes by offset and screen printers in the region. In the interim, SCAQMD sponsored a technology review that was supposed to give printers and solvent makers a voice in the program’s implementation.
The agency’s tendency to treat an industry advisory committee as a “rubber stamp” soured feelings about the project, Bonetto said. Nevertheless, 20 of Southern California’s leading printers took part in field tests of solvent formulations proposed by SCAQMD’s technical division.
Some were soy-based. Others were made with acetone. All of them, said Bonetto, proved so unsuitable that SCAQMD pushed back the deadline by a year and a half and permitted printers to work with 500-gram-per-liter products in the meantime.
Problems continued to crop up even at the higher level, but SCAQMD, undeterred by protests, imposed the 100-gram limit in January for offset litho presses using either manual or automated washup. Printers running presses with UV (ultraviolet) or EB (electron beam) curing systems have until next year to comply.
Calling the phase-in a “10-year fight,” Bonetto said that Wisconsin, New Jersey, and Texas are among the states that probably will adopt the 100-gram standard in their air-quality management areas.
He conceded that low-VOC solvent do what they’re intended to do—clean ink from offset blankets. But some of the experimental concoctions did other things as well, such as producing “drips all over your print jobs” from the oily soy base of the wash. In one trial, said Bonetto, the formulation all but “destroyed the press.”
Dr. Mark Bohan, vice president of research and technology for PIA/GATF, said that the principal downsides of low-VOC solvents are slower cleaning times; lack of evaporation from rollers and blankets; and residues left on blankets after washup. Of the three negatives, the most immediately apparent is the slowdown in productivity. Printers used to working with 800- and 900-gram solvents, he said, could see a 30% to 300% increase in blanket washing time when they switch to the 100-gram products of the kind that SCAQMD has mandated.
According to Bohan, the potential problems don’t stop there. After treatment with low-VOC formulas, blankets may swell. Ink tack can break down. The flow of ink through the press may be compromised. On presses with automatic blanket washup systems, additional manual cleaning may be necessary. Running with UV inks raises all of these issues to an even higher level of difficulty.
Ed Papson, a formulation chemist who administers environmental and regulatory matters for press chemistry supplier Prisco, added low flash points and the risk of spontaneous combustion to the list of drawbacks. Noting that there are many formulary criteria to satisfy in developing a compliant low-VOC solvent, he said Prisco extensively tests the effects of these products not just on blankets, but on any press component with which they could interact.
There have been some surprises, Papson said. Low-VOC solvents can react adversely with the metal parts of automatic washup systems. Plate metal also can be affected, as can the integrity of roller compounds. In one test, a roller appeared to shed tears not of grief, but of plasticizer—an ingredient pulled to the surface as droplets in an unwanted reaction with the solvent.
Larry Lester, chief operating officer of Lester Lithograph Inc. in Anaheim, joined the SCAQMD-sanctioned testing program in 2005. It didn’t take long, he said, to notice that blanket residues left behind by the low-VOC products were bad news for ink-water balance, leading to issues with toning, color variation, and ink misting. He fixed some of them by resorting to that time-honored solution, pressroom home brew: in this case, vinegar and water added to the solvent, mitigating its ill effects.
He also spoke of seeing a double or triple increase in washup times as a result of working with “the stubborn stuff.”
Noting that printers in Southern California have been “forced” to use low-VOC products, Lester urged printers in other parts of the country to get ready to face the same obligation. “Start testing now,” he said, by seeing what happens when a 500-gram-per-liter solvent is substituted for a blanket wash with a higher VOC content.
Lester found one favorable thing to say about low-VOC solvents—indeed, the only compliment paid them by any member of the panel. They’re economical. He said that a while a gallon of 100-gram solvent, at $20 to $22, is more expensive to purchase than a $13 gallon of an 800-gram solvent, the low-VOC product is cheaper to run because only about half as much has to be used.
By the middle of next year, concluded Bonetto, printers in other parts of the country could be telling stories like Lester’s about their own problematic experiences with low-VOC solvents.