Meeting The Demands Of Quality And The Environment
As environmental concerns force paper and press chemistry content to change, ink content is also being altered to stay compatible with the other elements.
Propelled by the dual forces of quality and the environment, ink makers and their suppliers have been under the gun to develop the technology. The changes they introduce, however, take their toll on the products used by the printer. Sometimes this has been good, resulting in superior products. Other times, the environmental changes have resulted in major concerns and problems.
Speaking to Tom Cernera, branch manger of the Metropolitan New York region of Gans Ink & Supply Co., one senses both excitement and trepidation as he talked about the challenges faced by printers and ink makers.
"Never before has it been more critical for printer and supplier to work together," he says. "Making a marriage between ink and substrate has become highly sensitive to the chemistry of both and a victim to changes in the basic process."
Conditions that were routine in years gone by, when all ink had to do was put an image on paper, are no longer so. Paper making has had to meet the demands of the environmental agencies, putting a few new barriers in the way of the ink:
• Titanium Dioxide is now used as a filler for some grades of paper.
• Chlorine free paper produces a new pH level.
• Recycled paper introduces both known and unknown chemistry into the texture of the fibers.
• Hydrogen Peroxide is now being used as a brightener.
Changes in plate chemistry, stemming from direct-to-plate systems, have altered the traditional relationship between plate and fountain solution. This has ramifications in the formulation of the ink.
Add these changes to the movement away from Isopropanol as a major component of fountain solution, and we have critical questions relative to the pH of the various materials and how they come together to make the ink adhere to the paper substrate. Trying to run other substrates adds to the problems.
A New Approach
Contending with these changes in chemistry requires a new approach to ordering inks. Without a sharing of information—a partnership between the paper maker, the printer and the ink maker—the routine work of yesteryear will become the problem of today. Each partner must be concerned with the other as paper is made, ink is formulated and the two are combined on the press with the intrusion of fountain solution.
With lithographic printers facing the need to reduce air emissions and hazardous wastes, while striving for more color and more sophisticated graphics, there have been many developments that have had positive results.
Soy and vegetable oil inks have taken a firm hold. More product lines are embracing the natural oils and replacing the hydrocarbons that were previously standards. Sheetfed process inks are composed of soy and vegetable oils at percentages ranging from 25 to 35 percent. Web inks are higher, with 40 to 50 percent of the formulation consisting of the natural oils. Typical oils come from soy beans, walnuts and corn. The quality of these inks has been excellent and well received by print buyers.
Radiation Curing
Ultraviolet radiation-curable inks and coatings have made inroads into the lithographic market. With printers facing pressures to reduce air emissions based on the solvents and oils inherent to lithographic inks and press washes, UV inks offer a no-solvent material that cures on exposure to a UV lamp. Unless exposed to the UV light, the inks remain liquid and easy to remove from a press ink fountain for reuse. Waste is minimal, and environmental impact is significantly reduced.
Primary products using UV inks are business forms and packaging. Selection of this ink system involves a major modification of the press by the addition of the UV curing lamps and other auxiliary equipment.
UV inks have given the forms printer the ability to use color freely. They have also realized higher productivity and consistent quality. Turnaround time for printing and shipping a job has been reduced to hours. One case cited by Cernera, of Gans Ink, involves an in-plant financial printer that can print, fold and cut a finished brochure and have it shipped within three hours.
The impact of UV has also infringed on coatings. Solvent-based coatings have given way, for the most part, to aqueous and UV-curable coatings, both spot and total coverage.
Printers are cautioned to exercise extreme care in the handling of UV inks. Strict adherence to safety and health precautions will protect the worker from undue exposure to the lights and the chemistry of the UV inks. Regular lithographic inks and UV inks are not compatible, requiring either dedicated presses or extremely well-cleaned machines when switching from one system to the other.
More than ever before, printers are engaging in equipment modifications and work practices to reduce the amount of ink and other chemistry purchased and to reduce press-related wastes. Efforts are being made to reuse or recycle inks, press washes, wipers and other materials and supplies.
Large printers can afford to invest in ink management systems employing computers to control inventory and mix inks. Smaller printers often do not have the finances, personnel or space to employ base ink systems and mixing equipment. However, as technology advances, the investment and physical requirements will diminish and color management systems will be sized for many small- and medium-size shops.
Good management always plays a role no matter how large or small the printer is. Inventory levels should reflect the needs of the plant; you should not store a big collection of cans that rarely moves. Ink returns from the presses should be reused in subsequent jobs, alone or toned to another color.
Purchases should reflect the turnaround time needed by your ink and chemical supplier to meet your needs. Price advantages based on quantity are of little value if the ink or press wash will stand on the shelf for months or years. What comes in as a good product can only leave as a printed product or a waste—possibly a hazardous waste in the case of chemicals/inks.
Computer programs can often be helpful in minimizing changes in inks to meet color standards. Mixing inks by formula to match accepted standards and doing this in the amount needed for the job can provide additional profits for the print shop. Poor color matches only waste time and materials. Too often, they can get into the system and result in rejection of finished products—not the best way to make a good impression on your parent organization.
Where Are We Heading?
Cleanup of inks with fairly heavy-duty solvents is responsible for considerable exposure and concern by the community and the environmental agencies. The air emissions and the hazardous wastes resulting from these cleaning solutions trigger adherence to strict federal and local regulations of all types. But hope may be on the way.
Work is being conducted on strong pigments that will be incorporated with an aqueous base, capable of being mixed to match colors in the same manner as paints in a local paint store. These inks will be capable of being washed from the press rollers and parts by a water-based cleaning solution. Elimination of the typical hydrocarbon solvents from the pressroom washes will keep most printers from having to comply with air and hazardous waste regulations.
The key to this development will be the introduction of new resins that will make it all possible. With considerable research and development of resins to accommodate waterborne flexographic and gravure inks, the design of a water-compatible resin for offset should be feasible.
With one objective firmly resolved, that of the quality of the workplace and the environment, the printer will be able to concentrate on mastering the quality of printing and the satisfaction of his or her customer.
Fred Shapiro is president of P-F Technical Services Inc. and an industry consultant. He can be reached at (516) 935-7241.
- People:
- Tom Cernera
- Places:
- Metropolitan New York