Case Study 1

Replacement of Hazardous Material in Wide Web Flexographic Printing Process

Kranz, P.B., T.R. Williamson,and P.M. Randall
USEPA RREL Project Summary. EPA/600/SR-93/149. 1993.

A wide web flexographic printing firm substituted water-based inks for solvent-based inks when manufacturing flexible packaging using plastic sheet substrates (e.g., plastic bags for bread). The project objectives were to evaluate the technical feasibility, economic effect, and resulting change in VOC emissions achieved by the substitution. The technical evaluation was to quantify the reduction in both volatile and liquid-phase solid hazardous wastes. Reduction of VOC emissions by switching from the use of solvent-based inks to water-based inks required several equipment modifications and a feedstock substitution, including dryer capacity enhancement, press roller modification, ink handling equipment upgrade and installation of an in-line corona treatment system. Water-based inks containing 72.5 percent less VOC were used in place of, and combined with, traditional solvent-based inks.

For each percent increase in water-based ink use, VOC emissions were reduced 14 lb. This was based on usage of ~2250 lb. of solvent-based ink per week, resulting in VOC emissions of about 1570 lb. Typically the substitution did not adversely affect product quality or non-hazardous scrap waste generation. An average reduction of 95 percent of liquid F003 waste from waste ink and cleaning solvents resulted from operational practice changes and employee training.

The economic evaluation was completed by calculating the costs of press modifications, ancillary equipment, waste disposal, inks, and solvent. The project had a positive net present value of $39,165 and a payback period of 2.5 yr, based on 21 percent utilization of water-based ink; 100 percent utilization of water-based inks would yield a payback period of 0.54 yr.

Additional benefits from reduced VOC emissions and liquid hazardous waste have been improvements in the workplace resulting from the switch to water-based inks include reduced indoor air pollutants, reduced handling of hazardous solvents, and the appreciation by company employees of the need to make a conscious effort to further reduce waste generation.

Case Study 2

Achievements in Source Reduction and Recycling for Ten Industries in the United States

J. W. Tillman
USEPA RREL Report. EPA/600/2-91/051. 1991

Amko Plastics, Inc., in Cincinnati, Ohio is a decorative printer for packaging of consumer products, retail store packaging and industrial packaging employing approximately 280 people. By switching from solvent-based inks to water-based inks, they have minimized their volatile emissions by an estimated 88 percent. The reduction of alcohol solvent vapors has improved the ambient air quality of the press room.

The following process changes and modifications were evaluated and implemented:

• Control of pH of the ink to maintain viscosity and print quality.
• Modification of dryer heads between successive color print stations to direct heated air onto the printed film (increased drying capability for water-based inks).
• Redesign of ink metering systems for handling a higher strength ink and thinner application.
• Replace metal anilox rolls, which were having their wear-life drastically reduced, with more expensive ceramic rolls.
• Switch the fountain roll surface material to a harder durometer rubber to improve wear-life with ceramic anilox rolls.
• Develop systems and equipment to inversely vary the percentage of resin `slip additive' blended into the resin as the film was being extruded to allow high speed printing.
• Installation of larger corona treating systems for electrostatic treatment of the film surface at the higher surface tension required for water-based inks.
• Switch to foam cushion `sticky-back' from conventional `sticky-back' to compensate for the additional pressure needed with water-based inks to achieve impression.

The major costs incurred by Amko from 1984 to 1987 (exceeding $2 million) have today resulted in the ability to print with quality and productivity at the same level as U.S. solvent-based printers.

Case Study 3

Solvent Recovery from Flexographic Printing Inks

D.C. Crump

Pollution Prevention: Proceedings for the Conference "Waste Reduction - Pollution Prevention Progress and Prospects within North Carolina. Ed. Gray, et.al.

Rexham Corporation installed a two-stage distilling process at their flexographic printing plant in Greensboro to recycle used solvent. A special room was built to house the stills and all appropriate safety features were incorporated. They have found that uncut ink cannot be distilled due to charring. This onsite distillation has reduced the amount of hazardous waste to a level that changed the status of the generator to small generator.

Case Study 4

Venture Packaging, Charlotte NC.

Case Summaries of Waste Reduction by Industries in the Southeast
Waste Reduction Resource Center for the Southeast, Raleigh, NC, 1989

Venture Packaging undertook a project to replace solvent-based inks, coatings and adhesives with water-based materials to reduce emissions and the volume of ignitable waste generated. Since implementing this program in 1980, emissions have been reduced by approximately 55 percent. An additional 15 to 20 percent reduction appears possible with further application of water-based materials. The greatest success has been achieved in adhesives. Water-based adhesives are now being used for almost all production. Ink development has been more difficult and has varied with the substrate to be printed. Laminating inks have been more successful than surface-print inks.

Capital expenditures have been minimal, but experimental costs have been incurred. The alternative, the addition of incineration equipment, would be very costly.

Case Study 5

Water and Ink Waste Reduction at F.C. Meyer Company

Toxics Use Reduction Case Study
Massachusetts Office of Technical Assistance -C101-2, 8/93

F.C. Meyer Company, a Lawrence, Massachusetts cardboard box manufacturer and printer, employs 200 people operating eight printing presses over three shifts/day, five days/wk. In 1989, F.C. Meyer switched from solvent-based inks to water-based inks, and reduced its VOC emissions from 280 tons per year to less than 1,000 lbs.. per year. Performance quality was unchanged and the regulatory workload was reduced substantially. In 1992 they began to seek further waste reduction opportunities in the area of press cleaning procedures. Through employee training, and improved washing practices, the company was able to reduce wastes from 10 drums of hazardous waste to 2 drums of nonhazardous waste per week. This reduction was achieved by draining and scraping as much ink as possible before washing, and minimizing the amount of water used.

In addition to reducing the volume of wash water used, the company asked its supplier to deliver black ink with 10 percent reduced water content. Waste water was added to the black ink with no apparent effect on the color quality of the ink. The waste water can also be added to other colors, such as gray, in smaller amounts than when added to black ink.

Reductions achieved

Solids in spent wash water were reduced from more than 30 percent to 13 percent. The volume of water used decreased by 35 percent; about one pint of water is now used each time a press is washed. By reusing most of the wash water, waste disposal has decreased from 10 to 2 55-gallon drums per week. The 55-gallon drums of waste cost ~$100 each to dispose. Implementing the reuse of ink waste water has reduced the yearly cost of waste disposal from $52,000 to $5,200.

Case Study 6

VOC Reduction at Hampden Papers, Inc.

Toxics Use Reduction Case Study, C201-1, 8/93
Massachusetts Office of Technical Assistance

Hampden Papers Inc. of Holyoke, MA, reduced emissions of VOCs by 97 percent over a ten year period by using new aqueous based acrylics developed by I.C.I. Resins US of Wilmington, MA. Hampden is a 180-worker specialty manufacturer of converted paper, film, foils, and boards with 64 production lines in a 300,000 ft² facility. In the 1970s they elected to pursue reduction at the source rather than emission control. The company implemented a new coating system using non- and low-VOC inks and coatings and now uses gas oven drying and electron beam curing where necessary. They have not had to purchase VOC collection and control equipment.

Hampden found that I.C.I. acrylic copolymer resin inks and coatings have fast drying characteristics. Thermally sensitive films and coatings are cured in one of the first Energy Sciences electron beam units ever installed. Infrared technology is also used to improve drying. The aqueous products have demonstrated excellent clarity and resolubility on the press.

Over a 10-year period, Hampden has reduced annual VOC emissions at its facility by 97 percent, from over 420 tons to less than 20 tons. VOCs emitted per unit of product dropped from 8.15 pounds to 0.22 pounds. Hampden increased total production by 21 percent in the same period and has realized significant savings in fire insurance premiums. The reduction of VOCs has resulted in lower compliance costs, savings on insurance premiums, and a safer work environment.

Case Study 7

A (UV) Cure That's Eco-Friendly

Graphic Arts Monthly, November 1991:S6

James River is a marketer and manufacturer of consumer products, food and consumer packaging, and consumer-related communications papers. Their product lines include brands such as Northern bathroom tissue, Brawney paper towels, Dixie cups and plates, Monterey magazine paper, and the Quilt-Rap sandwich wrap. Sales for 1990 were $5.4 billion.

In 1975 James River began using UV-cured inks, and by the mid-1980s a significant process expansion was undertaken. UV-cured inks are used in the converting process. They create the opportunity to combine multiple steps into an in-line process. These inks dry instantly and are more energy efficient, but generally cost more than conventional inks.

Case Study 8

Tubed Products, Inc. Use Reduction Case Study

Office of Technical Assistance, Commonwealth of Massachusetts
Case Study No. 31. Nov. 1995

Tubed Products, Inc., of Easthampton, MA is a manufacturer of plastic squeeze tubes and caps for the cosmetic, personal care, pharmaceutical, and household chemical market. About 40 percent of their production is decoration of tubes with specific logos and information specified by customers.

Tubed Products made the switch to ultraviolet inks and coatings over a period of 20 years. Trials with their first UV decorating line in the early 1970s showed that UV systems had significantly reduced emissions, required less energy and floor space, reduced waste ink (since UV inks do not dry on the press), and allowed them to blend base inks to achieve custom colors. In 1979, after working with coating manufacturers to develop and evaluate UV-curable tube coatings, they purchased their first production line that used UV curing for both inks and coatings. Later, `on-mandrel' UV curing equipment was designed and manufactured that allowed tubes to be printed, coated, and capped while mounted on the same mandrel, thereby eliminating the need for tube transfer mechanisms.

Conversion to UV-cured inks and coatings required new procedures for color matching, measurement of surface friction, permeation, flexibility, and non-yellowing properties. The addition of high speed presses and UV lamp systems required additional training.

The benefits of switching to UV curing have been space and energy savings; each line occupies about one-third the floor space of a comparable thermal line and about one-fifth the energy (12,000 watts per hour). Thermal lines need about 40 minutes to produce a tube, while the high-speed on-mandrel lines take only 5 minutes. UV inks and coatings contain no solvents, reducing worker exposure and environmental concerns significantly. Although the firm has not calculated the exact cost savings, they believe that switching to UV systems has been an important factor contributing to its growth in the industry, helping it to become a low-cost producer and the largest US supplier of plastic squeeze tubes.

Case Study 9

How We Anticipated and Corrected Problems When Converting to Water

F. Lamar Jones, Label America, Inc.
Flexo, July 1990

In the beginning, all press operators were very experienced, but only with solvent-based inks. During the transition from solvent- to water-based inks, customers were demanding better color matches, more consistency from run to run, and much improved light-fastness. Suppliers were not providing inks that were base color consistent, and service was poor. Other flexo converters were beginning to switch to water inks, so we looked for a supplier that would commit to us, providing both service and quality, and made the switch.

We chose one press and one pressman to experiment with the water-based inks. That minimizes disruption in the pressroom, and allowed us to "work off" the inventory of solvent-base inks. We had to make adjustments in press speed, wash-up sink, substrates, tools, and ink additives.

Press speed: We routinely run water-based inks at 400-500 feet per minute, on both gloss and uncoated stocks. We have found that movement of air is as important, if not more important, than heat, in the drying of water-based inks.

Wash-up: Water-based inks require a mild soap solution for wash-up. In order to avoid contamination of the inks with this solution, a custom wash-up sink was built. It is centrally located in the pressroom and large enough to accommodate the ink pan, bucket and pump. At the end of the job, ink is drained back into the ink container. Residual ink in the pan, bucket, and pump go to the sink where the wash solution circulates through until they are clean (about 3 minutes). Disposable pans are available, which would also reduce wash-up time.

Substrates - paper vs. film: Label America, Inc. specializes in EDP labels, both pinfed and sheetfed, so the bulk of the printing is on uncoated paper, which may be rough. Ink coverage can be improved with ink additives. Our experience has been that with proper primer and specially formulated inks, we can effectively print on films and foils with excellent results.

Tools: With the switch to water-based inks, we had to make more use of Zahn cups and pH meters to maintain the ink quality.

Ink maintenance: Replenishment is added as needed, and the pH meter is used often.

Ink additives: Slow, medium, and fast dry reducer, print cleaning additive, glycol, ammonia, extender and color boosters are all being used to improve print quality

Computerized ink mixing: This is among the most significant changes for Label America, Inc. It has paid for itself several times over within a year. It has reduced raw material purchases by allowing the company to purchase only base colors. It allows for effective mixing of even very small batches, reduces mixing time to about 3-4 minutes, and allows us to keep much better record of ink inventory.

Water-based inks are better environmentally and for human health - (fire hazard, solvent fumes, ease of disposal.) Inventory has been reduced by over half and sales have doubled. Insurance costs have decreased. Color consistency and colorfast characteristics have improved.

Case Study 10

The Spirit of Innovation

Martha Ortmann
Boxboard Containers, pg. 32-33

Lawrence Paper decided to retrofit its printing stations with a new, more efficient doctor blade system. The original open system was too costly in terms of ink consumption and contamination. Printco is a company that does retrofittings on printing presses. The retrofit involved many weeks working with the intricacies of the press, and engineering and redesigning the plate system. The new system saves ink and improves print quality. The blades are changed more often, and blade pressure is determined and adjusted automatically. Laser engraved anilox rolls are used as opposed to mechanically engraved ones.

Advantages of the new system: the old system used 30 to 40 lbs. of ink per ink change whereas the new system requires only 8 lbs. which reduces ink usage and volume of ink contaminated; blades can now be changed in 20 minutes versus an hour with the old system; the new system is detachable, making repairs easier.

Lawrence Paper recycles 100 percent of the water used in the printing process.

Case Study 11

Waste Minimization Assessment for a Manufacturer of Product Carriers and Printed Labels

Waste Minimization and Recycling Report, 1994
Government Institutes, Inc.

A plant manufacturing printed polystyrene packaging labels and high density polyethylene (HDPE) product carriers with over 400 employees produces 8 billion labels and over 500 million product carriers each year.

Wastes produced include volatile emissions (from the polystyrene extrusion process from the blowing agent Freon-22TM and impurities in the polystyrene); photoprocessing wastes; plate washing wastes (butanol/perchloroethylene solvent mixture), both liquid and volatile emissions; damaged or obsolete plates; solvent inks; press washing solvents (liquid and volatile emissions); defective product; wastes from the thermoforming and cutting process.

Solvents are recovered with two large distillation units and reused in the plant; all extrusion wastes that have not been inked are reground and reworked onsite; off-spec inks and surplus inks are reworked; ink runs are scheduled to allow light-to-dark transitions in the printing trays; wash-up solvent is recovered onsite for reuse.

The economic savings from the waste minimization opportunities implemented result from the need for less raw material and from reduced waste treatment and disposal. Additional waste minimization opportunities are listed in the case study.

Case Study 12

Thinking Positive about Compliance Pollution Prevention through Process Improvement

Fred Shapiro
Polymers, Laminations & Coatings Conference: 315-320
1991

A flexographic printer of stationery items and coating paperboard with overall solid colors was concerned with disposing of wastewater. Corporate engineers estimated the volume at 50 gallons per day, but further inspection revealed that one press operation alone was generating about 1,000 gallons per week. Examination of the printing process also revealed poor scheduling, untrained personnel, unsound practices in sequencing of colors, inadequate accessory equipment to facilitate efficient changes of color, and using free running water to clean parts during changes. A wastewater treatment unit was installed at a cost of $40,000 - $50,000.

Added ink pans and ink pumps helped make color changes more efficient. A cleaning tank was purchased so parts could be cleaned while the press was running, reducing the length of time it took to change colors and the amount of water used. Improved scheduling of colors eliminated some of the cleanup as well. Savings in downtime alone amounted to over $100,000 per year.