Background
Tubed Products is a manufacturer of plastic squeeze tubes and caps for the cosmetic, personal care, pharmaceutical, and household chemical market. Most tubes are sold as empty containers, but some are filled in Tubed Products' Contract Packaging Department. Tubes are first molded from pelletized plastic resin, then printed, coated, and capped in the decorating department. Approximately 40 % of Tubed Products' production efforts are directed at decoration of the tubes with appropriate logos and information as specified by customers.
Before the conversion to ultraviolet curing systems, when thermally cured inks and coatings were used, the decorating lines consisted of a dry-offset printer, a thermal oven to cure the ink, a coater, a second thermal oven to cure the coating, and a capper. These lines were approximately 40 feet in length, and held about 3,000 tubes on their pin conveyors. The two thermal ovens in each line were heated using about 60,000 watts per hour of electricity, and evaporated solvents from the drying of inks and coatings were emitted to the atmosphere. From start to finish, this operation required approximately 40 minutes to produce a printed, coated and capped tube.
Toxics Use Reduction Planning
Tubed Products did not make the switch to ultraviolet inks and coatings all at once. Instead, the firm has moved continuously toward ultraviolet processes over the past 20 years, as these new production technologies have been perfected.
UV curable inks, and the curing systems to use them, first became commercially available in the early 1970s. The potential of these new technologies was first brought to the attention of Tubed Products by American Production Machine Co. of Union City, N.J., a supplier of decorating equipment. In 1973-1974, Tubed Products investigated the benefits of ultraviolet systems and found that they would reduce emissions significantly, require less energy and floor space, reduce waste ink (since UV inks do not dry on the press), and allow them to blend base inks to achieve custom colors. After several trials, Tubed Products purchased a new decorating line using UV inks and thermal coatings. This permitted the firm to do away with solvent-based inks and the solvent emissions generated by their use.
Between 1974 and 1979, several more UV decorating lines were added to keep pace with company growth. Having experienced the benefits of UV ink curing, Tubed Products began working with coating manufacturers to develop and evaluate UV-curable tube coatings. This work came to fruition in 1979, when Tubed Products purchased its first production line to use ultraviolet curing for both inks and coatings. Several more of these integrated ultraviolet lines have been added since.
The acceptance by the industry of UV curing has enabled the design and manufacture of a new generation of tube printing presses, which are known as "on-mandrel UV curing equipment." These state -of-the-art decorating lines enable tubes to be printed, coated and capped while the tube is mounted on the same mandrel, thereby eliminating the need for the tube transfer mechanisms and creating fewer rejects. They also occupy less floor space than the previous UV curing lines since the printing, coating and capping is done on one piece of equipment.
Toxics Use Reduction Modifications
The conversion to UV-cured inks required new procedures for color matching and measurement, and the later introduction of UV-cured coatings required measurements of coating surface friction, permeation, flexibility and non-yellowing properties.
The addition of new, higher-speed presses required more sophisticated training programs for both machine adjusters and maintenance personnel. One particularly critical issue has been the development of procedures for the use and care of the UV lamp systems. However, after initial training, very little follow-up has been necessary.
Results
Reductions Achieved
The gradual conversion from thermal to ultraviolet curing has proven beneficial in many ways. Each UV decorating line occupies approximately one third the floor space of a comparable thermal line, and requires only about one-fifth the energy (12,000 watts per hour) to operate. While the thermal lines required 40 minutes to produce a tube, the newest high-speed on-mandrel lines do the job in five minutes. Since the UV inks and coatings contain no solvents, worker exposure to toxic and hazardous solvents has been reduced significantly, and significantly less solvent emissions are released to the environment than would be if thermal systems were still in use. Tubed Products believes the continued use of thermal cure inks and two-part epoxy coatings could have compromised their long-term compliance with air emissions standards.
Economics
Since the changes were made gradually, and since production rates are far higher than they were when thermal curing was still in effect, Tubed Products never made any determination of the costs or savings realized, or the reductions in emissions which have resulted from the change to UV-curable systems.
The firm believes that this early conversion to UV ink and coating systems has been an important factor contributing to its growth in the industry, helping it to become a low-cost producer and the largest U.S. supplier of plastic squeeze tubes.
“We appreciate the TURA program as it encourages employers like Polartec to seek alternatives that are environmentally friendly and that make economic sense. TURA can help businesses gain an edge from continuous improvements. The associates and management of Polartec recognize their responsibility to function as good corporate citizens by operating under an Environmental Policy dedicated to environmentally conscious manufacturing. Our Policy is predicated on the belief that a healthy environment can coexist with a strong manufacturing environment. We are sensitive to the environmental concerns of our associates, customers, neighbors and community, and believe in the adoption of technical, institutional and social policies that will reduce the ecological impact of manufacturing. Our commitment is to continuously reduce energy consumption and emissions, to minimize waste, and to increase the recycling of resources.”
The time required for cleaning fabric was reduced by 16%, a significant dollar value for the company that also includes efficiency and savings in resources. Chemical use costs were reduced by 10%, based on purchase price and amount used. Utility savings, steam and water, were reduced by 12%. Although some of the reduction in total quantity of use is due to lower levels of production, Polartec has seen an overall 25% reduction in its NaOH use per yard of fabric processed. Finally, the company is also exploring alternatives to acetic acid, which could provide additional toxics use reductions and economic benefits.
Energy Conservation
Polartec initiated a number of energy efficiency programs over the last four years. The first project was the installation of a high efficiency lighting system throughout the plant. This new system provided 20% more light with half the electrical demand. The cost of the investment was $726,000, which resulted in a cost savings of $350,000 per year. Including $200,000 in rebates from its energy provider, the payback was only 18 months. The company also replaced its air compressors with more modern equipment. This saved close to $200,000 in fuel costs, with a payback period of two years. Polartec also developed an Energy Management System (EMS). As part of the EMS, the company:
- Installed variable frequency drives on fans, which saved more than $400,000 per year and paid for itself in just over a year;
- Steam pressure was reduced from 100 to 60 psi, which saved an estimated $46,000 per year.
Polartec’s combined savings for its energy conservation benefits is just under $1 million per year. While the cost of making these changes was $1.5 million, the company has already been paid back from the cost savings generated by the projects. In addition to the savings, Polartec’s carbon footprint was reduced by about 21%, with nearly 12,000 tons of CO2 reduced since 2006. The use of recycled yarn reduced CO2 emissions at the site of their supplier by an estimated 27,000 tons. Finally, Polartec is currently working on the installation of a hydropower unit that will produce an estimated 175 kW of electricity, and is performing an analysis of using a backpressure steam turbine generator to generate 625 kW of power.
Recycling Efforts
Polartec continues to expand its recycling efforts. The company uses Repreve 100 yarns, from Unifi Manufacturing. Repreve 100 yarns are made from 100% postconsumer recycled plastic bottles. Polartec used in excess of 30% Repreve for 2010, with a goal of 40% Repreve in 2011. Using the recycled materials allows the company to reduce the need to use virgin synthetic fibers and keep more than 21 billion plastic bottles from landfills.
Published 2005