1992 Award Winners

• Zytec Corporation
• The John Roberts Company
• Sheldahl
• IBM Rochester

A manufacturer of electronic circuit boards, Zytec recognized the need to reduce its use and release of chlorinated fluorocarbons (CFCs). CFCs diffuse into the upper atmosphere and destroy the protective ozone layer. The resulting increase in ultraviolet radiation is capable of causing skin cancer, eye cataracts, suppression of the immune system, and crop damage. CFCs are also greenhouse gases. In light of these consequences, Zytec management set a goal of complete elimination of CFCs by 1991.

Zytec used CFCs to remove soldering fluxes remove metallic oxides and other contaminants, thus improving product reliability and quality of solder joints. However, if solder residues are not removed, they lead to corrosion and eventual failure of the circuit boards. In order to eliminate the use of CFCs for cleaning, the company looked at alternatives to both soldering and cleaning. The alternatives included water soluble fluxes, inert gas soldering and alternative cleaning solvents.

Zytec elected to convert to the use of low solids soldering fluxes (LSFs), which have much lower levels of chemically active substances and are free of more corrosive elements such as chlorine. LSFs leave a relatively benign residue on the circuit board and allow for standard soldering with little or no cleaning afterwards. In addition, LSFs can be immediately utilized with existing equipment. Because their use eliminates the need for any cleaning equipment from the assembly line. This simplified the process and eliminated opportunities for error. With the cleaning step deleted, many water- or solvent-sensitive components no longer had to be processed separately or soldered by hand.

The development of LSFs for soldering of electronic assembly required several procedural and organizational modifications. Because of the reduced activity of the solder flux, it became necessary to improve soldering practices. This included greater necessity for cleanliness of incoming circuit boards, improved solderability of electronic components, expanded utilization of first-in, first-out inventory control, enhanced storage facility temperature and humidity control, and elimination of potentially harmful packaging materials. Zytec also released a position paper to all of its customers and suppliers asking for their cooperation in obtaining complete elimination of CFCs by 1991.

The implementation of LSFs resulted in improved quality, efficiency, and savings. The complete absence of large pieces of cleaning equipment freed up factory floor space. The number of circuit boards waiting to be processed after soldering was dramatically reduced. The escalating costs of CFCs were completely eliminated. Water treatment and disposal costs were reduced. The turnover of solder in the wave-solder machines was reduced. All these changes added up to improved quality in the manufacturing process, increased efficiency, and a dramatic decrease in health concerns such as skin irritations and allergic reactions.

The Zytec policy of eliminating CFCs was formally introduced in April 1989. The goal was to reduce usage by 50 percent, from over 65,000 pounds in 1988 to less than 32,500 pounds in 1989, and to zero by the end of 1990. This Zytec policy for CFC reduction has received favorable recognition from customers and industry groups. In addition, Zytec reviewed the CFC reduction program in its successful application for the 1991 Minnesota Quality Award and the Malcolm Baldridge National Quality Award.

The John Roberts Company, a commercial printer, was led to reexamine its use of solvents when approached with a problem by its industrial laundry: the company's press wipers contained too much solvent. The John Roberts Company used leased towels to wipe their presses clean. The towels are sent to the industrial laundry for cleaning and with them has done a great deal of ink and spent solvents. When the wipers were cleaned, the solvents were released into the sewer system and caused a problem because of their flammability and toxicity. The laundry asked its major printing customers and their trade association, The Printing Industry of Minnesota, to work out a solution. Faced with this challenge, The John Roberts Company decided to focus on changing the nature of the solvent they were using and on reducing the volume of solvent left in the towels.

The first task was to find a solvent that balanced the production need for speed with the environmental needs of reduced toxicity and volatility. Press operators prefer solvents that flash off quickly and do not require a lot of repetitive wiping or leave behind an oily film. An audit revealed that press operators had been using a highly volatile solvent as a general all-purpose solvent. This product, which is a blend of acetone, toluene, methyl ethyl ketone, and isopropyl alcohol was never intended for cleaning presses, but once used had easily become a habit that was hard to break. Further analysis showed that almost half the total volume of this solvent (nearly 46 percent) evaporated before it could do any work. The replacement solvent, and ultra-fast blanket wash, is easy to use and doesn't leave behind an oily film. The old solvent had a projected usage of 152 55-gallon drums for 1989 and was reduced to just 5 drums in 1990. That same year, only 38 55-gallon drums of the new solvent were purchased. The net savings to the company, even including the purchase of the replacement solvent, amounted to more than $18,000 the first year.

Having reduced the volatility and toxicity of the solvent, the company turned to reducing the total volume of solvents left in the towels. The first step was to make sure that employees were not dumping excess solvent in the pile of used wipers. The company then tested the use of a commercial grade laundry centrifuge. To their surprise, the centrifuge removed a significant amount of solvent from the wipers. Today, before wipers are sent out for cleaning, they are spun in a safe, explosion-proof centrifuge which extracts between 2- to 3-gallons of spent solvent for every load of approximately 220 wipers. The company uses 7,000 wipers a week, which translates into 4,136 to 5,790 gallons of solvent recovered each year. Instead of going out with the wipers to the laundry, this recovered solvent is now reused throughout the plant to clean press ink trays. In 1990, more than 5,100 gallons of spent solvent were prevented from reaching the laundry's effluent. Reuse of this solvent eliminates more than one drum per week of virgin solvent that would otherwise be used to fill parts washers throughout the plant. A welcome bonus of this program has been substantial savings of more than $34,000 in the first year alone. The cost of the centrifuge (about $15,000 installed) was paid back far more quickly than expected. In the second full year of the program, the company has annual savings of more than $50,000.

This project is an excellent example of the application of readily available procedures and equipment. The results are a methodology that is reasonably affordable, very effective, readily adapted, and easily transferred to other industries.

Sheldahl is the largest manufacturer of flexible printed circuity in the United States. Some of these products are so thin and flexible they can be tied into knots and bows and still work. Solvents play a critical role in the manufacture of these circuits. Sheldahl uses solvents to dissolve adhesive resins that are used to laminate materials such as plastic film and copper foil. The adhesive systems are applied to the plastic film and then the solvents are driven off in a drying tunnel. This leaves the film with a tacky adhesive surface which is then combined with copper foil. Solvents are also used to clean Sheldahl's manufacturing equipment.

Sheldahl had been using two solvents, methylene chloride and trichloroethylene, that are suspected carcinogens. In 1988, the company established an objective to reduce solvent emissions from its facility in Northfield, Minnesota. The reduction plan includes water-based adhesive systems, oxidizable adhesive systems and solvent free technologies. To implement the reduction plan, an air emissions reduction team has been formed. Meeting weekly, this large cross-functional team is made up of members of the management team, research and development, manufacturing, purchasing, product engineering, sales, and manufacturing engineering. The CEO of the company participates regularly in these meetings along with other members of the management team.

The results of the program have been the complete elimination of trichloroethylene and a 75 percent reduction in methylene chloride emissions over the last three years. This has been achieved through chemical substitution and process improvements. Methylene chloride has been gradually replaced by less hazardous, non-chlorinated organic solvents. The emissions of these organic solvents (primarily Methyl ethyl ketone, toluene, and acetone) have been further reduced by the use of a catalytic oxidizer to convert them to carbon dioxide and water. Trichloroethylene has been completely eliminated through the use of the solvents listed above.

The company has also reduced solvent use through improvements in facility operations. A solvent use reduction team made up of production operators was formed to reduce the amount of solvents used in the cleanup up equipment and to improve the use of adhesives. The team also identified the need to better match the batch size of adhesives with the amount of product that was being produced. This was done by updating the specification sheets to call out mixing instructions for 40, 30, 20 and 10 gallon batch sizes. This allows the planners, mixers and operators to match the correct amount of adhesive with the roll length of the product. In the past, the standard batch size was mixed and used regardless of the amount of product manufactured.

Sheldahl continues to work with its customers to move toward products that cause less emission. Sheldahl is currently working with more than 100 different customers in executing the plan. The company states that the involvement of many groups has made the pollution prevention efforts at Sheldahl a reality. Sheldahl management recognizes the contributions made by its Air Emissions Reduction Team, employees, the Amalgamated Clothing and Textile Workers union and the residents of the Northfield community. The reductions also could not have been achieved without the cooperation of customers in accelerating testing schedules and participating in the product conversions necessary to eliminate the use of methylene chloride and other chemicals. The community, the company and customers have all created and reaped the benefits of this pollution prevention program.

In 1987, IBM Rochester was the fifth largest emitter of ozone-depleting CFCs in the nation. In 1992, IBM Rochester will achieve zero CFC use in all manufacturing processes. The secret to this reductions the substitution of water-based cleaning systems. Behind the simplicity of this solution, however, lie a number of technological and organizational adaptations.

The computers and hard disk drives manufactured at IBM must be extremely clean. For example, a fingerprint or dandruff flake is a very large defect in a hard disk drive. Thus, precision cleaning is critical to quality products. IBM took a considerable risk in cleaning magnetic disks and piece parts of hard disk drives with water-based systems, In making the conversion to water-based cleaning systems, management directed the CFC elimination team to make no compromises on quality and safety. This directive led to a number of innovations.

The water-based cleaning systems include centralized cleaning facilities, cleaning with deionized water containing a surfactant for removal of contaminants, maintaining rinse water in constant motion, using ultrasonics inside deionized water baths, rinsing of parts in multiple successive tanks with hot deionized water, spraying to rinse parts, and constant filtering of rinse water. Parts are never allowed to dry between process steps. The cleaning process is designed in a countercurrent pattern. This means that deionized water flows from the final rinse towards the beginning of the rinse tanks. Racks that hold parts are designed to orient parts for efficient draining of rinse water. Parts are lifted very slowly from the final hot rinse tank to allow the surface tension of water in contact with parts to draw water back into the rinse bath. Before entering a drying tunnel, an air knife (air forced through a long narrow slit) is used to blow water from parts. Next, parts move slowly through a hot air tunnel to complete drying. Parts exit the tunnel directly into a clean room for product assembly. In most applications, the new aqueous systems clean parts better than the CFCs.

The circuit board manufacturing areas eliminated the use of CFCs for cleaning by changing a resin-based solder flux to a water-soluble solder flux for pinhole soldering and to a solder paste for surface mount boards. The water soluble solder flux can be effectively cleaned using deionized water followed by a drying tunnel.

A small number of complex subassemblies are very difficult to clean and dry, and aqueous cleaning of these parts has not been successful. Ozone-depleting CFCs have been substituted with hydrochlorofluorocarbon solvents (HCFCs). Work is in progress to replace HCFC cleaning during 1992.

IBM's pollution prevention project is an excellent example of the benefits gained by treating environmental problems as an integral part of management for quality and productivity. The CFC elimination team that developed the aqueous cleaning and drying systems worked across several manufacturing processes with engineers from each area. The effort also involved education of employees. Manufacturing employees in centralized aqueous cleaning areas were trained in manufacturing skills integration. Internal awareness education for the CFC elimination project has included a Precision Cleaning without CFCs class attended by 160 employees. A monthly CFC newsletter is distributed to interested employees, and CFC displays were set up in the cafeteria during Earth Week in 1991.

A unique feature of the CFC source reduction project is the outreach activities that have been conducted with IBM suppliers. Suppliers were asked to use non-CFC cleaning processes on production parts supplied for IBM products. Specification requiring the use of CFCs have been revised by the company, and CFC equipment loaned to suppliers has been returned to IBM and new processes have been installed. IBM engineers are working with suppliers to help eliminate CFCs and IBM has developed an educational class to help these suppliers.

IBM Rochester's source reduction of CFCs was a wise decision for the environment and the company's bottom line. Cost of equipment was approximately $7 million. New equipment amortized over several years is already receiving a payback with additional savings in 1992 and beyond. A conservative estimate of the raw material savings achieved over a 7-year period from 1991 to 1997 totals $23.2 million. Subtracting the $7-million investment in new equipment, that comes to a net savings of $16.2 million over 7 years. In addition to a direct chemical saving, IBM Rochester will benefit from processing improvements, centralized cleaning operations, reduced chemical handling, productivity enhancements, reduced cycle time, less maintenance support, improved cleanliness of parts, eliminated Minnesota Pollution Prevention fees for CFCs and reduced cost of supplies as suppliers implement non-CFC cleaning processes.

The annual use of CFCs was reduced from the peak of 935,000 pounds (1988) to less than 30,000 pounds in 1991. Elimination was 100 percent complete in all all manufacturing operation with the scheduled shutdown of the last two small CFC cleaning tanks in December 1991.

This successful project has provided the opportunity for quality and productivity increases. Maintained high level product quality proves that the innovative aqueous cleaning processes implemented at IBM Rochester can be applied throughout the electronic computer industry.

January 1992