Materials Choices: Material Differences

Tomorrow’s appliance and automotive components are on the drawing boards today. The materials coming into recycling yards right now were designed 15 years ago and most likely manufactured five to 10 years ago.

While these companies are most interested in selling product today, they are aware that even the best-built appliance or vehicle has an end-of-life to worry about. In Europe, cradle-to-grave custodianship of goods is becoming commonplace. Although there is resistance to the idea in North America, many observers believe that manufacturers eventually will be held responsible for disposal of goods they produce.

However, while designing large consumer products today to make it easy for recyclers to handle their products tomorrow is important, it is the consumer who drives design. There is an apparent division between auto and appliance manufacturers when it comes to how aggressively end-of-life design is incorporated into products. Appliance firms seem more concerned about handling individual materials like insulation and freons than with overall product disposal.

"I don’t see a significant change in the mix of materials," says Mike Campbell, vice president of research and development for Maytag Appliances, Cleveland, Tenn., www.maytag.com. He says that currently about 75 percent of the materials in appliances are readily recyclable materials like steel and aluminum. 

"Recently, we’ve seen increased popularity among consumers for stainless steel kitchen appliances, and we may see more extensive use of electronic controls in some appliances in the future. But overall, I don’t see a radical change in the mix of materials," Campbell says.

According to Washington-based Association of Home Appliance Manufacturers (www.aham.org), the average length of appliance ownership varies from a low of 6.8 years for garbage disposals to a high of 11.2 years for freezers.

AHAM finds that, in almost every appliance category, the average age of units has increased since 1990. This indicates that appliances are being replaced or left behind less often than in the past. The average age of trash compactors has increased from seven to 11 years and may indicate that units owned are being replaced very infrequently.

In categories that include both gas and electric appliances, an AHAM study found the two types have similar lengths of ownership.

The Appliance Recycling Information Center (ARIC), associated with AHAM, says "white goods" have long useful lives, typically 10 to 18 years. Discarded appliances are second to only automobiles as a source of recycled metals, particularly steel. However, shredders also recover aluminum and copper and must deal with plastics and other materials.

Unlike with vehicles, weight is a minor consideration. "We are not intentionally trying to make our appliances lighter," Campbell says. "During the design process we take the overall weight of the product into consideration, but that is done because of product installation issues, not recovery issues."

This past March, General Motors Corp. (GM), Detroit, was the first automaker to put its vehicle recycling information manuals on its Web site. The dismantling manuals give End-of-Life Vehicle (ELV) information.

The manuals provide automotive dismantlers—both auto salvage companies and shredder operators—with information on which parts of a vehicle can be recycled. New manuals provide details about how to dismantle for recycling the 2002 models of the Cadillac CTS and Seville, Chevrolet 1500 van, S-10 truck, Tahoe, TrailBlazer and Camaro. Other manuals available online include 2000 and 2001 models of the Oldsmobile Alero, Cadillac Seville, Chevrolet Camaro, Chevrolet Corvette and the entire family of light-duty trucks with the exception of the Chevrolet Astro.

GM also notes its own role in using recyclable materials. Up to 200,000 pounds of Saturn fender scrap are recycled into wheel cap assemblies. More than 2,750 tons of recycled fabrics from the textile industry are used for floor insulation per model year. GM makes radiator side air baffles from 56,000 recycled tires per model year. Together, GM Canada, Mexico and U.S. facilities recycled or reused 23 percent of all hazardous and 74 percent of all non-hazardous solid wastes generated at its plants, the company estimates.

Meanwhile, GM is changing vehicle components, although more for manufacturing efficiency than recyclability. GM says it will use aluminum sheet for the hoods of the next models in its Hummer all-terrain-vehicle line, the H3s, due out in 2005. According to a report in American Metal Market (AMM), the H3s will be the first models in the Hummer line equipped with aluminum hoods. AMM says GM seriously considered specifying plastic composites for the hoods of the new vehicles, but settled on aluminum because it would be able to fabricate the components itself and realize cost savings if the H3s sell in high volumes. Aluminum also beat out steel in the competition for the new hood applications, primarily as a result of weight-saving benefits.

The plastic hoods on the Hummer H1 and 2003 H2 models are bought from outside suppliers.

Across their product line, Chrysler engineers figure 75 percent by weight of a typical car or light truck is made up of metal. At the end of their useful lives, most vehicles are destroyed. Most of the steel and aluminum in ELVs is returned to the manufacturing process. Metal recycling companies around the world are busily recycling steel and other metals back to the manufacturers. But typically, up to 25 percent of a car becomes auto shredder residue (ASR) and is often landfilled. This 25 percent is the focus of a demonstration project at the Chrysler Group, Auburn Hills, Mich.

"We’re concentrating on recovering plastics from the shredder residue in the CARE Car II program," says Gerald Winslow, Care Car Program Manager for Chrysler. "The CARE Car II program has the potential to reduce the amount of material going to a landfill and put it back into new automobiles." DaimlerChrysler estimates the process eventually will help increase vehicle recyclability from 75 percent to 95 percent by weight.

The CARE (Concepts for Advanced Recycling and Environmental) Car project involves a proprietary flotation technique that automatically separates, extracts and dries different types of plastic residue from ELVs at a current rate of up to 1,500 pounds of residue per hour. The recovered plastic is melted and formed into plastic pellets that are then mixed with virgin plastic to create the new vehicle parts. As an added bonus, the machines extract not only plastic but also foams and residual metals.

The CARE Car II program worked with 27 suppliers, retrofitting two Jeep Grand Cherokees models with 54 recycled plastic parts. In this second stage of the CARE Car program, the Chrysler Group used the automated materials separation system to more effectively recycle three of the most widely used plastics in automobiles - ABS (acrylonitrile butadiene styrene) resin, polyurethane foam and polypropylene.

"We recognized at the start that if we were to dismantle these plastic parts from ELVs by hand, that would push up the cost of the dismantling process substantially. Also, the pile of polypropylene parts taken from a vehicle would contain other materials. Ultimately, hand dismantling would cost more than using virgin materials in the manufacturing process," Winslow says.

The program’s focus now is to make the bottom line the driver for the use of recycled materials. "We want to make it financially worthwhile for our parts suppliers to use recycled plastic," adds Bernard Robertson, Chrysler senior vice president of engineering technologies and regulatory affairs.

"Whether it’s altruism or economical, recycling is something we have to make work," he says. "And with landfill costs going up, recycling costs are eventually going to come down."

By using its proprietary automated technology, the company figures it can cut the cost of the recycled plastic to as much as 30 percent below that of virgin plastic. In fact, the process is so cost-effective that DaimlerChrysler estimates this process could conservatively save the automotive industry roughly $320 million per year. Group supply partners played many different parts in the demonstration project.

One company developed headlamp mounting modules made from recycled plastic gloves and bottles, reducing materials costs by 15 percent. One plastic moldings supplier developed a recycled-content version of its body flaring/skirting. Another helped develop and test the fender liners.

Ford’s global stamping, casting and forging operations annually use more than 2 million tons of recycled metals. The company’s German plants recycle 94 percent of what would have been waste materials and lost energy. A waste minimization and recycling strategy increased the recycling rate at the sites almost 20 percent in three years.

In the auto arena, plastics continue to make inroads at the expense of metals. Mazda Motor Corp., Tokyo, has developed a new polypropylene plastic as the structural material in modular carriers for the assembly of modular parts, and has also developed a new injection molding technique for glass-fiber reinforced polypropylene that realizes greater strength.

Thus, integration of functions by the combination of parts, largely difficult to do with previous modules, has improved together with the possibility of substantially reduced cost and vehicle weight.

Few, if any, U.S. appliance manufacturers seem to have formal programs aimed at end-of-life recovery. "However, we’re very interested in the subject, and we have general design guidelines that call for us to consider end-of-life recovery issues when we are designing new products," Campbell says.

The European-style cradle-to-grave programs may push a change in appliance design parameters. "Eventually, I think we’ll see a trend in that direction, but the scope and details of any such programs remains to be seen," Campbell says.