Designing for disassembly: Auto recycling requires planning from initial design phase

NASA Tech Briefs, Jan 2003

Environmental protection through recycling is something every American has become familiar with we recycle large amounts of trash at home, we recycle at work, and we're encouraged to purchase products made of recycled materials. What you may not know is that, according to the United States Council for Automotive Research (USCAR), the automobile is the most recycled product on Earth.

USCAR - the umbrella organization of Ford, General Motors, and DaimlerChrysler - states that about 75 to 85 percent of the content of vehicles by weight is recycled, and about 95 percent of the cars on the road end up being recycled. By comparison, only 61 percent of aluminum cans, 30 percent of paper products, and 20 percent of glass products are recycled in the U.S.

Formed in 1992, USCAR has a Vehicle Recycling Partnership (VRP) that identifies and pursues opportunities for research in recycling, re-use, and disposal of motor vehicles and their components. The partnership opened a Vehicle Recycling Development Center (VRDC) in Michigan in 1994, which dismantles up to 500 vehicles each year to study ways to recycle materials using cost-effective processes. Each of the "Big Three" automakers in USCAR also has developed its own recycling standards, as well as assessments for end-of-life vehicles (ELVs) - cars that have reached the end of their operating life.

Initiatives in Europe and Japan will require that within 12 years, 95 percent of a vehicle, by weight, be recoverable. In the U.S., such requirements don't exist, and very few regulations are in place that apply to the recycling of ELVs. Any U.S. automaker that exports cars to these regions, however, must meet those requirements. The regulations that do exist in the U.S. focus on waste management, particularly in reference to disposing of vehicle fluids such as brake fluid, oil, and transmission fluid, and scrap tires.

With a greater focus on environmental responsibility, it is becoming more important for automakers to consider recyclability in all stages of a car's lifecycle, beginning at the initial design phase. Engineers are required to take into account all of the ecological and economic considerations of designing a recyclable vehicle.

Today, when automotive engineers design a car, they must consider body style, mechanical systems, manufacturability, quality, and cost, and also the recyclability of materials and components such as fasteners. In addition, engineers must look not only at how assemblies can be put together, but how they can be easily dismantled.

Design for Recycling

Most US automakers have had designfor-recyclability measures in place for a number of years. These procedures cover every aspect of an automobile's design, from conception through design, material selection, assembly, manufacturing, and disposal. Design for recyclability has been a major focus of USCAR's VRP, which has established preferred practices for designing recyclable vehicles.

U.S. automakers are instructed to:

Use recyclable materials;

Use materials that have recycled content;

Limit the number of different materials used within assemblies;

Eliminate the use of substances that are potentially hazardous or cannot be recycled;

Select fastener systems that facilitate disassembly; and

Reduce the number and types of fasteners used.

USCAR also has preferred practices specifically for automotive design engineers that involve the initial design for recyclability:

Reduce the number of parts within an assembly;

Design assemblies so they may be easily removed for reuse or recycling;

Design parts and tooling that optimize material usage; and

Design parts and assemblies to minimize the need for packaging, and select packaging that is reusable, has recycled content, or is recyclable.

With current recommended practices in the U.S. - and the government regulations that exist in Europe and Japan automotive design engineers are facing the growing responsibility of not just designing a reliable, stylish car or truck, but they also must work with environmental and recycling specialists on how the vehicle will be disposed of from the very beginning of the design phase.

Basically, engineers must consider all steps of a car's lifecycle from the initial conception of the design. As a result, most automakers have developed their own proprietary dismantling/recycling analysis software that designers and engineers can use to guide them in how a design can be optimized for recycling.

BMW Group, for example, has developed software that allows virtual dismantling analysis during a vehicle's development phase, enabling the design's suitability for recycling to be determined as early as possible. The dismantling analysis can cover more than 600 disassembled components or groups of components, and in most cases, there are more than 15 individual items of information recorded for each component.

The dismantling analysis also is important as a tool for engineers to use before production of the vehicle begins. BMW completely disassembles each vehicle in order to obtain detailed information on the weight of each component, the materials, the dismantling times required, the tools used, and other data that provides information on the extent and cost of dismantling a vehicle.