(excerpt from an article in January/Febuary 2002 Green@Work magazine)
by William McDonough and Michael Braungart

For nearly a decade we have been working closely with forward-thinking companies to lay the foundation for an era of ecologically intelligent design. As the desire to develop sustaining enterprises grows, we thought it would be instructive to examine the breakthroughs and innovations that are revolutionizing product design; they offer lessons, insights and practices that can inform a wider movement towards a life-centered commerce that creates economic, social and ecological value.

Nylon 6 is an ideal material for use as a technical nutrient and the key to the transformation of the carpet industry. It is first of all highly stable, and carpet yarn made from nylon 6 is easily depolymerized into its precursor, caprolactam. The heat used in the process can be largely recovered, and caprolactam, in turn, can be re-polymerized and made again into nylon 6. In contrast, nylon 6,6, a popular carpet material, is made of two constituent elements-trying to separate and re-use them, says BASF's Ian Wolstenholme, is like "trying to unbake a cake." Best efforts downcycle nylon 6,6 carpet fiber into low-performance applications like carpet backing.

Nylon 6 was first developed in the 1930s, yet only in the past decade has a company, BASF, seen its value as a material that can be retrieved and reused in closed loop cycles. In 1996, BASF initiated its "6ix Again" nylon recycling program and the company is currently following our eco-effective strategy as it works to design a carpet yarn and develop systems for its reclamation that would make nylon 6 a pure technical nutrient.

BASF SAVANT™—Upcycling Carpet Fiber

In the 1990s, BASF developed a carpet material called Savant™, made from nylon 6 fiber. Carpet yarn is typically pre-dyed, but through a combination of polymer and fiber engineering, Savant™ can be dyed in custom colors at the last possible moment to reflect fashion and customer taste, yet it has properties that make it inherently stain resistant and inherently colorfast.

Those properties make Savant a competitive, high-quality product. What is even more interesting to us is its potential as a technical nutrient. Because it is made of nylon 6, Savant can be depolymerized and used again and again, which is just what BASF has begun to do. BASF uses recycled content from its carpet take back program, 6ix Again, transforming old nylon 6 carpet into Savant. Rather than being downcycled into a material with less value, the used nylon is what we call upcycled into a product of higher quality, closing the technical cycle with a flourish. The nylon is rematerialized (not dematerialized), the essence of Cradle to Cradle Design.

Full of Promise

For all its promise, Savant is not yet a pure technical nutrient. Working with MBDC, our design chemistry firm, BASF will now begin to actively select and develop pigments and additives that, like nylon 6, can be used again and again. The systematic approach of eco-effective design extends to the development of the systems and logistics for the reclamation of technical materials. 6ix Again is a good start. Ultimately, following an eco-effective agenda, the company could perhaps become a nylon bank, leasing nylon as a product of service for defined use periods within a system that guarantees the reclamation and reuse of the material in a closed-loop technical cycle.

Along with its high chemical stability, the low toxicity of its building blocks, and the ease with which it can be upcycled, nylon 6 is an exceedingly versatile material. As a plastic it is strong and durable; as a fiber it is flexible and resilient. It performs equally well as the housing for electronic equipment, automobile windshields or outdoor gear. Indeed, every element of a lightweight tent could be made of nylon 6, from poles, to zippers, to mesh windows. Designed within a reclamation system that rewarded the return of the tent's valuable materials, it would be a completely recyclable technical nutrient, quite in keeping with the outdoor ethic of many hikers and campers.

As it has been said, if it exists, it is possible. We have reached a point in the development of the design arts and sciences in which all the tools for ecologically intelligent design have been assembled. The materials exist, the technology exists, the knowledge and creativity exist. The story of nylon 6 is just one of many that illustrate how the merging of all of those elements can yield effective, beneficial, high-quality products.

A world of intelligent design and sustaining prosperity is not only possible it has begun to take shape in products already in the marketplace. Someday soon you just might find one of them right underfoot.

An Invitation

The possible applications of nylon 6 are many. In fact, we'd like to invite the design community to come up with a host of new, innovative products made of nylon 6 and designed as technical nutrients. BASF's Bob Armstrong, a former research and development manager currently a representative for quality and environmental issues, will help you find knowledgeable sources on performance data for nylon 6 as well as information on the availability of the material. (He can be reached at 704-423-2376.) The MBDC team is available to provide technical consulting on the systems and logistics of designing material recovery systems. We hope this invitation sparks the emergence of a whole spectrum of products that help create an enduring market for high-quality technical nutrients.

Previous Monthly Features:

May 2001, "The Five Steps to Reinventing the World" (Step 1: Free of...)

June 2001, "Positive Design Decisions in an Imperfect Market" (Step 2: Personal Preference)

July 2001, "Textile Mills Lead Another Revolution"

August 2001, "Synthetic Materials for Eco-Effective Design"

September 2001, "Transforming Product Design within Current Production Systems" (Step 3: The Passive Positive List)

October 2001, "Do you know what they want to do now?" by Tim O'Brien, Director, Ford Environmental Quality Office

November 2001, "The Breakthrough to True Eco-Effectiveness" (Step 4: The Active Positive List)

December 2001, "Just Doing It. Nike's Track to Ecologically Intelligent Products" by Darcy Winslow, Nike Director of Women's Footwear

January 2002, "A Footprint Worth Celebrating" (Step 5: Reinvention)