Page 149 - Design for Environment A Guide to Sustainable Product Development

128 Cha pte r Ei g h t

mixed plastics. One of the key differences between virgin and recy-
cled resins is color tolerances, which may be important if two parts
are immediately adjacent. Producing all mating parts from the same
lot of raw materials can minimize variability in physical and aesthetic
attributes.
Example: Mohawk Industries, a carpet manufacturer, converts over 3 billion
bottles annually—25% of all the bottles collected in North America—into 160
million pounds of recycled carpet fiber. In addition, Mohawk recycles about 10
million pounds per year of crumb rubber from about 720,000 scrap tires into
designer door mats. Finally, Mohawk has replaced cardboard carpet cores with
those made from recycled carpet edge trim, plastic bottle tops, and stretch films.
These new cores last longer, are less likely to damage the carpet, and can be
recycled into new cores.

Renewable Material Specification
Instead of recycling nonrenewable materials, an alternative approach
is substitution of renewable materials such as agricultural products.
Materials are considered renewable if the rate at which they are
replenished is sufficient to compensate for their depletion. For exam-
ple, as discussed in Chapter 12, many automakers are beginning to
use natural materials derived from crops such as flax or soybeans
for car interiors (see Figure 8.4). Other examples of products that use
renewable materials include soy inks and wooden furniture.

Remanufactured or Refurbished Components
Durable products can be manufactured with refurbished compo-
nents, resulting in lower costs and reduced material consumption,

FIGURE 8.4 Many recent Ford models, such as the pictured Mustang, use
soy-based foam for seatbacks and cushions.