Page 36 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

General Introduction

One of the basic principles of design for recycling is the use of materials
and product-design features that facilitate biological or industrial recycling. In the U.S.
automotive industry, for example, about 75% of automotive parts (mostly metal) are
now recycled, and there are continuing plans to recycle the rest as Well, including plas-
tics, glass, rubber, and foam. About 100 million of the 300 million discarded automo-
bile tires are reused in various Ways.

Cradle-to-cradle Production. A term coined in the 1970s and also called CZC,
cradle-to-cradle production considers the impact of each stage of a product’s life
cycle, from the time natural resources are mined and processed into raw materials,
through each stage of manufacturing products, their use and, finally, recycling.
Certification procedures for companies are now being developed for cradle-to-cradle
production, as they have been for quality control (Section 36.6). Cradle-to-grave pro-
duction, also called womb-to-tomb production, has a similar approach, but does not
necessarily consider or take on the responsibility of recycling.
Cradle-to-cradle production especially emphasizes

I. Sustainable and efficient manufacturing activities, using clean technologies.
2. Waste-free production.
3. Using recyclable and nonhazardous materials.
4. Reducing energy consumption.
5. Using renewable energy, such as wind and solar energy.
6. Maintaining ecosystems by minimizing the environmental impact of all activities.
7. Using materials and energy sources that are locally available, so as to reduce
energy use associated with their transport, Which, by and large, has an inher-
ently high carbon footprint.
8. Continuously exploring the reuse and recycling of materials, thus perpetually
trying to recirculate materials; also included is investigating the composting of
materials Whenever appropriate or necessary, instead of dumping them into
landfills.

Guidelines for Green Design and Manufacturing. In reviewing the various activi-
ties described thus far, note that there are overarching relationships among the basic
concepts of DFMA, DFD, DFE, and DPR. These relationships can be summarized as
guidelines, now rapidly being accepted worldwide:

I. Reduce waste of materials, by refining product design, reducing the amount of
materials used in products, and selecting manufacturing processes that mini-
mize scrap (such as forming instead of machining).
2. Reduce the use of hazardous materials in products and processes.
3. Investigate manufacturing technologies that produce environmentally friendly
and safe products and by-products.
4. Make improvements in methods of recycling, Waste treatment, and reuse of
materials.
5. Minimize energy use, and Whenever possible, encourage the use of renewable
sources of energy.
6. Encourage recycling by using materials that are a part of either industrial or
biological cycling, but not both in the same product assembly. Ensure proper
handling and disposal of all waste in the case of materials used that are not
part of an industrial or biological cycle.