In the material selection, designers should aim towards choosing as much abundant, non-toxic, non-regulated materials as possible. If toxic materials are required for the manufacturing process, then they need to be generated on-site, rather than having them shipped elsewhere. If possible, natural materials should be chosen over synthetic materials. Most of the needed materials should be coming from the recycling streams rather than through the raw material selection. Minimum use of materials in products, processes, and services should be the general rule in design. Composites that are in common use include reinforced plastics with glass or carbon fibers. That way, a composite has the best properties of each material. Carbon fibers are strong and heat-resistant, but also expensive to use. Glass is cheaper and relatively easy to manufacture, but there are many disadvantages. Glass fibers present a health risk to those working with them. Fiberglass is non-degradable, difficult to recycle and cannot be incinerated because the fibers are left behind in the clinker and can damage the furnace. A better way to reinforce the plastics is the use of natural fibers. Daimler Benz uses them in its vehicles since 1995.
Recycled plastics should be used whenever possible. They are particularly suitable for applications without strict performance criteria like strength, flexibility, and color. Often, their use is for products such as drainage pipes, marker posts, flowerpots, bins and crates. Design strategies for plastics include specified use of plastics that have less impact on environment, lightweighting, and use of recyclable plastics whenever possible.
CLEAN CHOICE
There are three main sources of waste: industrial, post-consumer industrial waste, and post-consumer domestic waste. Industrial waste, like manufacturing scrap, which is collected and reused in-house, can be relatively clean and uncontaminated. Post-consumer waste, like industrial products that have been used and discarded, is more difficult to recycle because of the presence of contaminants such as dirt, food, paper labels, and others like plastics.
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