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Green design

March 29, 2005

A public radio commentary

Last month I travelled through the Pacific Northwest and California. At every stop I heard about Seattle's new tough recycling laws. Toss too much junk mail and cardboard in the trash instead of the recycle bin, and you'll be fined. Seattle makes mandatory the recycling of everything that can be recycled.

From an engineer's viewpoint, this doesn't make environmental sense. Now, before those nasty emails and letters start arriving, let me emphasize: I said it made no sense to recycle everything that can be recycled, I certainly didn't say all recycling made no sense.

Partly these laws arise because of a commonly held view that we toss, say, plastic soda bottles into the recycle bin and they go back to the manufacturer and they produce another bottle. In other words, a vision of a self-sustaining cycle of life. But the economy of recycling materials is more complex then this.

For example, only a bit of a recycled plastic bottle ends up in a bottle again. Instead it appears in carpets: Half of all polyester carpets come from plastic soda bottles. And there are other issues that determine the use of recycled materials. The cost of picking them up - it typically costs double that of regular trash. Greater costs means additional trucks, fuel and sorting facilities -- all of which take an environmental toll.

This critique, though, has the same flaw as the Seattle recycling laws: Its what an engineer calls an "end of the pipe strategy." In other words, only years after making something do we consider how to dispose of it. Instead we need to focus on "green design" - on designing consumer product from the get go to be reused or disposed. Here's an example. The two-liter soda bottle has a plastic label, which is different than the body of the bottle. So, to recycle this the two different types of plastic must be separated. In the past recyclers separated them with a simple flotation technique: The plastic in the bottle sinks, the labels floated. Recently the manufacturers put a wrench in the works: They changed the type of plastic used in the label to one that also sinks.

So, here are some simple rules for manufactures to incorporate green design, that is recycling their products: Make make the components easily separate so no dissimilar material remain together; make sure common tools like hammers, screw drivers, and pliers will suffice to get it apart; design it so one person can disassemble it in 30 seconds or less; and lastly, be sure each material type can be identified through markings.

So, to be an environmentally friendly we want products designed so that the high value materials can be removed - reserving recycling for metals, using the plastic and wood products for energy-producing incineration, and then - and I know that this will bring in the letters - landfilling the rest.

Copyright 2005 William S. Hammack Enterprises