Sony Pioneers Use of Corn Based Plastics

sony_walkman_red-lg.jpgOne of our readers suggested we pay more attention to Sony's growing use of corn-based plastic. Turned out to be a great idea. Here's an overview, with some life cycle analysis thrown in. In early 2003, a Sony webpage was dedicated to promoting and explaining corn-based plastic materials. In early 2004, Sony, in conjunction with Mitsubishi Plastic, announced that they had developed a new engineering polymer from corn-based polylactide. The corn polymer was said to be as strong as ABS (acrylonitrile butadiene styrene). This was the breakthrough material needed for housings. Importantly, Sony used inorganic flame retardants instead of brominated retardants such as PBDE's (polybrominated diphenylethers), as such substances will be prohibited under the EU's RoHS Directive from July, 2006, forward. In the 2004 announcement, Sony mentioned they planned to use the new material for the manufacture of front panels for electronic goods, the Walkman's in particular. Much more below:From cultivation to disposal, the corn based plastic was said to emit 20% less of the greenhouse gas per volume than conventional petroleum-based plastics. We have to assume they did some life cycle inventory studies to back this up.

Although critics have pointed to the use of genetically modified corn in the PLA feedstock, as always, TreeHuggers should be mindful of the tradeoffs. Step one, make it practical. Step two, seek life cycle perfection. Examples abound. Take Tantalum for example. Some of this rare inert metal's ore comes from Africa. Google the topic and you'll see allegations of what Tantalum ore (coltan) mining means to conservation, social stability, and human rights there. The analogy is direct and simple. Peviously you could not own a handheld electronics device of any kind that does not rely on tantalum for capacitor functionality. Alternatives are under development, but until then you won't be canceling your cell subscription right? There's more. Got some body piecings? You could even be wearing it. Been to see a surgeon? Those surgery tools are likely made from it. Tradeoffs. OK now: back to our story.

Less than two years following Sony's lead, corn based polymer has captured the attention of designers in several industries. Versace, taken by corn plastic's ability to mimic wool, cotton or silk, has begun weaving apparel out of NatureWorks' Ingeo fibers. Smaller fashion designers have accepted Ingeo as well. Families are now eating Del Monte fruits and vegetables from corn plastic containers, drinking Biota water from corn plastic bottles and soda at McDonald's out of corn cups. Fujitsu Ltd. in a tie-up with Toray Industries Inc. has developed nonflammable, vegetable and petroleum-based plastics for its laptop personal computers. NEC Corp. said that a new technology, jointly developed with Unitica Ltd., blends the vegetable plastic with kenaf fiber to increase the material's heat resistance.

Overall sales of the PLA based plastic were reported up 60% last year. ALthough still more expensive than tradtiional engineered plastics, we can surmise that the continued upward march of oil and natural gas, both important feedstocks for petro-plastics, will put PLA plastic in a more favorable light. Combining this trend with the European and Japanese regulations that are slowly pushing toxic heavy metals like lead and cadmium out of the electronics design palatte, TreeHugger thinks that the Cradle-to-Cradle (C2C) ideal has a hope for success in the electronics field.

Tags: Chemicals | Conservation | Pollution


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