Sony to launch Walkman with casing made from vegetable-based plastic Vegetable-based plastic to be used for over 90% of casing's total weight

June 12, 2002

Sony Corporation announced today that, as part of its efforts to contribute to environmental conservation, it has developed a technology to use vegetable-based plastic for the casings of electronic devices. Sony plans to use the new material in a Walkman model to be launched this autumn as its first product to feature vegetable-based plastic.
The vegetable-based plastic Sony plans to use for the housing is polylactic acid, (*1) which is made by fermenting corn. Conventional polylactic acid lacks the physical properties required for it to be used for durable consumer goods such as electronic equipment. Sony, however, has been developing a method to improve polylactic acid's physical properties, working with Mitsubishi Plastic, Inc. and Sanpo Kasei K.K. These efforts have succeeded in giving the material sufficient durability, heat and shock resistance, and moldability for it to be used for the casings of electronic products. Sony plans to use this new type of vegetable-based plastic in more than 90% of the casing in terms of its total weight.
While conventional plastics are produced from petrochemicals, the vegetable-based plastic is made from plants, which are renewable resources and thus can contribute to saving finite resources. When disposed of, the vegetable-based plastic decomposes completely to carbon dioxide, water, and inorganic substances through a catabolism process induced by microorganisms or enzymes in composters. (*2) Material recycling of the plastic is also technically possible.
The vegetable-based plastic can be used as a packaging material by thermoforming transparent sheets, and Sony plans to introduce the plastic in the packaging of compact radios in August.
Sony has been introducing environmentally considerate materials in its products, such as lead-free solder and halogen-free printed wiring boards. Sony will continue to develop technologies that contribute to minimizing the environmental impact of its products and manufacturing processes.

  • *1Polylactic acid is made by fermenting corn starch or sugar using lactic acid bacteria and then chemically polymerizing the ingredients. It is biodegradable and gradually decomposes to water and carbon dioxide in the environment.
  • *2Composters are machines that produce compost from organic waste such as fallen leaves and kitchen refuse. They provide an environment of high temperature and humidity that is suitable for microorganisms and accelerates the natural decomposition of decaying plants.
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