Sony Designs Vegetable-Based Plastic

Sony Corporation, as part of its efforts to contribute to environmental conservation, 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 as its first product to feature vegetable-based plastic.

The vegetable-based plastic Sony plans to use for the housing is polylactic acid, 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 percent of the casing in terms of its total weight. While conventional plastics are pro-duced from petrochemicals, the vege-table-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. Material recycling of the plastic is also technically possible. The vegetable-based plastic can be used as a packaging material by thermoforming transparent sheets. Sony introduced the plastic in the packaging of compact radios this year.