Sony Corporation has developed a new form of packaging using biodegradable film as part of its environmental preservation efforts. Since October 20, 2000, all New Neige (5MDW74NE) blank minidisc (MD) 5-packs sold in Japan have been wrapped in the biodegradable material. The film is based on an aliphatic polyester derived from corn starch. While sufficiently durable to protect MDs and other audio media, when disposed of the film is hydrolyzed into water and carbon dioxide molecules by the action of soil enzymes or microbes. Although the current ink binder used in the packaging is not biodegradable, it does not affect the film itself, and it's biodegradable version is under development..
The new film wrap generates only about half the heat of conventional plastics when incinerated and produces no hydrogen chloride, NOx, SOx, or other toxic fumes. The time required to degrade varies with the temperature, moisture, pH, and type and number of microorganisms present in the disposal environment. In soil or water it can take 1 to 3 years, but in a composting unit only 1 to 2 months. The water and carbon dioxide produced during the film's decomposition promote photosynthesis, encouraging plant growth, thus completing the natural resource cycle.
Because biodegradable films cannot be heat-sealed, Sony, in cooperation with a major printing company, first had to develop the technology to deposit a sealant directly on the film. This also involved numerous tests to ensure that the new film was compatible with existing packaging equipment. The New Neige MDs are the first product awarded the "GreenPla" mark certifying that they meet the safety and biodegradability standards of the Biodegradable Plastics Society, an organization established by resin manufacturers, plastic molding producers, and related enterprises to promote environmental preservation.
This is not the first such effort by Sony. The company has previously developed and used environmentally conscious packaging based on recycled paper, with soybean ink printing, and placed half-wrappers on some of its products. Sony will continue to develop products and technologies to lighten the environmental burden from its manufacturing and other activities.