PLASTIC FROM PLANTS
Ballooning Demand for Plastic Made from Vegetable Resin (January 7, 2005)
Plastics made using the resin of corn and other plants are seeing a rapid increase
in demand. As they produce no extra carbon dioxide when burned, these materials are useful in the
fight against global warming, and a technological revolution has made them easier
to use. Polylactide, one of the most well known of this group of plastics, has
been approved for use in food containers, dramatically increasing the number of
applications. Once the price of this plastic comes down to the level of that of
synthetic plastics, its use is likely to become commonplace.
|Products made using vegetable resin (Mitsui Chemicals)
Helping to Prevent Global Warming
Polylactide is a common vegetable resin made from the sugar of such plants as
corn, sugar cane, and sweet potatoes. When plastic made from petroleum is burned,
carbon dioxide is produced, but when plastic made from plant resin combusts, it
only releases carbon that has already been taken from the air in the process of
photosynthesis by the plant. Additionally, when this type of plastic is buried
after use, or put into a composter, it breaks down naturally into water and carbon
dioxide. It can also be recycled.
Up to now, the food-packaging industry has taken a cautious stance on the use
of this plastic, and its applications have been limited to specific parts in automobiles
and household appliances. But as the Japan Hygienic Olefin and Styrene Plastics
Association, an industry association of chemical makers, has now approved the
use of polylactide in food packaging, demand for polylactide plastic appears certain
Exploring the potential uses of polylactide in Japan has been a task mainly undertaken
by major chemical manufacturers, but Toyota Motor Corp., which has been active
in the area of biotechnology, has begun operating a plant in Aichi Prefecture
that is capable of producing 1,000 tons of polylactide annually using sugar cane.
With an eye toward mass production, the company intends to assess the cost and
quality and then produce vegetable resin that will not only be used in automobile
parts but will serve as the supply for a variety of other products. Toyota has
also expressed a desire to get into the business of supplying raw materials. Toyota
Bio Indonesia was established in that country in 2001, and it cultivates sweet
potatoes over an area of 100 hectares. Toyota appears set to raise its production
five-fold in fiscal 2004 (April 2004 to March 2005) to 5,000 tons of polylactide,
with the goal of increasing this figure to 200,000 or 300,000 tons in the future.
Previously, polylactide suffered from being both hard and heat-sensitive. A technological
revolution has been underway the past few years, though, facilitating the blending
of polylactide with other vegetable resins. The company Unitika Ltd. succeeded
in raising the heat-resistance of polylactide from 60 degrees Celsius (140 degrees
Fahrenheit) to 130 degrees Celsius (266 degrees Fahrenheit), making it microwave-safe.
There are expectations that it will be used in the packaging for bento
(boxed lunches) sold at convenience stores. Toray Industries, meanwhile, has developed
a soft film that can be used in a variety of packaging materials.
Smaller companies are getting in on the action as well. One firm has developed
a bento tray and dividers made from tapioca starch
obtained from a plant called cassava. This material can withstand temperatures
ranging from -40 degrees Celsius (-40 degrees Fahrenheit) to 220 degrees Celsius
(428 degrees Fahrenheit) and can also be colored and printed on. Other companies
have made trash bags and supermarket packages, film to keep fruits and fish fresh,
cooking and eating utensils, and even medical instruments from corn.
The biggest obstacle to the mass use of vegetable plastic at present is price.
While mass production has lowered costs, plastics made from vegetable resins still
cost two to three times as much as those made from petroleum. Industry insiders
say that vegetable plastic must be no more than 20% more expensive than petroleum plastic
in order to catch on in a wide range of applications. The domestic market for
plastic is currently about 15 million tons annually, and plastic made from vegetable
resin accounts for only about 10,000 tons. Experts say that a 10% share of the
market is a reasonable interim goal.
People in the industry are touting the fact that polylactide is biodegradable
in that it can be broken down into carbon dioxide and water following use. In
order to bring this point home to consumers, last year such products have been
referred to as "plant based," and makers are looking to sell them to
environmentally conscious consumers and corporations.
Copyright (c) 2005 Web Japan. Edited by Japan Echo Inc. based on domestic Japanese news sources. Articles presented here are offered for reference purposes and do not necessarily represent the policy or views of the Japanese Government.
(January 9, 2004)
(December 16, 2003)