News19,126 Articles

October 16, 2003

Eco-friendly CDs

Sanyo turns to corn for a greener optical disc

Martyn Williams

Sanyo has developed an optical disc based on a polymer derived from corn which, it says, is as sturdy as current plastic discs but will biodegrade when disposed of.

The company, which is labelling the technology a world first, will begin selling its MildDisc in December. It is initially targeting volume customers producing prerecorded compact discs such as music CDs, VideoCDs or CD-ROMs, said Ryan Watson, spokesman for Sanyo.

The discs have been designed to tackle a problem common to many plastics upon disposal. If burned, toxic gases can be released into the atmosphere causing health and global warming concerns. But if buried they don't break down, which is a potential problem for future generations.

The MildDisc will degrade after a period of about 50 years to 100 years and break down into water and carbon dioxide, Watson said. This timespan means users don't have to worry about losing information during the lifetime of the discs, he said.

The production process begins when US company Cargill Dow, based in the farming state of Nebraska in the US, converts the corn into a polylactic acid. This is done by milling the corn to separate out the starch and then processing the starch to get unrefined dextrose. Using a fermentation process similar to that of beer production, the dextrose is transformed into lactic acid.

Next the acid is converted into a polymer to form the base of the optical disc by Sanyo in a process the company developed with Japan's Mitsui Chemicals and for which the companies have applied for patents, Watson said.

Sanyo estimates that around 85 corn kernels, each weighing an average of 0.5g, are needed to produce enough polymer for a single 12cm optical disc, so an average ear of corn can produce around 10 discs.

The International Recording Media Association estimates world demand for CDs at around nine billion annually and the US Department of Agriculture calculates world corn production at about 600 million tons, so making enough polymer to satisfy the demand for discs would require less than 0.1 percent of the world's corn production.

Initially the company will focus on discs for prerecorded applications although it is considering recordable and rewritable versions of the MildDisc. DVDs based on the same technology are also a future possibility, according to Watson.

When sales begin at the end of this year, the disc blanks will sell in bulk for roughly three times the price of current plastic discs. However, Sanyo estimates it will be able to reduce this premium to around 1.2 times as much as production ramps up and volume shipments begin.

Cargill Dow is using the same initial process and its own refining process to produce its NatureWorks polymer film. Several companies are using the film to make a range of goods including cartons, candy wrappers, kitchen utensils and acrylic sheets and fabrics

<<newer story | back to index | older story>>

What is this?

Subscribe to PC Advisor now and claim your FREE gift

Keep up to date by adding PC Advisor News to your iGoogle home page or Google Reader


Question of the day!

Does your smartphone replace your need for a laptop when on the move?

Question of the day!

Does your smartphone replace your need for a laptop when on the move?

% of PC Advisor readers agree with you

Yes
TBC
No
TBC

What tasks can your smartphone do that would have traditionally been done on a laptop?

119 characters remaining

Follow the conversation at @SmartphoneFocus

e-mail, tasks, Calendar checks RT @Auldbreck

email and calandar managment via RT @wrighct

email, calendar and, I suppose, document viewing. But you can't really successfully edit documents on a smartphone RT @MattJEgan

Google


Recent reviews

Reviews index


Latest reader comments

Latest reader comments


Top news

News index


Latest blog entries

Blogs index


 Our RSS feeds

Sponsored Content

  • Take the internet to new places with the Nokia N800
    Communicate how you want to, where you want to with instant messaging, email and internet calling. View movies, browse the internet wirelessly and watch TV on the high-resolution screen and listen through high-quality stereo speakers with headphone jack.
    Buy now