Science Fair Project Encyclopedia
Cork's elasticity combined with its near-impermeability makes it suitable as a material for bottle stoppers, especially for wine bottles. Cork stoppers represent ca. 60% of all cork based production. Cork's low density makes it a suitable material for fishing floats and buoys. Sheets of cork, often the byproduct of more lucrative stopper production, are used to make floor tiles and bulletin boards.
Cork demand has increased due to a larger proportion of wine being sealed with cork rather than being sold in bulk. Since a tree's bark can only be harvested once a decade or so, supply is highly inelastic. Top quality corks are quite expensive, so cheaper brands have switched to lower quality cork, synthetic plastic stoppers, screwcaps, or other closures. These also eliminate cork taint. The synthetic stoppers also do not dry out and shrink so the bottles do not have to be on their sides to prevent the wine from oxidizing. However, on the down side, both synthetic stoppers and screwcaps present a different set of problems such as oxidation and high levels of SO2, giving wines a rotten egg smell.
Recently cork has also been used in rocket technology due to its fire resistance. It can also be used as bricks for the outer wall of a house. (This was seen at the Portugal Pavilion Expo 2000.)
Cork contamination with harmless but foul-smelling trichloroanisole (TCA) was one of the primary causes of cork taint in wine. Cork related trichloroanisole has almost been eradicated by means of new and reliable production methods. As a result, wooden barrels and cellar conditions are the main cause of TCA in wine today.
Note that the cork oak is unrelated to the family of "cork trees", which are not used for cork product:
- Phellodendron amurense - Amur cork tree or Chinese cork tree
- Phellodendron japonicum - Japanese cork tree
- Phellodendron lavallei
- Phellodendron sachalinense
- APCOR, Portuguese Cork Association
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details