Jerry Work asked: Cork is a wondrous material that provides mankind with numerous benefits. Cork is made from the bark of the evergreen species of oak genus called the Quercus. The wood is native to southwest Europe and northwest Africa. It has also been introduced into warmer areas of the United States, but by far the number one producer of cork oak is Portugal, which accounts for half of the world’s cork.
The cork oak tree has a very thick bark (known as “cork”), which can be harvested for the first time from the tree after about twenty five years. The cork pulled from the tree is light, flexible, and compressible. It is also resistant to liquids and gases. Its resistance to materials passing through its cells is a result of its chemical composition, which contains a large amount of suberin. Suberin contains acids which make it elastic and compressible. After its initial harvesting, a cork oak tree can be harvested about once a decade.
Cork’s number one use is for wine stoppers. The demand for cork continues to rise as wine makers continue to use natural cork more than alternatives. Natural cork has the advantage of not soaking up the flavor of wines, as non-natural corks can do.
Cork has many other uses beyond its traditional role in capping wine bottles. Due to its fire resistance, cork has been used in rocket technology, as well as to make bricks for homes. Technological innovation has also resulted in the material becoming popular for use in footwear, furniture, and floor tiles.
The waste produced from cork that is heated to extreme temperatures is called black agglomerate. Black agglomerate has many uses as well, such as for vibration, thermal, and acoustic insulators. It is also prized for its appearance and is often used for ornamental and artistic purposes. The grinding of cork produces white agglomerate, which is useful for industrial purposes. White agglomerate is also used in the construction of sporting goods, such as golf clubs, rackets, helmets, and baseballs. Also, cork grains can be combined with rubber to form rubbercork, which is used for electrical and automobile purposes.
As mentioned above, Portugal produces half of the total cork in the world. The country’s pleasant Mediterranean climate is ideal for growing cork oak trees. About 720 thousand hectares in Portugal are devoted to the growing of cork oak trees. One hectare equals 10 thousand square meters, so this represents a very large amount of land. A cork oak tree can live up to 200 years and will typically be harvested many times in its lifetime.
Cork is a natural product that is harvested naturally, so no damage is done to the environment. In addition, the material can be re-used and is biodegradable. There is no synthetic version of cork (the production of which would likely be much more damaging to the environment than natural cork harvesting), so it is a valuable material that does no damage in its production or consumption.
So now you know more about cork than you probably ever though you would. It’s a product with many uses that can be re-generated naturally over and over. It’s truly a wonder wood.
Keith
