Cork
Cork is a vegetal material that comes from the bark (súber) of oak trees (Quercus suber) and has a high insulation power. It comes essentially from Portugal, where there are about 720 thousand hectares of Oak trees, as well as from the Mediterranean regions like Spain, Italy, France, Morocco and Algeria. However, the most important economic impact of the cork industry is concentrated in Portugal.
The oak tree can live from 150 up to 200 years and it has an enormous regeneration capacity. Throughout its existence cork is harvested more or less16 times (every 9 years).
Only after a period of 25 years of existence can the first cork be harvested. This cork is called virgin cork. Nine years later cork is again harvested, being thus called “secundeira”. This process can only be done every 9 years. The third time cork is harvested (that is, at the end of 40 – 50 years) it is finally possible to have the best cork to produce stoppers (this sort being called “amadia”).
As it is a natural product, unique and with unparalleled qualities, it is considered a noble raw material which can have a wide range of uses, for example, seal in bottles of wine, in floor coatings, in insulation (thermal and acoustic), in footwear and components for the car industry…
Cork main features:
1. very light
2. Impervious to liquids and gases
3. Elastic and compressible
4. An excellent thermal and acoustic insulator
5. Burns very slowly
6. very resistant to friction
Privilege of nature
Balance of a poor ecosystem, obliged to creat self-defenses:
>> Isolation, lightness: 50% of the volume of each cell consists of air;
>> Impermeability: A natural waxy-Suberina makes it impermeable to liquids and gases;
>> Fire retardant: Natural qualities don't allow the spread of flames and in combustion doesn't realease toxic gases;
>> Resistance, elasticity: When subjected to pressure or friction the compressed gases soon recover their original form after decompression;
>> Durability: Even subjected to great pressures the cork doesn't die; like diamonds, cork is ... FOREVER.
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