All about cork
Green Collect began back in 2002 just collecting cork. Lets find out a little
bit more about the valuable resource that it is...
Cork really does grow on trees, specifically as the bark of the cork oak (Quercus
The largest cork forest in the world is in Portugal with Spain, Morocco and Algeria also boasting huge plantations. France and Italy have very small forests and the US, Australia and Japan have experimented with planting.
Around 13 billion corks are produced each year with the biggest company Amorim, based in Portugal, producing approximately 3 billion corks.
Harvesting cork is 100% environmentally friendly, leaving the forest and its wildlife intact. The bark is harvested from the cork oak in a cyclical fashion that helps promote the healthy growth of the tree. Virgin cork won’t be removed from a tree until its 25th year and the ‘reproduction’ cork (all further cycles) is only harvested every 9-12 years.
In fact currently the greatest threat to the cork forests is the advent of cork alternatives such as screw tops for bottles and artificial corks both of which can be environmental hazards.
Why is cork so useful?
Cork has a unique cell structure in which each cell is filled with an air like substance, sealed and not internally connected to any adjacent cells. A strong resinous substance bonds each cell together. This unique natural design gives cork some very useful properties including:
- Resiliance. Cork is very useful because it can be compressed by exerting pressure, yet return to its original volume when the pressure is removed, making it perfect for creating a seal in bottles. Of course too much pressure will result in the cells collapsing.
- A high friction surface. When you cut cork, thousands of little cups are created which create a vacuum when pressed against a smooth surface.
- Imperviousness to water and other liquids, including oil.
- Vibration and sound absorbency. When hit with sound or vibration the air filled cells compress soaking up the energy that is being transmitted through them.
Low density and low thermal conductivity. The unique air filled cells are also poor energy transmitters. Uses for cork
- Bottle stoppers/ closures/ corks
Cork’s compression ability, impermeability and high friction surface make it ideal for sealing bottles or containers holding liquid.
The insulation and low energy transmission properties of cork make it an excellent flooring material. Commercial applications include anti-slip flooring for wet areas and in work places where the natural ‘give’ reduces strain on workers standing for long periods of time.
The automotive industry use cork to form seals between two metal surfaces.
- Visual Aides
Cork can be used for bulletin boards, or as underlay for chalk boards or white boards.
- Building and engineering products
Dams and breakwalls use cork for joints using its self expanding qualities. Some buildings use cork for it’s sound deadening properties and NASA has even used cork as protective insulation during re entry from space.
- Sporting Goods
Cork is used in sports like fishing (floats, handles and grips), baseball and cricket (bats and balls).
- Speciality products
Cork is used for planters, coasters, decorative purposes, musical instruments and event to assist with environmental issues such as oil spills.