• Cork is the phellem layer of bark tissue that is harvested for commercial use primarily from Quercus suber (the cork oak), which is native to southwest Europe and northwest Africa. • Because of its impermeable, buoyant, elastic, and fire retardant properties, it is used in a variety of products, the most common of which is wine stoppers. • Cork is 100 percent natural, sustainable, reusable and recyclable.
Cork is a natural material used by humanity for over 5000 years. Cork presents a characteristic cellular structure in which the cells have usually a pentagonal or hexagonal shape. The cells of cork are filled with a gas mixture similar to the air, making them behave as authentic “pads,” which contributes to the capability of cork recover after compressed. The montado landscape of Portugal produces approximately half of cork harvested annually worldwide, with Corticeira Amorim being the leading company in the industry.
Cork production is generally considered sustainable because the cork tree is not cut down to obtain cork; only the bark is stripped to harvest the cork. The tree continues to live and grow. Over the course of its lifetime, which on average lasts 200 years, it may be stripped around 17 times. The sustainability of production and the easy recycling of cork products and by-products are two of its most distinctive aspects. Cork oak forests also prevent desertification.
Cork has low conductivity to noise and vibration and is a good thermal insulator because the gaseous components are enclosed in semi impermeable compartments, isolated from each other by a moisture-resistant substance. It is also naturally fire resistant, burns without a flame and does not emit toxic gases during combustion. Over 50% of its volume is filled with air making it extremely light at just 0.16 gm per cubic centimeter and it can float. It doesn’t absorb dust, is thus hypoallergenic and safe for asthma sufferers.
It is moisture resistant and is practically impermeable to liquids and gases. It is extremely resistant to abrasion and has a high friction coefficient.
Most of the cork, around 70%, is used as bottle stoppers; however, this material is also largely used for the production of cork-based composites employed for different technological applications, such as for the building industry. The good damping properties of cork make it appropriate for load-bearing applications, acting as filler in other plastics and elastomers formulations. Used in civil construction as insulating material, it is also applied as thermal and anti-vibration shields in spacecrafts, both by ESA and NASA. Cork is an excellent gasket material. Some carburetor float bowl gaskets are made of cork, for example. Cork is also an essential element in the production of badminton shuttlecocks. Sheets of cork, also often the by-product of stopper production, are used to make bulletin boards as well as floor and wall tiles. Cork's low density makes it a suitable material for fishing floats and buoys, as well as handles for fishing rods (as an alternative to neoprene).