ALL ABOUT CORK
What is Cork?
Cork is a material whose applications have been known since Antiquity (Phoenicians and Greeks), mainly as a floating artifact and as a sealant, whose market, since the beginning of the 20th century, has expanded enormously, especially in face of the development of cork agglomerates. Natural cork is the suberous layer of cork oak (Quercus suber L.), constituting the covering of its tree trunk and branches.
Cork has a cellular or alveolar structure. Chemical Composition: The cork consists mainly of Suberine, Lignin, Polysaccharides, Cerides and Tannins.
These characteristics make cork light, elastic, practically impermeable to liquids and gases, an excellent thermal and acoustic insulator and with a high resistance to fire.
Expanded Black Cork
It is only used cork of the branches (falca) for the manufacture of cork granules. These are block clusters in an autoclave, a process that’s 100% natural, without the use of additives. This technology, developed by Sofalca, consists of injecting water vapor through pellets that will expand and agglomerate with the resin of the cork itself. This “cooking” also gives the resulting cork a dark color, like chocolate. During the production of the steam, biomass is used, which is obtained in milling and cleaning the falca, and that’s what makes it a truly ecological production and without waste, with a 95% energy self-sufficiency. This super-material, cork, offers a huge range of advantages, because, in addition to being an excellent thermal and acoustic insulator and as well as antivibration, it’s also a CO2 sink, playing a key role in the environment.
How was it born?
The black cork agglomerate was accidentally discovered in 1891 by the American lifejacket manufacturer John Smith of New York, whose manufacture was patented (patent No. 484345) in October 1892. As it was common in those times, the life jackets were made with canvas vests filled with cork granulate, in tubes or in a cylindrical metal, in order to keep the canvas stretched, until the filling was finished. One night, one of these cylinders was forgotten and filled with granules, and by accident, rolled into a boiler. The next morning, John Smith, the owner, when cleaning the furnace, discovered that the heat had not consumed the cork inside the tube, but rather had turned the granule into a perfectly aggregated dark brown cylindrical mass.
Cork Oak Forest
Cork Oak is an autochthonous tree of the oak family, planted in Southern Europe and from which the cork is extracted. It is due to the cork that the cork oak has been valued since ancient times. The extraction of the cork is not harmful to the tree, since it produces a new layer of “bark” (Súber), which can be withdrawn every 9 years.
Cork Oak is an indigenous forest species that is distributed in the western part of the Mediterranean region, where the Atlantic’s influence is felt, which is essential in terms of climate, to reduce the high thermal amplitudes and the dryness characteristic of the Mediterranean climate.
These characteristics occur in Portugal, so it is in our country that an excellent ecological system exists for the development of cork oak that is distributed throughout the national continental territory, particularly in the central and southern areas of the country.
In the reign of King D. Dinis, measures to protect the cork oak and holm oak were implemented, which prohibit and punish practices already considered harmful at the time: burnings, indiscriminate harvesting of the fruit, abundant harvest of green branchs for cattle feeding and above all undue cuts.
Cork Oak is since the end of 2011 the national tree of Portugal, being protected by legislation due to its socioeconomic interest.
Portugal is the world's largest producer of cork - In only 8% of the national territory, more than 50% of cork worldwide is produced. (Quercus.pt)
Cork is the raw material of an industrial activity, which transforms about 70% of the total production, on a global level, by the cork industry, a situation that makes our country a leader in the sector.
The export of cork products accounts for around 3% of total national exports and is around EUR 900 million per year, making Portugal the largest exporter of cork products.
The management of cork oak forests also generates important income at local and inland regions, allowing employment and rural balance between nature and population.
In addition to the exploitation of cork, the creation of indigenous species producing quality meat and milk, which are the basis of agro-food industries of regional and local importance, beekeeping, the harvesting of mushrooms, the development of cultural activities and tourism related to nature. All these are reasons for the defense of the cork oak forest.
In environmental terms, cork oak forests play important roles in soil conservation, regulation of the hydrological cycle, water quality, oxygen production and consequent carbon sequestration in the atmosphere. In terms of biodiversity, the cork oak forest is a very rich ecosystem that has already been studied in nature conservation at a national and international level.
Only in terms of birdlife, there are over 120 species, some of them with vulnerable or endangered status, such as the Imperial and Bonelli Eagle or the Black Stork. Besides birds, species like the Iberian Lynx, the Boar and Rabbits are also a part of this ecological system.
When using cork in your home, you are protecting the planet, because in addition to being a 100% natural product, you are endorsing the product, instead of other materials that are more harmful to the environment and that do not have the same characteristics on an insulation level. When using the cork agglomerate, you are making a statement, as a human being concerned about the environment and who wishes the best of the best for the insulation of your home or commercial space.
The production of the expanded cork agglomerate uses only superheated water vapor, produced by a steam boiler fueled with the grinding and finishing residues themselves, and no other products other than cork are being used. The agglomeration of the granules is made through the resins of the cork itself, making this product 100% natural and ecological.
The use of cork products is very important from the energy point of view, because in addition to the energy consumed at home, it is using a long-term renewable product, promoting the fixation / stabilization of Carbon Dioxide production.
At the end of the period of use, often imposed by the end of the lifecycle of the building or work, when it is feasible to collect the expanded cork agglomerate boards, these can be reused in identical applications, since material recovered from buildings with over 50 years have shown that, after that time, the appearance and the essential properties of cork agglomerate boards remain unchanged.
In the event that this is not possible, it is possible to grind it by obtaining a regranulate which, like clean regranulates, is destined for new applications in thermal and acoustic insulation or to be used as inert material for the manufacture of light concrete and mortars.