CorkArt Cork Floors

corkArt cork flooring

CORKART is a private, family owned company founded by Joseacute Correia Neves in 1997, although he has been involved in the business for more than 20 years. All operations are headquartered in Vendas Novas, Portugal, a town located in the heart of the Portuguese cork oak forests, approx 1 hour south of Lisbon.

With a covered area of 15,000 square meters, CORKART employs more than 100 people. State-of-the-art manufacturing equipment, excellent design and highly trained, skilled and experienced workers are just a few of the benefits of dealing with CORKART. CORKART produces high quality products: Cork Floor Tiles, Cork Floating Tiles, Cork paper, Cork Textile and Cork articles, using a unique product, CORK. Last couple of years CORKART also developed new product lines like Lino Concept Collection and Vinyl Concept Collection, creating once again design, stylish and quality floating floors that are perfect for any environment.

CorkArt Concept Collection rapidly became the most important production sector. Thanks to our exclusive designs, best water based finishing and UNICLIC profile. CORKART does not produce any waste related with cork. Everything is used including cork dust which helps heating our machines.

brochure corkArt cork flooring

Info - Quick Fact of Cork
Cork is the outer bark of the evergreen cork oak (Quercus suber). This variety of oak grows mainly in Portugal, Spain, southern France, Italy, and the Maghreb.

Cork consists of a tight web of up to 40 million cells per cubic centimeter. The cell membranes retain gas, giving cork its capacity to float, insulate and re-expand quickly after compression.

Cork is natural, recyclable and biodegradable. No natural or man-made material replicates its properties.

Cork is sustainable. It is harvested by stripping the bark every nine years. Each cork oak tree provides an average 16 harvests over its 150-200 year lifespan.

Cork retains unique qualities of flexibility, elasticity and compressibility. Its extreme resilience, impermeability, lightness and insulating efficiency make it ideal for a large number of applications.
Info - Cork Chemical Composition
cork cellCork cells are a minute, straight-sided pentagonal or hexagonal prism. The cell height rarely exceeds 0.045 millimeters but decreases to 0.02 to 0.01 millimeters in the last cork bark formed in the autumn. Following the invention of the optical microscope in the 1660s, the British scientist Robert Hooke was the first to observe the structure of cork, for which he coined the term 'cell'. 50% of cork is gas enclosed in the cells. Suberose sacs make the cork cell membrane impermeable and the cell airtight. Suberin, a mixture of fatty acids and heavy organic alcohols, is the basic substance of cork. Impermeable to gas or liquid, it is also fire and insect resistant and unaffected by water.

The average chemical composition of cork is:

· Suberin (45%) - the main component of the cell walls; responsible for the resilience of the cork

· Lignin (27%) - the binding compound

· Polysaccharides (12%) - components of the cell walls which help define the texture of the cork

· Tannins (6%) - polyphenolic compounds responsible for color

· Ceroids (5%) - hydrophobic compounds that ensure the imperviousness of cork

· Mineral water, glycerine, and others make up the remaining 4%.
Info - The Process of Harvesting Cork
The harvesting of cork consists of stripping the outer bark of cork oaks. The best time for bark stripping is at the most active phase of the cork oak's annual growth: from May or June to August.

Cork is harvested in steady cycles that promote healthy growth of the tree over its life span of 150 to 200 years. Each cork oak provides an average of 16 bark strippings.

The first stripping of the cork bark takes place once the tree trunk reaches a circumference of 70 centimeters and stands 120 centimeters tall. However, the cork will only be fit for cork stoppers from the third harvest onwards. So it often takes over 30 years before wine-quality cork can be harvested.

The first harvest produces cork of a very irregular structure. This is called 'virgin cork'. Nine years later, the second harvest brings 'reproduction cork' - a material with a more regular structure, less hard, but still not suitable for cork stoppers. 'Reproduction cork' is usually granulated for use in products such as flooring.
It is from the third and subsequent harvests that the cork with the best properties is obtained - the 'amadia cork' - and from this time, the tree will provide good quality cork for about 150 years.

The stripping, when done by professional loggers, does not harm the tree, because the first layer of reproduction cork merges with the continuously developing virgin layer in the unstripped part of the tree.

The stripped area, known as the 'mother', changes from a rose color to red ochre, then a reddish brown, and the following year to a gray, crust-like formation. Loggers use a special axe for the harvest. The blade is used to make the incision while the end of the handle is shaped to detach the cork.

cork - stripping bark cork - stripping by loggersFigures: The harvesting of cork consists of stripping the outer bark of cork oaks. And the stripping of cork oaks is done by professional loggers.

To keep the trees in good health, government laws regulate the harvesting of cork oaks. In Portugal, trees are harvested in cycles of not less than nine years. Calendar years are painted on the bark to monitor when a tree was last stripped.

The delicate operation of stripping cork has been performed in the same way for decades. Today, cork stripping with a special axe continues to be the quickest and cleanest method available.

The stripping process consists of five steps:
- Opening
- Separating
- Dividing
- Extracting
- Removing

The first operation is opening, where the cork is slashed vertically, choosing the deepest crack in the cork bark. At the same time, the edge of the axe is twisted so as to separate the outer from the inner bark. At this stage it is possible to gauge the degree of difficulty of extraction from the 'feel' of the axe. When the edge of the axe is applied to the strip, a hollow sound of tearing is heard if the cork is going to come off easily. If it is going to be difficult, the axe gives off a short, firm, dry sound.

The plank is then prised off the tree, by inserting the edge of the axe between the strip and the inner bark. The axe is twisted between the trunk and the cork in order to peel off the cork in large panels from the main sections of the trunk.

After a horizontal cut, a dividing line is drawn between the cork plank to be removed and what is to remain on the tree. The plank is then removed from the tree with care so that it does not split. The larger the planks extracted, the greater their commercial value. The removal of entire planks depends on the skill of the workers. After the first plank has been stripped, the operation is repeated over the whole trunk.

After being harvested, the cork planks must stabilize. They are sorted according to their future use as natural cork stoppers, discs, or agglomerated cork products, depending on their quality.

The selected planks are then stacked in piles to be exposed to sun, wind and rain for six months or more. During this period, the elements purge most of the sap from the cork, the polyphenols are oxidized and the cork texture stabilizes.

cork - boilingFigure: Boiling cork planks

After stabilization, the cork planks are boiled in clean water for at least one hour. All cork must be boiled before it is worked to make it more pliable, and to fully expand the lenticels.

The cork cells are collapsed and wrinkled before boiling, but after boiling, the gas in the cells expands and creates a very tight, more uniform cell structure. This hot water process makes the cork increase its volume by about 20 per cent, and become flatter and smoother.

The boiling operation - a standard procedure defined by the International Code of Cork Stopper Manufacturing Practice - also ensures that microflora is significantly reduced. But many manufacturers are using complementary procedures to achieve significant improvements. Some have introduced computer controlled boiling, processed in a closed environment. The cork industry is striving for even better cleaning methods.

Once the boiling is finished, the cork planks are dried and left to rest in warehouses with controlled humidity and temperature for three weeks. Cutters then trim the edges to make the planks rectangular.

The trimmed cork planks are sorted into various thickness and qualities, depending on the porosity and certain structural defects that the cork may have.

After the three-week resting period in the warehouse, the trimmed planks are sliced into strips and cork stoppers are punched out.

Regular cork strips are ideal for automated punching; less regular strips may be processed by manual punching.

cork - drilling machine Figure: Automated cork stopper drilling machine. (notice the cork waste produced in the cork stopper production – We will use this type of waste to produce cork floor)

After punching, the ends of each raw cork stopper are cut to size and polished.

Suitable leftover cork pieces are processed into agglomerated corks. Agglomerated cork stoppers - made from compressed cork granules - receive the same care and attention to detail as solid corks.

Unused cork and even cork dust is processed into other cork products such as insulation and construction materials. Nothing from the cork tree is wasted.

Cork stoppers are biodegradable and recyclable. Many local cork recycling initiatives help to conserve this natural resource. Although the recycled cork is never used again for wine stoppers, it has many other uses - such as for the manufacture of memo boards, place mats, coasters, floor tiles and gaskets.
Finally, corks are automatically counted, sanitized with sulphur dioxide gas and sealed in gas-barrier bags.