Before answering this question, please let me tell you first what is cork fabric. In a short,
Cork fabric is a natural textile made from plant fibers. It is made from a strong layer of specific plant material, oak bark. The phellem layer of bark tissue is used to make cork, a versatile and impermeable material.
Cork fabrics are textiles made from plant fibers harvested from oak trees. The cork fabric then adheres to a textile backing, which is usually backed with other natural fibers such as cotton, linen and flax. The most sustainable backing fabrics are organic and made from cotton, linen or hemp. This sustainable resource is fantastic in terms of functionality and energy efficiency.
Cork fabric is a natural textile that is widely used in high fashion. It is very soft, comfortable, lightweight, long-lasting and durable. It is a material that can be found in many everyday garments, bags and accessories, making it a more responsible choice.
Cork fabrics for sewing can be easily dyed, cut and sewn into a variety of styles and patterns. They come in many types of cork fabrics in a variety of sheens and colors.
That’s why cork is an eco-friendly fiber that is perfect for sustainable fabrics and fashion textiles. It is a natural, durable, 100% biodegradable, compostable and recyclable material.
Cork products benefit the natural and human environment in many ways. They help generate income for artisans and weavers in local communities.
So maybe you will be curious about what is cork?
So what is cork?
As mentioned of cork, the first impression in most people in the world is the cork stoppers in red wine. Because cork has great features that can be widely used as a stopper: impermeable and moisture-resistant, compressible and antimicrobial. But do you know why cork has those features? And what is real cork?
Cork is mainly made from the bark of the cork oak (Quercus Suber) which is grown in sunny and warm countries like Spain, Portugal, Italy, France, Algeria, Morocco and Tunisia. Globally speaking, Portugal is the biggest producer of cork. If you’ve ever traveled to the rural areas of Southern Portugal — where most of the world’s cork oak trees are grown, you will see how cork tree was planted and harvested.
Generally speaking, newly planted cork oak trees take, on average, more than 25 years of growth before their bark can first be harvested. Cork oaks can live up to 250 years and produce between 50 and 100 kg cork in each harvest. Very old and large cork oaks can even yield between 500 and 1300 kg in just one harvest. What is rarely known by most people is that the tree can generate back per eight or nine years. Once the barks protective layer has been peeled, it will regrow silently until it has become plump and thick next time.This fabulous oak is the only tree that will not be damaged by removing the bark. Instead, it is a respected growth period so that the cork gets the nutrients it needs, peeling off the bark is actually good for the Quercus Suber as it means it can absorb three times as much CO2 than an “unpeeled” tree. Just like the kids, we need to have some patience to wait for them to grow up. The plant, in itself, is a miracle.
From cork harvest to cork fabric manufacturing-a long process
The first peeling is also known as “virgin bark”. Virgin bark is rough, uneven, and rich in resin, which is why it is usually used for cork insulation panels or granulation. Peeling the cork bark of the tree is done manually with special cutting axes; it needs to be done carefully in order to avoid damaging the “mother layer”. Both the trunk and the main branches are de-barked; this occurs during the warm summer months when the bark is easier to remove.
After the peeling process, the harvested bark is sorted and stacked in storage areas in the cork oak forests/plantations or close to the cork factories. It is dried in the open air for at least 6 months to guarantee excellent air circulation. After the drying process, the bark is steamed on stainless steel panels to straighten the naturally rounded shape.
This process takes another 6 – 9 months.
As an anti-bacterial treatment, the cork is then boiled. This increases the elasticity and volume of the material and decreases its density. The boiling water is used as a natural fertilizer. After cooling down and drying for a second time, the cork needs to stabilize for about two weeks to decrease the humidity to a degree that makes further processing possible.
Then all the cork raw material was trimmed to be regular shape like this and stored pallet together.
The cork material will be divided into various levels of quality and can be then taken to production sites, for instance, to make cork fabric to cork wallpaper. Only materials of quality levels A and B are suitable for cork fabric and wallpaper production; level C cork is used for granule flooring and insulation. Cork harvest and production are subject to stringent government controls and detailed requirements by the European Cork Association, which must be adhered to. Some thick enough cork sheet material was used to do a wine stopper, which is punched out of the bark.
We usually buy the material by containers, each level quality in a different container, packed like this.
As you can see in below picture, our bread vein cork leather fabric was made by high-quality grade A raw material, which have fewer bugs and stain:
The slub pattern cork fabric in grade B with bigger bugs:
Grade C has bigger bugs, color not so clean:
Grade D have obvious bugs and stains, color was darker:
The leftover material, or post-industrial waste, is boiled and ground up, then compressed using adhesive resins. Our resin is food-grade quality, eco-friendly.
The last process is to adhere the thin cork sheets to a fabric support backing. We have many different backing bases, including cotton, polyester, or poly-cotton, depending on where did you use it.
Why cork fabric?
Cork fabric has exceptional characteristics, which make it perfect to do bags, wallets, upholstery wallpaper, and flooring.
One of the characteristics of cork fabric is its stain resistance. Unlike other materials, cork easily removes stains that may be picked up throughout use. A quick wash with water and soap is all that is required.
The water resistance of cork is one of the best properties of this material and plays an important role in how it has become such a durable fabric. Cork has a waxy substance called corkiness covering its cells, and it is this substance that helps repel water, thus extending the life of the product.
Hold a wine cork and you’ll know it’s very light. Cork weighs only 0.16 g/cm3. Over 50% of the components of the cork are a mixture of gases almost identical to air, making it light enough to float on water.
The honeycomb structure of cork also allows it to resist scratches that may be caused by friction, impact or abrasion. This is another reason why cork is used as an industrial material.
Flexibility and Compressibility
The air-like mixture of gases in the confined cells gives cork its elasticity and compressibility.
The cork retains its elasticity even when compressed to half its volume, and once decompressed
Once decompressed, it immediately regains its original shape.
Thermal and acoustic insulation
Cork contains nearly 40 million cells per cubic centimeter, which effectively absorbs noise, making cork an excellent sound and vibration insulator.
Cork is an excellent acoustic and vibration-resistant material. The molecular structure of cork allows it to absorb and store heat for long periods of time.
time to store heat.
Flame and fire resistant
Cork is not easily combustible and is a natural fire retardant and fire barrier. Cork burns without flame and does not release toxic gases.
Anti-static and anti-allergic
Cork does not attract dust and prevents the breeding of mites, thus helping to prevent allergies.
So, we can summarize cork fabrics as:
- No waste is generated during extraction, processing or production
- No additives, tanning or finishing substances are used to process raw cork into cork leather
- Fully recyclable; can be milled into new materials
- Beneficial to soil and air quality in and around cork forests
- Cork forests sequester 14.7 tons of CO2 per hectare
- Creates homes for thousands of rare/endangered plants and animals
- Grows in Mediterranean countries, mainly Portugal
- Workers love their work; no risk to the health and safety of workers or community members
Doesn’t this harmless, non-polluting, natural and sustainable cork fabric appeal to you? Contact HZCORK today for more details on cork fabrics that can help you boost your business!