What Makes Cork One of Nature’s Most Extraordinary Materials

Can we start by you giving us the background to Amorim?

Amorim was founded in 1870. It’s a family business – our chairman is from the family’s fourth generation. The company’s founder was Antonio Alves de Amorim. He started a very small manual cork stopper factory in Villa Nova de Gaia, in the city of Porto, north Portugal, and slowly the factory was extended, and then new factories were founded, and we became leaders in the industry. In the 1960s, our then-chairman, a third-generation Amorim, changed how we worked – rather than just produce cork stoppers, we began to use leftover material from the stopper production process and created another company, Amorim Cork Composites,which focusses on developing high-performance composite cork materials for other industries. Now our materials are used in various business sectors. At least ten. We are, right now, the world’s biggest cork processing group.

You still produce stoppers?

That’s Amorim’s main business.

I read somewhere that if you buy a bottle of wine, the bottle’s cork stopper is most likely to have been produced by Amorim…

Well, yes – we produce over five billion cork stoppers per year.

How is the cork produced?

It’s important to say that Amorim doesn’t own cork oak tree forests. We buy our cork – cork is the outer bark of the cork oak tree – from trusted suppliers around the world. Portugal is one of the world’s biggest suppliers of cork. But you can also find it in Spain, Morocco, Italy, across the Mediterranean basin. It is one of nature’s most extraordinary products: natural, reusable and recyclable, light, flexible, practically impermeable to liquids and gasses, an excellent thermal, acoustic and vibration insulator. When the bark is stripped, it doesn’t damage the tree – over time, normally a period of nine years, the bark regenerates. When a tree is planted, we must wait 43 years to harvest it. It takes 25 years for the tree to become mature enough for it to be stripped for the first time, when the trunk has reached a diameter of 70 centimetres. But the cork then is not of good enough quality to be used. The bark regenerates and is stripped again nine years later, but still it’s not of high enough quality. So we must wait for the third regeneration cycle. Then it is boiled, and it is put through other processes, and then it is ready to use. The average life expectancy of a tree is about 200 years. It is very, very sustainable. And it has many different properties, which are helpful in the contexts of a wide range of applications: it’s an insulator, it is soft to touch, it’s resilient. Cork has a honeycomb structure, like a foam. Often we compete with synthetic foam manufacturers, but cork is a natural material that can be reused and recycled.

Cork is a competitor to synthetic foam?

It depends on the sector. In some cases we compete with foam manufacturers. In others it’s rubber. Usually we compete with alternative products; we don’t compete with other cork manufacturers.

Tell me more about sustainability.

Sustainability is important to us. Since we’re leaders in the industry we work hard to guarantee the maintenance of cork oak forests, and to protect them against deforestation. These forests are remarkable ecosystems – they prevent soil degradation, they generate high levels of biodiversity, they regulate the hydrological cycle. The farmers we work with are very well paid – they are the experts – and we only use FSC accredited cork. And cork is excellent for the climate. Cork oak forests sequester carbon. When you produce a product using cork, for example, there is a high retention of CO2. For every one ton of cork produced, it’s estimated that we can sequester up to 73 tons of CO2.

The forests are a carbon sink…

Exactly. That’s why it’s so important to maintain them.

What sectors are you working in?

Aerospace, mobility, energy, the power industry, footwear, design, home goods, construction, flooring, sports… As a material it seems to have infinite potential. People always seem surprised that since the 1960s we’ve supplied cork to be used in the aerospace industry, to be used on launchers and rockets. As I said, cork acts like a foam – it can protect materials from very high temperatures, and it protects from over-heating. It is also flexible, it is resilient, it has a high resistance to friction, it is a natural shock absorber. Often we provide components to aerospace firms and they supply those components to organisations like NASA. In some cases the material requirements are so technical that we formulate materials to the specific needs of aerospace clients.

You have a presence worldwide?

Yes. Amorim Cork Composites alone supplies to 500 companies in 80 companies. And innovation is part of our DNA. We study how we might create cork materials to be used in new applications and products, how we might use new processes: grinding, lamination, compounding, molding and shaping. It depends on the specific needs of an industry or an application. When we develop new products, we consider how we are consuming raw materials, the energy that might be consumed in its production, the release of pollution into the natural environment of…

The idea that the bark of a cork oak tree – this natural material – could be part of a rocket that launches into space seems remarkable…

It is. It’s a natural material, but it offers very high technical performance. It’s light. It insulates. We worked on another interesting project recently with the energy company EDP. We were asked to develop a sustainable floating platform – a floater – made out of cork composite, that would support 11,000 photovoltaic panels floating in the Alqueva reservoir in Portugal. EDP was originally going to use a plastic-only compound. By using a cork composite, the company reduced at least 30% of the solar park’s CO2 footprint. And there are so many other uses: railway infrastructure, children’s playgrounds, football pitches. On wind turbines, for example, cork is used on the blades to ensure they don’t ice over, because cork is light and a natural insulator. The same is true in the automobile industry and in trains – cork is used as flooring, again because it is light, and durable. You can use cork as a structural material, as in the mobility and aerospace industries. But it looks good, too, so you can use it as a visual material also. Mazda has used cork in the interior of their 100% electric MX-30 car. It enhances a feeling comfort – as well as being environmentally friendly, it is naturally beautiful.