Quercus suber L.: cork you say?

    By Cindy Couture

    Cindy Couture visited Portugal as part of a special architecture + design journalists tour created by Esther Shipman of Culture Viewfinder and sponsored by Tourism Portugal

    Line of cork furniture named Sobreiro of the Campana brothers. Source: Armorim

    Visiting Portugal last autumn, FORMES magazine had the chance to visit the headquarters of Amorim, a multinational cork processing company founded in 1870. This hundred-year-old company, which is famous in several markets, with the big names in design and architecture to demonstrate all the characteristics of this raw material. A brief overview of the properties of cork and its possible applications.

    An Ecological Material

    This substance, commonly known as cork, is actually the bark of the cork oak, Quercus suber L. The cork is made from 100% natural plant tissue and is composed mainly of suberin and lignin. It is necessary to wait twenty-five years before being able to make a first harvest. After that, it will be possible to harvest every nine years. To harvest, the bark is removed from the tree, so that no trees are cut during this process. The tree regenerates simply and continues to grow. The extraction, always carried out between May and August, is carried out when the tree is in a more active phase of its growth. Among all types of trees, it seems that cork is the only one whose bark is self-regulating.

    The first idea that obviously comes to mind when we talk about cork is the wine bottle stopper. However, it is necessary to wait for the third harvest (forty-three years) even before being able to create corks with the quality required to do it. The first two extractions, virgin cork and secondary cork, will be able to create insulating materials, floor coverings and various products in the field of construction, fashion, design and products for the aerospace industry.

    At Amorim, we get cork from hundreds of landowners, whether in Portugal or in other countries such as Spain, Algeria, Morocco, Tunisia and France. Agreements between the company and the landowners enable it to harvest on time and provide additional income for these owners. It is only recently that Amorim has announced the acquisition of its first cork forest estate.

    Portuguese designer Filipe Alarcão offers an ice bucket made of agglomerated cork.

    Inspiring Features ...

    Cork has many interesting features. The story reveals various projects where it has inspired great architects and designers. Indeed, Amorim has created significant collaborations to demonstrate the unique properties of this material. Whether through the participation in the construction of various emblematic buildings or the development of a range of objects and accessories called MATERIA, the creative possibilities of cork have been highlighted many times.

    Of Great Lightness

    Since more than 50% of its volume is air, cork is a very light material. This is what gave the architect João Luís Carrilho da Graça the idea of combining cork with concrete in order to reduce the weight of the structure of the new Lisbon cruise terminal, built in 2018. Portuguese architect has mixed with natural white concrete a natural cork granulate, to create a facade 40% lighter than with traditional concrete.

    The architect João Luís Carrilho da Graça combines cork with concrete to reduce the weight of the structure of the new Lisbon cruise terminal. Source: Armorim

    In addition to being beautiful, the cork / concrete mix adds a subtle texture to the surface, which is accentuated under the glare of the sun. The result combines the thermal insulation of cork with the durability of concrete, in addition to meeting the requirements of the maximum loads related to the existing foundations of the place.

    With a weight of 0.16 grams per cubic centimeter, cork is a material that floats without any problem. Inspired by this feature, Atelier Big-Game proposed the Bote for the MATERIA collection. Composed of a cork shell and a plastic accessory (a sail, a row of engine chimneys or a cabin), Bote is the ideal toy for an imaginative navigation to entertain children during the daily bath.

    Bote, toy consisting of a cork shell and a plastic accessory (sail, fireplaces or cabin).

    Thermal and sound insulation

    Cork has a low thermal, sound and vibration conductivity. Indeed, the gaseous elements that it contains are enclosed in small impermeable properties and isolated from each other. From the collection of MATERIA objects, the Portuguese designer Filipe Alarc ã o proposed an ice bucket in agglomerated cork. This ice bucket with a lining lined with a plastic case takes advantage of the thermal insulation properties of cork associated with its unique texture. It keeps the temperature low inside, while the outer surface retains its natural warmth and provides a pleasant and soothing sensation.

    Raincoat

    Thanks to the suberin and the steroids present in cell walls, cork is impermeable to liquids and gases. Its resistance to moisture allows it to age without deteriorating. Thus in 2012, Herzog & de Meuron made it the raw material of their ephemeral flag made for the Serpentine Gallery in London. The team of architects created a circular pavilion under the threshold of the earth. The pavilion was buried five feet underground so as to reach the water table. The interior of the pavilion was almost entirely covered with cork. The architects described cork as a natural material with great haptic and olfactory qualities and a versatility that allowed it to be carved, cut and shaped. Thus, thanks to cork, they wanted to simulate the characteristics of the excavated soil. The pavilion attracted more than 750,000 visitors.

    Ephemeral cork pavilion made for the Serpentine Gallery in London by Herzog & de Meuron. Source: Armorim

    Fireproof and pressure resistant

    Cork is a natural flame retardant: it does not burn and does not release toxic gases during combustion. In addition, it is a solid that retains its volume when it is under pressure in a certain place. Its elastic memory allows it to adapt to changes in temperature and pressure. As architect João Luís Carrilho da Graça says after his experiments: "You can leave a piece of cork under a weight for centuries and when you remove the stone, the cork gradually returns to its original shape, which is really surprising. There is no natural material that does that, and I do not know artificial material either. I think that cork is extraordinary! "

    During their presence at Experimenta Portugal in 2018, the Campana brothers presented a first line of cork furniture named Sobreiro. Composed of an armchair and three cabinets, the collection combines the beauty and versatility of cork. The armchair is made entirely of natural cork blocks reminiscent of the traditional wine stopper while the cupboards are made with different types of cork: an expanded chipboard, an expanded chipboard composite and a mixture of cork and clay. The material thus exploited allowed the famous designers to design a solid, curvilinear and light design.

    Hypoallergenic

    Finally, this material is thought of as a hypoallergenic substance. As it does not absorb dust, it protects against allergies. This may have prompted Nendo to use this material for everyday objects such as a PAR salt and pepper shaker and a two-part fruit bowl, PARTE. In the latter, the two halves of the bowl can be connected in different ways, which allows users to change its proportions and use as they please.

    A hypoallergenic substance, Nendo uses cork for everyday objects such as salt and pepper shakers or fruit bowls.

    In short, although these are only a few of the applications and collaborations between Amorim and the world of design, the fact remains that cork is surprisingly flexible and versatile. The Portuguese company is also pursuing several research and innovation projects in the field of aerospace. Closer to home, we can think of cork flooring or the sub-floor more and more used as insulation. Thus, it is a world of possibilities that opens in terms of creation. Obviously, we are at latitudes of simple use as a wine stopper. And you, how would you use this raw material?