Why Cork? The properties of this material in the push for circularity and sustainability
Sep 5 2023
Under Lamp's #WorkitudeForLife label, which promotes projects with a positive impact on the environment and promotes a more sustainable industry, we began a process of 'rematerialization' of our catalog to offer lighting solutions more in line with the circular economy.
An example of this fruitful line of action is the Stormbell 80 Ø363x60 CK bell accessory, produced with recycled cork. In this way, Lamp takes advantage of the properties of cork; a tremendously valuable material that is not only recyclable and 100% natural, but also helps take care of nature.
Cork properties: carbon negative and 100% reusable
Natural cork is obtained from the bark of the cork oak, which grows mainly in the Mediterranean basin, especially in Portugal and Spain, and is a key forestry asset for these semi-arid areas.
What sets the cork oak and its bark apart is its great capacity for regeneration, as when the bark is removed from the trunk it grows back without damaging the tree in the process. To obtain the cork, there's no need to cut down the tree. You simply remove the bark every 9-10 years, which gives it enough time to re-grow. The tree has a lifespan of approximately 200 years, which means the bark can be extracted several times throughout its life.
This de-barking process is carried out manually, using precision tools to ensure the tree isn't damaged. The bark is then left to dry in the open air in order to lose its moisture, and then boiled to eliminate impurities and gain volume and elasticity. The whole process leaves hardly any detrimental environmental impact.
According to the ICSURO (Institut Català del Suro), the main properties of cork include the following:
- Extremely lightweight due to the low density of the cells, 90% of which are made up of air;
- Impermeability to liquids and gases thanks to the suberin (a wax-like fatty substance in its cell walls);
- Thermal insulation: thanks to its low thermal transmittance;
- Acoustic insulation: the porosity of the material allows it to absorb more than 60% of the sound waves that hit its surface;
- High friction coefficient, which means it has a high resistance to movement.
- Elasticity, flexibility, and compressibility. Its composition makes it a very malleable material that can be compressed without losing any elasticity;
- The previous quality results in a high cushioning capacity;
- Stability, rigidity, and durability;
- Hygroscopic, which means it can absorb ambient humidity;
- 100% biodegradable, recyclable and renewable. ICSURO recommends cork as a clear example of circular economy, as it enables a sustainable balance between human actions and agroforestry management.
Cork is regarded as a carbon negative material, as it eliminates more CO₂ than it generates. The cork oak is one of the trees that absorbs the most CO₂ when it carries out photosynthesis. For every kilo of cork, 50 kg of CO₂ are absorbed and removed from the atmosphere.
The main difference compared to other trees is that debarking boosts its CO₂ absorption capacity by between three and five times, as it needs this CO₂ to convert it into energy for bark regeneration.
Design, functionality, and efficiency in the Stormbell 80 luminaires featuring recycled cork
As part of the company's commitment to sustainability, which relies on innovation as a transformative tool, we constantly evaluate the impact of different materials with a view to "rematerialising our catalogue in terms of circularity and minimal environmental impact". The aim here, according to Marketing Director Raquel Quevedo, is to "improve product functionality and design quality".
For this reason, we launched a collaborative relationship with OiKo Design Office, a consultancy firm that combines design and research in the transition towards a circular economy, and, together with them, evaluated the incorporation of circular and/or renewable materials during the design process of our Stormbell 80 luminaire.
Designed by Artec Studio, the Stormbell 80 is a miniaturized version of its predecessor, the suspended downlights in the Stormbell family, and is specifically designed to address the lighting requirements of the new workspaces, which demand architectural solutions with a user friendly design - in order to make us feel at home in the office. The luminaire has four hood typologies of different shapes and sizes, which create different sensations of light and lighting proximity in the layout of the workspaces.
During the design process, three materials were evaluated for the manufacture of the luminaire's hoods: Compact recycled PET (r-PET); Natural fibres (Plant Based); Recycled cork (r-cork)
The rPET and rCork options were the ones chosen to be manufactured in the end, offering a lighting solution that retains the technical lighting requirements (lighting quality, lighting comfort and glare control), while also providing excellent environmental performance and a better user experience, at the same time offering new textures and lighting qualities in line with the user-friendly approach sought with the Stormbell 80.
Stormbell 80 Ø363x60 CK takes advantage of cork's natural properties, which are maintained in the recycled material. This Stormbell 80 is made of 95% recycled cork and 5% PUR resin. It weighs 226 grams and is only 8 mm thick; around 40 wine and champagne corks were used in its manufacture.
The recycled cork used in Stormbell 80 shades comes from recycling stoppers that have been collected by people with social integration difficulties. In turn, the material of the hoods of the luminaires is reusable and recyclable, which is why they have the Eco Friendly Design label that also accompanies other products that see cork as an ally in the transition towards more sustainable circular production models.
