1. Low density and lightness. Cork cells are 90% occupied by air.
2. Waterproofing. The suberine and the waxes present in the cell wall make the cork practically impermeable to liquids and gases. Holes in the hexagonal shape of your wall full of air make it inaccessible to other compounds.
3. Low heat transfer and good thermal insulation. The high gas content, the size of the cells and the low adsorption power make this property.
4. Acoustic insulation and low sound transmission. Low density and high porosity make the majority of the waves of sound adsorbable and transform into heat energy. Cork is an acoustic corrector since it absorbs more than 60% of the sound waves that affect the surface.
5. High resistance to movement or high coefficient of friction. The suction effect caused by the surface of the cells makes it a very important property when it comes to using cork as a covering material.
6. Cushioning capacity. It is given by the deformation by flexion of the cell walls and is a very important property for some applications such as the caps or soles of shoe.
7. Compressibility, elasticity and flexibility. The high air content of its cells allows it to be compressed to almost half without loosing flexibility, and recovering its shape and volume when it stops pressing. It is the only solid that if compressed on one side, does not increase by the other.
8. Durability, stability and rigidity. Lignin and the polysaccharides of its cell wall provide it with rigidity and make it resistant over time.
9. Higroscopic. Hydrated according to the environmental conditions.
10. 100% natural, recyclable and renewable. It is a vegetable material that can be extracted without hurting the tree and regenerating over the years. It allows a sustainable balance between agroforestry management and the action of man. In line with the current tendencies of natural materials and sustainable construction. It is a clear example of a circular economy.
PROPERTIES OF THE SURO WITHOUT CREATING OR TREATING OR MODIFYING
Some of its physical and mechanical properties are due to the structural characteristics at the cellular level and the chemical structure of the plant wall (more than 40% of suberine, lignin and polysaccharides).
Density: 120-200kg · m-3
Thermal conductivity: 0.045Wm-1k-1
Acoustic resistance: 1.2 · 105kgm-2s-1
Coefficient of friction: 0.35-0.76 cork / glass
Coefficient of water diffusion: 2.6-2.9 · 10-9 m-2s-1
Electrical conductivity: 1.2 · 10-10Sm-1 at 25ºC; 1.67 · 10-13Sm-1 at 50ᵒC