Characteristics of Cork

As a high-quality and multi-functional raw material, cork stands out for its structure and chemical composition which gives it unique properties:

  • Lightness and buoyancy, with a density of around 24kg/dm3.
  • Impermeability to liquids and gases, due to the presence of suberin, which means it does not rot, making it one of the best insulation materials in existence.
  • Elasticity and Flexibility. Cork’s cellular membranes are highly flexible, making it compressible and elastic. This means that after being subjected to pressure, cork returns to its original form, because the gas inside its cells compresses, significantly reducing its volume. When the pressure is lifted, the cork regains its original shape and volume, without becoming deformed. This is one of the characteristics which has made it indispensible in the manufacture of cork stoppers and other high-quality seals.
  • Resistance to wear and tear, friction and longevity. Cork is extraordinarily resistant to wear and tear and has a high attrition coefficient. Thanks to its honeycomb structure, it is less affected by impacts or attrition than other hard surfaces.
  • Low electrical conductivity. 0.074W/mK (0.063 Kcal/mhºC) SIA – 279 lambda coefficient 0.040.
  • Low sound and vibration conductivity; cork acts as an acoustic corrector, reducing sound volume by an average of 20 to 30dB depending on frequency. This is because it contains gaseous elements which are sealed inside small impermeable compartments isolated from one other.
  • Good thermal insulator (thermal resistance of -180ºC to 110ºC).
  • Cork is also a natural fire retardant; it does not catch fire nor emit toxic gases during combustion.
  • It is chemically and biologically very stable. It is chemically inert and has hypoallergenic properties because it does not absorb dust. Its composition does not alter which guarantees efficiency and poses no risk to people suffering from respiratory allergies.