Benefits of Cork
These physical properties provide cork all the famous advantages:
Light weight: Due to the fact that more than 50 % of the cell volume of a cork piece consists of air, cork is one of the lightest solid substances, with a specific gravity of .25.
A cubic inch of cork can withstand as great a pressure as 14,000 lbs. per square inch without breaking, and retains 90% of its original form after the pressure is released. Less or more normal pressure increase return to original form from 97% to 100%.
Because heavy pressure does not break down or destroy the tiny air cells, but compresses the air within the cells, the cork begins to spring back when the pressure is removed. A roll or sheet of composition cork can be compressed in one direction without losing its dimensions in the other direction. This is of great importance for many applications of composition cork.
RESISTANCE TO MOISTURE AND LIQUID PENETRATION
While cork is not completely impervious to moisture penetration, its cellular structure gives it a high resistance to penetration by water which with the addition of the proper binder can be proofed.
Cork is a highly frictional material, both in its natural form as well as in cork composition. Even when wet or coated with oil or grease, cork retains this quality which surpasses that of leather, rubber, and many other products used for frictional or non-skid purposes.
LOW THERMAL CONDUCTIVITY
Next to a vacuum, a “dead” air space minutely divides one of the most efficient non-conductors of heat. The cell construction of cork provides this property for which cork is so famous.
ABILITY TO ABSORB VIBRATION
Cork, with its 200 million air cells per cubic inch; of which 50% is air, essentially acts as an “air cushion”, absorbing vibrations and direct impacts.
Cork is a tough, durable substance with remarkable capacity for retaining its initial properties wherever recommended. The high degree of stability under varying conditions is paramount to the continuing success and use of cork in the world today.