What is Air Permeability?

Air Permeability

 

At Acadian Industrial Textiles, our goal is to help you sell more products. And the most effective way to sell anything is to make sure the products you recommend are appropriate for your customers’ needs.

In this blog series, we provide information about the technical specifications and testing criteria for our industrial textiles. The more you know about how these fabrics work and which applications they’re best suited for, the better you can sell them!

What is air permeability?

Air permeability measures how easily air is passed through fabric. It indicates the breathability of weather-resistant and waterproof fabrics and is an important factor in the performance of materials like industrial curtains, sails, airbags and parachutes.

The main influences on air permeability are the density of the material and its structure. Fabrics can be coated to modify their air permeability.

Let’s get technical

Air permeability is defined by the volume of air in cubic centimeters (cm3) which is passed through in one second through 100cm2 of the fabric at a pressure difference of 10cm head of water.

How a fabric’s air permeability is tested:

  • The airflow through an area of fabric is measured at a constant pressure drop across the fabric of 10cm head of water
  • The specimen is clamped over the air inlet using rubber gaskets and air is sucked through it by a pump
  • The air valve is adjusted to give a pressure drop across the fabric of 10cm head of water, then the airflow is measured with a flow meter
  • The mean airflow in cm3 per second is calculated from the results of five test specimens
  • The air permeability is then calculated in cm3 per second per cm2

Importance of air permeability

Air permeability is particularly important for insect netting when used on greenhouse structures. Because greenhouses use fans and blowers to ensure adequate airflow for the plants, if there is too much airflow resistance the fans will be loaded more than necessary, causing them to burn out prematurely.

What if I still need help?

That’s what we’re here for. If you ever have questions about how to choose the right fabric for a customer, or how to navigate and interpret various technical specifications, we are more than happy to help.