What is the appropriate air permeability of the fabric

The standard requires that the air permeability of the fabric shall be ≤ 50mm / s.

Air permeability affects the wearing comfort of the fabric, such as heat insulation and warmth preservation. Fabric permeability is an important way for human body to transmit heat, gaseous moisture, carbon dioxide and other gases to the outside world

Definition of air permeability

Permeability refers to the permeability of gas to polymer materials such as films, coatings and fabrics.

Fabric permeability refers to the performance of air passing through the fabric when there is a pressure difference on both sides of the fabric.

That is, the volume of air flowing through the unit area of the fabric per unit time under the specified pressure difference on both sides of the fabric. The common unit is mm / s. Because the pressure difference is a necessary condition for air flow, only by maintaining a certain pressure difference on both sides of the tested fabric can air flow be generated in the fabric.