Is air permeability the same as air tightness?

 

1. Breathability: Breathability is the ability of a textile to allow air to pass through. It reflects the extent to which a textile is permeable and ventilated to gases. Breathability depends on the structure and porosity of the textile, as well as the resistance between the textile and the gas. A textile with better breathability promotes air circulation and facilitates the expulsion of moisture and heat from the body, providing better comfort and breathability.

 

2. Airtightness: Airtightness refers to the ability of a textile to prevent the penetration of gases. It reflects the degree of obstruction to gas permeation and leakage. Airtightness is usually assessed by measuring the permeability or pressure difference of a textile to a gas. Textiles with better gas tightness effectively prevent the penetration of gases and are suitable for demanding applications that require waterproofing, windproofing and sealing.

 

Distinctions:

 

1. Functional objective: The primary functional objective of air permeability is to facilitate air circulation and ventilation, providing comfort and breathability. The main functional objective of airtightness is to prevent gas permeation and leakage, and to realize the effect of waterproof, windproof and sealing.

 

2. Measurement method: Breathability is usually assessed by measuring the rate of gas transmission or air permeability on textiles. The airtightness is usually evaluated by measuring the permeability or air density of the gas on the textile.

 

3. Areas of application: Textiles with better air permeability are suitable for applications that require air permeability, such as sportswear and outdoor products. Whereas textiles with better gas permeability are suitable for applications requiring waterproof, windproof and sealing performance, such as raincoats, tents, protective clothing, etc.

 

It should be noted that breathability and airtightness are not completely mutually exclusive concepts. Certain textiles can be both breathable and airtight to a certain extent, balancing the two according to different needs and applications. In addition, the assessment of breathability and airtightness needs to take into account other factors such as humidity, temperature and pressure. Therefore, when selecting textiles, a combination of air permeability and airtightness requirements need to be considered for optimal performance and functionality depending on the specific needs and application environment.