What is the air permeability test ASTM D737?

 

The test determines the ease with which air can pass through a fabric. This property is essential in various applications, such as clothing, filtration, and industrial materials. The test method provides a quantitative measurement of air permeability, which is expressed in units of cubic feet per minute per square foot (cfm/ft²) or liters per square meter per second (L/m²/s).

 

 

1. Test Specimen Preparation: Fabric samples of a specific size are required for testing. The specimens are conditioned in a controlled environment to achieve consistent test conditions.

 

2. Instrument Setup: The test is performed using an air permeability testing apparatus, such as a Textile Air Permeability Tester. The tester consists of a fixed area opening, a differential pressure gauge, and a controlled air flow system.

 

3. Specimen Mounting: The fabric sample is securely mounted over the opening of the test apparatus, ensuring a tight seal to prevent air leakage around the edges.

 

4. Testing Procedure: A constant air pressure is applied to one side of the fabric specimen, while the other side is exposed to atmospheric pressure. The air flow rate passing through the fabric is measured using the differential pressure gauge. This gauge measures the pressure drop across the fabric caused by the air flow.

 

5. Calculation of Air Permeability: The air permeability value is calculated using the recorded pressure drop and the known dimensions of the fabric sample. The result is expressed in cfm/ft² or L/m²/s.

 

The ASTM D737 test method provides a standardized procedure for assessing the air permeability of textile fabrics. This information is valuable for manufacturers, researchers, and end-users to evaluate the breathability, ventilation, and overall performance of fabrics in different applications.