NewsInformation Center
How do you test for air permeability of fabric?
2023/08/24
Share:
The air permeability of fabric is commonly tested using methods like the "Gurley method," "Shirley air permeability test," or the more widely recognized "ASTM D737" test method. These methods measure the ease with which air is allowed to pass through a fabric sample under specific conditions. Here is a general overview of the ASTM D737 test method:
1. Sample Preparation: Cut representative fabric samples into circular or square shapes with specified dimensions. Typically, a minimum of three samples is tested to ensure accuracy and account for any variations.
2. Conditioning: Condition the fabric samples in a controlled environment, usually at standard testing conditions (e.g., 65% relative humidity and 21°C), to stabilize their moisture content and temperature.
3. Test Apparatus: Set up the air permeability test apparatus, which typically consists of a testing chamber, an air supply system, and a differential pressure gauge. The chamber has a defined area through which the fabric sample will be placed.
4. Test Procedure:
a. Place the fabric sample over the testing chamber's opening, ensuring it covers the entire area without any wrinkles or gaps.
b. Apply a specified pressure difference across the fabric (typically 125 Pascals or 2 inches of water). This pressure simulates the typical conditions experienced by the fabric during use.
c. Allow the air to flow through the fabric for a specific time (usually a few seconds) to establish a steady-state airflow.
d. Measure the airflow rate (expressed in cubic feet per minute or liters per square meter per second) using the differential pressure gauge or a calibrated flow meter.
e. Repeat the test for all the fabric samples.
5. Calculation and Reporting: Calculate the average air permeability values based on the airflow rates obtained from the multiple fabric samples. Report the results in the appropriate units (e.g., CFM or L/m²/s) along with any other relevant information such as sample dimensions and test conditions.
It is important to note that specific industries or applications may have their own standardized testing methods or variations of the above-mentioned methods. Also, different countries may have their own equivalent national standards similar to ASTM D737.
To ensure accurate and reliable results, it is recommended to follow the specific test methods provided by recognized standards organizations (such as ASTM International or ISO) or consult appropriate industry guidelines.
Professional testing laboratories, research institutions, and some fabric manufacturers typically have the necessary equipment and expertise to perform air permeability testing. Additionally, there are specialized instruments available that can automate the measurement process.
If you require precise and validated air permeability values for a particular fabric, it is advisable to consult experts, testing laboratories, or refer to recognized testing standards for the most accurate and consistent results.
Previous: Do you know what is the UL 94 Standard of testing?
N e x t : How do you do a rub resistance test?
