In the world of textiles, performance evaluation is critical. One of the most important properties that determines the usability of fabrics—especially in activewear, medical textiles, industrial filters, and technical fabrics—is air permeability. Accurate testing ensures that materials meet their required specifications for breathability, burst strength of corrugated boxes, comfort, and functionality. Among the leading instruments used for this purpose is the Shirley Air Permeability Tester, a reliable and widely respected tool in the global textile testing industry.
In this article, we will explore everything you need to know about the Shirley Air Permeability Tester—from its working principle to its applications, advantages, testing standards, and how it compares to other types of permeability testing machines on the market.
What is Air Permeability
Air permeability refers to the ability of a fabric to allow air to pass through it. It is expressed in units such as cm³/cm²/s or L/m²/s under a specified pressure differential. This parameter is vital for determining the performance of textiles used in various industries:
- Sportswear and outdoor clothing: Breathability for thermal comfort
- Technical textiles: Filtration efficiency and pressure drop
- Medical textiles: Airflow through surgical gowns and drapes
- Automotive and aerospace: Seat and panel ventilation
- Geotextiles and construction materials: Air and moisture transfer regulation
To assess this property accurately, specialized instruments like the Shirley Air Permeability Tester are employed.
Introducing the Shirley Air Permeability Tester
The Shirley Air Permeability Tester is a well-established instrument used globally to evaluate the air permeability of fabrics, nonwovens, and other porous materials. Manufactured by renowned textile machinery companies, the Shirley tester is known for its robust construction, accurate results, and ease of operation.
It operates by measuring the volume of air that passes through a given area of fabric under a controlled pressure difference. The results are displayed either digitally or on a calibrated scale, depending on the model.
How Does the Shirley Air Permeability Tester Work?
The working principle of the Shirley tester involves the following steps:
- Sample Mounting: A fabric sample is clamped securely in the test head, ensuring an airtight seal.
- Pressure Application: A defined pressure difference (typically 10, 50, or 100 Pa) is applied across the sample.
- Airflow Measurement: The volume of air passing through the sample per unit time is measured.
- Result Calculation: The device calculates and displays the air permeability result based on standard units.
This simple yet precise method has made the Shirley model a staple in textile labs and R&D centers worldwide.
Why Choose the Shirley Air Permeability Tester?
There are several reasons why laboratories and quality assurance teams prefer the Shirley Air Permeability Tester:
- High Accuracy and Repeatability: Engineered for consistency, it delivers reliable data across multiple test runs.
- User-Friendly Operation: Clear interface and easy sample mounting make it ideal for both experienced technicians and beginners.
- Compliance with Standards: It supports a wide range of international testing standards including ASTM D737, ISO 9237, BS 5636, and DIN 53887.
- Versatility: Suitable for woven, knitted, and nonwoven fabrics, as well as paper, filter materials, and synthetic membranes.
- Durability: Built with industrial-grade components for long-term use in high-throughput labs.
Testing Standards Supported by Shirley Air Permeability Tester
The Shirley tester is compatible with the following global test methods:
| Standard | Description |
| ASTM D737 | Standard Test Method for Air Permeability of Textile Fabrics |
| ISO 9237 | Textiles – Determination of the Permeability of Fabrics to Air |
| BS 5636 | Determination of the Air Permeability of Fabrics |
| DIN 53887 | Determination of Air Permeability in Textiles |
These standards specify sample sizes, pressure differentials, and result interpretation, ensuring that your test results are accepted globally.
Applications of Air Permeability Testing in Different Industries
1. Apparel Industry
Garments for sports, outdoor, and workwear require breathable fabrics to ensure user comfort. Air permeability tests help determine if the fabrics can regulate airflow and moisture effectively.
2. Medical and Hygiene
Fabrics used in surgical gowns, masks, and hygiene products must balance filtration with breathability. The Shirley tester is widely used to evaluate such materials.
3. Automotive and Aerospace
Interior textiles like seat covers and headliners benefit from controlled air permeability for enhanced comfort and functionality.
4. Industrial Filters
Filter media must allow airflow while trapping particles. Testing with a permeability testing machine ensures that these requirements are met consistently.
5. Construction and Geotextiles
Fabrics used in roofing, insulation, or soil stabilization need proper air and moisture permeability to function effectively in diverse environmental conditions.
Comparing the Shirley Air Permeability Tester with Other Permeability Testing Machines
While the Shirley tester is a respected and trusted option, it’s important to understand how it compares to other types of permeability testing machines available in the market:
| Feature | Shirley Tester | Modern Digital Testers | Automated Robotic Testers |
| Operation | Manual/Semi-digital | Fully Digital | Fully Automated |
| Precision | High | Very High | Very High |
| Cost | Moderate | High | Very High |
| Maintenance | Low | Moderate | High |
| Suitability | General Purpose | Advanced R&D | High-Volume Production |
For laboratories prioritizing accuracy and standard compliance without excessive investment, the Shirley Air Permeability Tester remains a strong contender.
Factors to Consider Before Buying a Permeability Testing Machine
Whether you’re selecting the Shirley model or another air permeability tester, here are some key factors to evaluate:
- Compliance with Test Standards: Make sure the machine supports relevant international standards.
- Measurement Range: Choose an instrument that matches the expected permeability range of your materials.
- Automation Level: Consider the level of automation that fits your lab’s workflow and volume.
- Data Output and Analysis: Digital output and software integration can significantly improve efficiency.
- After-Sales Support: Choose a supplier that offers installation, calibration, and maintenance services.
Environmental and Quality Control Considerations
Air permeability can be influenced by environmental conditions such as temperature, humidity, and sample pre-conditioning. The Shirley tester should be used in controlled lab environments to ensure repeatability and accuracy.
Additionally, periodic calibration and use of reference materials can further enhance confidence in your results.
Final Thoughts
The Shirley Air Permeability Tester is a time-tested, reliable, and cost-effective solution for fabric permeability evaluation. Whether you’re in a research lab, a textile manufacturing facility, or a third-party testing organization, it delivers consistent performance and meets global testing standards.
In the era of functional and technical textiles, understanding and optimizing air permeability has never been more important. Investing in a quality permeability testing machine like the Shirley tester not only ensures product compliance but also builds customer trust and enhances brand credibility.
For more information on textile testing methods/standards
or textile testing machine-TESTEX textile testing machines, contact us:
What’s App: +86 180 2511 4082
Tel: +86 769 2329 4842
Fax: +86 769 2329 4860
Email: sales@tes.hk