What Is Air Permeability?
Air permeability test is the measurement of air flow rate passing through unit area in unit time by creating a constant pressure difference between the two sides of the fabric. The result is usually given in mm/s or L/m²/s and is directly related to the pore structure of the fabric.
Purpose of Air Permeability
The aim is to numerically determine the breathability, filtration behavior or windproofness of the fabric. The same measurement is a desired target to be high in some products and low in others.
Which Products Is Air Permeability Applied To?
- Filter fabrics and nonwovens
- airbag fabrics
- Sports and outdoor clothing fabrics
- Duvet, pillow and covering fabrics
- Parachute and technical textiles
In Which Sectors Is Air Permeability Used?
Standards Related to Air Permeability
- TS EN ISO 9237 (air permeability in fabrics)
- ASTM D737
- TS EN ISO 9073-15 (non-woven surfaces)
Air Permeability Conditions
- pressure difference
- Values defined in the standard; 100 Pa is commonly used in clothing fabrics, different values are used in technical textiles
- test area
- Header area of the device; reported with the result
- Conditioning
- ISO 139 standart atmosferinde
- Repeats
- A minimum of ten measurements distributed over the fabric surface is recommended
Equipment for Air Permeability
- air permeability tester
- Interchangeable measuring heads
- Pressure and flow measurement system
- Conditioning chamber
Sample Requirements for Air Permeability
- Measuring points distributed across fabric width and length
- The sample must be large enough to cover the head completely.
- Edges and seamed areas should not come into the measurement area.
- For coated fabrics, it must be stated which side will be on top.
Duration of Air Permeability
Measurement is fast; The total time is determined by the number of measurement points and conditioning.
Air Permeability Procedure
- 1The specimen is conditioned.
- 2Device head and pressure difference are adjusted according to the standard.
- 3The sample is clamped into the head to prevent leakage.
- 4The air flow rate passing through a defined pressure difference is measured.
- 5The measurement is repeated at different points.
- 6The mean, standard deviation and coefficient of variation are calculated.
Air Permeability Acceptance Criteria
The acceptance criterion is the flow rate range in the product standard or customer specification. Filter applications may have both lower and upper limits.
Evaluation of Results
The distribution between measurement points shows the structural evenness of the fabric. If the pressure difference and test area are not provided with the result, the data cannot be compared; The results obtained at different pressures are not proportional.
Air Permeability Report
- Sample description and fabric structure
- Applied pressure difference and test area
- Individual measurements, average and coefficient of variation
- Conditioning conditions
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- EU 1007/2011 (textile fibre names and labelling)
- EU 1907/2006 REACH Annex XVII (restricted substances in textiles)
- Regulation on the Naming of Textile Products
Tekstil Testleri — What Does This Testing Field Cover?
The section below describes the field that the Air Permeability test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Textile testing answers two questions separately: does the fabric hold up physically over its service life, and does it carry any substance restricted for human health? These two axes require different laboratory infrastructure and different decision mechanisms.
On the physical side, breaking and tear strength, abrasion resistance, pilling, dimensional change, colour fastness and water and oil repellency are measured. Most of these tests depend on the USE SCENARIO: Martindale abrasion cycles are decisive for an upholstery fabric, while dimensional change in washing and colour fastness come to the fore for a shirting fabric. The same fabric goes through a different test set for a different use.
Colour fastness is a body of work of its own in this field and is not a single test. The fastness of the same fabric to light, washing, rubbing, perspiration, saliva, chlorinated water and ironing is measured separately; each represents a different moment of use. Results are rated from 1 to 5 on the grey scale and the specification gives a separate minimum rating for each agent.
On the chemical side, aromatic amines released from azo dyes, formaldehyde, heavy metals, phthalates, short-chain chlorinated paraffins, alkylphenols and PFAS compounds are screened. These items come from REACH restrictions, brand restricted substance lists (RSL) and voluntary schemes such as OEKO-TEX. Brand lists are often stricter than legislation; the target customer is decisive.
There is NO CE marking on consumer textiles. The obligation has three legs: fibre composition and care labelling, compliance with chemical restrictions, and general product safety. Textiles claiming a protective function (workwear, flame-resistant clothing, high-visibility clothing) fall under personal protective equipment legislation, where CE is mandatory — this distinction is commercially critical.
Verifying the label declaration is the most routine work in the field. Quantitative fibre analysis confirms the blend ratio stated on the label; tolerance ranges are defined in legislation. An incorrect fibre declaration both misleads the consumer and affects customs classification.
Sustainability claims have added a new body of work to the field in recent years: verification of recycled content (GRS, RCS), organic content (GOTS), restriction of harmful chemicals and water/energy footprint declarations. These claims now require auditable evidence.
Method groups in this field
Strength and durability
Strip and grab breaking strength, tearing by the Elmendorf and tongue methods, seam strength, bursting strength.
Abrasion and surface
Martindale and rotary platform abrasion, pilling and fuzzing, fabric mass and thread density measurements.
Dimensional stability
Dimensional change in washing and drying, wrinkling behaviour, appearance after ironing.
Colour fastness
Fastness to light (xenon), washing, rubbing, perspiration, saliva, water and chlorinated water; rating on the grey scale.
Functional properties
Water repellency (spray test), oil repellency, waterproofness, air permeability, effectiveness of antibacterial finishes, UV protection factor.
Chemical analyses
Aromatic amines from azo dyes, formaldehyde, pH, heavy metals, phthalates, chlorinated phenols, PFAS and alkylphenols.
Commonly confused in this field
- A brand restricted substance list (RSL) may be stricter than legislation; REACH compliance does not mean compliance with the customer specification.
- Textiles claiming a protective function fall under PPE legislation and require CE; an ordinary textile test report does not satisfy that file.
- Colour fastness is not a single number; a rating cannot be interpreted without stating which agent it relates to.
- A result obtained for a fabric does not cover the whole garment made from it; lining, sewing thread, print and trims are assessed separately.
- Performance claims after washing are valid together with the stated number of wash cycles; the word "permanent" on its own is not verifiable.
Which decisions these results support
- Compliance with the brand restricted substance list (RSL)
- Verification of label declarations: fibre composition and care instructions
- Determining the performance class of upholstery and technical textiles
- Pre-import shipment inspection and lot acceptance
- Supporting sustainability and recycled content claims
Related Tests
Frequently Asked Questions About Air Permeability
Is air permeability the same as breathability?
It is not the same. Air permeability measures the passage of air through a fabric; Breathability is the transmission of water vapor and is measured with a separate test (vapor permeability). While membrane fabrics are airtight, they can permeate water vapor.
Why are so many measuring points required?
Air permeability is very sensitive to the pore structure of the fabric and single point measurement is misleading. Even small differences in weaving density change the result; therefore, multiple measurements distributed over the surface are averaged.