The Role of Nonwoven Fabric Breathability in the Textile Industry

The Role of Nonwoven Fabric Breathability in the Textile Industry

Nonwoven fabric, named for being produced without traditional weaving or knitting, is a new generation of eco-friendly material. It offers advantages such as breathability, flexibility, non-toxicity, odorlessness, and low cost, leading to its widespread use in many fields, including agricultural films, shoemaking, leather processing, mattresses, chemicals, automobiles, and construction materials. In the medical and health industry, it is used to produce surgical gowns, protective clothing, adhesive bandages, sterilization packaging, masks, sanitary napkins, and more. Among its many applications, good breathability is a key reason for its broad adoption. Taking medical industry products as an example: if the breathability of nonwoven fabric is poor, adhesive bandages made from it may fail to meet the skin's normal respiratory needs, causing allergic reactions in users. Poor breathability in medical tapes like bandages can lead to microbial growth around wounds, resulting in infection. Low breathability in protective clothing significantly reduces wearing comfort. Similar to medical products, poor breathability in other nonwoven products also brings many disadvantages. Therefore, enhancing the testing of nonwoven fabric breathability is a crucial measure to ensure that related products meet usage requirements.

Testing Standard:

The breathability (air permeability) involved in the test characterizes the ability of air to pass through a sample. The testing process can follow the standard GB/T 5453-1997 Textiles – Determination of Breathability of Fabrics, which applies to various textile fabrics, including industrial fabrics, nonwovens, and other permeable textile products.

Test Principle:

There are two main methods for testing air permeability: constant pressure difference with flow measurement, and constant flow with pressure difference measurement. The constant pressure difference method maintains a fixed pressure difference across the sample, measuring the airflow volume passing through a given area of the sample over a set time to calculate air permeability. The constant flow method keeps the airflow perpendicular through the sample constant, measuring the resulting pressure difference to determine air permeability. The testing described in this article uses the constant pressure difference method.

Equipment Parameters:

1. Pressure difference measurement range: 0–1 KPa; airflow measurement range: 0–1800 L/h.

2. Both constant pressure difference and constant flow measurement modes are available for users to choose according to different testing needs.

3. High-precision electronic airflow and air pressure sensors ensure accurate test data.

4. The system is controlled by a microcomputer with an LCD display, menu-based interface, and PVC control panel, allowing users to quickly perform test operations and view data.

Applicable Scope:

(1) Air permeability testing of textile materials, such as fabrics and nonwovens.
(2) Testing air permeability and air resistance of automotive interior materials, such as polyurethane, PVC, leather, textiles, and nonwovens.
(3) Testing air permeability of porous polymer elastic materials, such as foam.
(4) Air permeability testing of leather materials.
(5) Can be extended to test air permeability of paper materials, such as household tissues and toilet paper rolls.
(6) Complies with multiple national and international standards, including GB/T 5453, ISO 9237, ISO 4638, ISO 5636, GB/T 10655, GB/T 4689.22, GB/T 13764, ASTM D737, TAPPI T460, JIS P8117, etc.

Test Procedure:

(1) Randomly cut 10 samples with a diameter of 50 mm (diameter can be selected based on specific conditions) from the surface of a medical nonwoven fabric sample.
(2) Clamp one sample into the air permeability tester, ensuring it is flat without deformation and that both sides are well sealed.
(3) Set the pressure difference across the sample according to the sample's breathability or relevant standards. In this test, the set pressure difference is 100 Pa. Adjust the pressure control valve to achieve the set pressure difference. When the pressure difference reaches the set value, the test stops. The device automatically displays the airflow through the sample.
(4) Repeat the clamping and pressure adjustment steps until all 10 samples are tested.

Test Results:

The average air permeability of the medical nonwoven fabric samples tested was 16.13 L/h (average of the 10 samples). Both the diameter of the cut samples and the set pressure difference affect the results. Therefore, when comparing the breathability of different nonwoven samples, the sample diameter and pressure difference must be kept consistent.

Breathability is one of the excellent properties of nonwoven materials and an important factor affecting the safety, hygiene, comfort, and other performance characteristics of nonwoven products. In this article, a breathability tester was used to evaluate the air permeability of medical nonwoven fabric. The test process is simple, the equipment is easy to operate, and the results show good repeatability and accuracy, with high measurement precision, reliably reflecting the breathability of the tested samples.