How is the breathability mechanism of Functional Air-through Non-woven Fabric achieved?

Functional Air-through Non-woven Fabric is a material with excellent breathability, which is widely used in medical and health, personal care and industrial protection. Its breathability mechanism is mainly achieved through fiber structure design, web forming process optimization and post-processing technology. The following is a detailed analysis of the formation principle and influencing factors of its breathability from multiple perspectives:

Fiber arrangement and pore structure
Microporous network: The breathability of functional breathable non-woven fabrics depends on the microporous network formed by the gaps between fibers. These micropores allow air molecules to pass through while blocking larger particles or liquids from penetrating.
Fiber diameter and spacing: Finer fibers and appropriate spacing can form more micropores, thereby improving breathability. For example, ultrafine fibers produced by meltblowing process have high specific surface area and dense microporous structure, which is very suitable for making efficient breathable materials.
Three-dimensional structure: Some non-woven fabrics use three-dimensional fiber arrangement to increase the air circulation channel inside the material, further improving the breathability effect.
Influence of web forming process
Meltblowing method: The meltblowing process stretches the molten polymer into ultrafine fibers through high-speed airflow and randomly deposits them to form a fiber web. The nonwoven fabric produced by this process has extremely high porosity and uniform micropore distribution, which is an important source of breathability.

Spunbond: The spunbond process forms a coarser fiber web through continuous spinning and drawing. Although the pore size is large, the air permeability and strength can be balanced by adjusting the fiber density.
Hydroentanglement: The hydroentanglement process uses high-pressure water flow to reinforce the fiber web, so that the fibers form a tight and orderly connection. This method can retain a certain air permeability while ensuring strength.
Needle punching: The needle punching process compacts the fiber layer through mechanical needle punching to form a three-dimensional structure with a certain porosity. This process is suitable for manufacturing high-strength and breathable functional nonwoven fabrics.
The role of post-processing technology
Surface modification: Hydrophilic or hydrophobic treatment of the surface of nonwoven fabrics can change its air permeability. For example, hydrophilic coatings help absorb moisture and accelerate evaporation, thereby indirectly improving air permeability.
Hot rolling or chemical bonding: These reinforcement methods bond the fibers together through local heating or chemical reagents to form a stable pore structure. A moderate degree of bonding can ensure a balance between breathability and strength.
Multi-layer lamination: Laminating nonwoven layers with different functions, such as adding a waterproof membrane or antibacterial layer outside the breathable layer, can achieve more functions without sacrificing breathability.
Influence of material selection
Polypropylene (PP): Polypropylene is one of the most commonly used raw materials for nonwoven fabrics. It can form a uniform microporous structure due to its good flexibility and processability.
Polyester (PET): Polyester fiber has higher strength and heat resistance and is suitable for scenarios that require higher durability. However, its breathability may be slightly inferior to polypropylene.
Bio-based materials: New bio-based fibers (such as PLA or cellulose) are gradually being used in nonwoven fabric production. These materials are not only environmentally friendly, but may also have unique breathability.
Trade-off between breathability and other properties
Breathability vs. waterproofness: Improving breathability may reduce the waterproof ability of the material, and vice versa. Therefore, when designing functional nonwovens, it is necessary to find the best balance according to the specific application scenario. For example, medical masks need to balance breathability and filtration efficiency.
Breathability vs. Strength: Too many micropores may lead to a decrease in material strength, so this problem needs to be solved by optimizing fiber arrangement and reinforcement process.

The breathability mechanism of functional breathable nonwovens is mainly achieved through the combined action of fiber arrangement, web forming process and post-processing technology. The core is to build a uniform and stable microporous network that allows air molecules to flow freely while meeting specific application requirements.