Factors Affecting the Breathability of Fabrics
Fabrics factors:
Fiber morphology and yarn structure: When the linear density of the warp and weft yarns and the arrangement density of the warp yarns are the same, non-circular cross-section fiber fabrics are superior to circular cross-section fiber fabrics. The fabric with thicker single fibers has better ventilation than the one with thinner single fibers.
2. Fabric structure: Under the same conditions of arrangement density and tightness, the order of breathability from high to low is plain weave < diagonal weave < satin weave < porous fabric.
3. Post-treatment of fabrics: Fabric dyeing and finishing, resulting in tighter fabric structure and decreased breathability; Reduction treatment, causing the fabric fibers to become finer, increasing the pores between fibers and yarns, and enhancing the breathability.
Environmental factors:
When the temperature is constant: The ventilation capacity of the fabric decreases as the relative humidity of the air increases. After the fabric absorbs water, the fibers expand and the air pores contract, resulting in a reduction of internal pores in the fabric. The pores in the fabric become blocked, causing the ventilation capacity of the fabric to decrease.
2. When the relative humidity remains constant, the ventilation capacity of the fabric increases as the environmental temperature rises. The thermal motion of gas molecules intensifies, thereby enhancing the diffusion ability of the molecules.
3. When the temperature and relative humidity remain constant, the air pressure P on both sides of the fabric changes, which will affect the measured flow rate, and the influence is non-linear.