Breathability
A good outdoor garment should not only be rainproof but also breathable. Its breathability is determined by the microporous structure of the membrane, allowing gaseous water molecules to escape while preventing liquid water molecules from entering. Breathability is the ability of air to pass through a fabric. It is expressed as the rate at which airflow passes vertically through the sample under specified test area, pressure drop, and time conditions. The unit is mm/s or m/s. The higher the value, the better the breathability. GB/T5453–1997, "Determination of Air Permeability of Textile Fabrics," recommends a test area of 20 cm², but 5 cm², 50 cm², or 100 cm² can also be used; the pressure drop is 100 Pa for apparel fabrics and 200 Pa for industrial fabrics. If the above pressure drops are insufficient or unsuitable, 50 Pa or 200 Pa can be used after consultation with all relevant parties.
Quick-drying property
Moisture absorption and quick-drying property refers to the ability to quickly absorb sweat produced by the body, expel it to the outer layer as much as possible, and evaporate it quickly, keeping the body as dry as possible.
GB/T21655.1–2008, "Evaluation of the Moisture Absorption and Quick-Drying Properties of Textiles - Part 1: Single-Item Combination Test Method," characterizes the fabric's ability to absorb liquid sweat using the water absorption rate, drip diffusion time, and wicking height; and characterizes the fabric's quick-drying properties in liquid sweat using the moisture evaporation rate and moisture permeability under specified air conditions. This standard provides specific technical requirements for knitted and woven products explicitly labeled as moisture-absorbing and quick-drying.
GB/T21655.2–2008, "Evaluation of the Moisture Absorption and Quick-Drying Properties of Textiles - Part 2: Dynamic Moisture Transfer Method," specifies the following test method: the fabric sample is placed horizontally, and after liquid water comes into contact with its immersed surface, the liquid water diffuses along the immersed surface and transfers from the immersed surface to the permeated surface, while simultaneously diffusing on the permeated surface. The change in moisture content is a function of time. After the test liquid is dropped onto the water-immersed surface of the sample, the dynamic transfer of liquid water is measured using a sensor that is in close contact with the sample. A series of performance indicators are then calculated to evaluate the moisture absorption, quick-drying, and perspiration-wicking properties of the textile.
