Are There Any Waterproof And Breathable Clothes?

Are there any waterproof and breathable clothes?

2022-11-30 17:04:51

Mountaineering is a sport that many people like. When you climb a mountain, it may rain, but it is inconvenient to climb with an umbrella. Moreover, mountain climbing is a very physical activity. When you sweat a lot, the temperature on the mountain is usually very low, and undressing is unrealistic. Therefore, a waterproof and breathable clothing is particularly important for mountaineers.

Do you have waterproof and breathable clothes? In fact, people have been studying this problem for a long time. Usually people call it vapor permeable fabric, but it is not the gas in the air, but the steam evaporated from sweat.

Waterproof and moisture permeable fabric refers to that water does not immerse into the fabric under certain pressure, while sweat emitted by the human body can be transmitted to the outside world through the fabric in the form of water vapor, so as to prevent sweat from accumulating and condensing between the body surface and the fabric to maintain the comfort of the clothing.

Waterproof is not a problem, the key is how to achieve moisture permeability. Let's talk about perspective together.

Definition of fabric moisture permeability

The moisture permeability of the fabric refers to the mass of water vapor passing through the sample per unit area vertically within the specified time on both sides of the fabric under the condition of maintaining the specified temperature and humidity.

The principle of the test is to place the moisture permeable cup filled with moisture absorbent or water and sealed with a fabric sample in a sealed environment with specified temperature and humidity, and calculate the moisture permeability indicators of the sample according to the change in the quality of the moisture permeable cup within a certain period of time.

As a necessary artifact for mountaineering, the trench coat is a typical garment made of waterproof and moisture permeable textile fabrics.

Influencing factors of fabric moisture permeability.

(1) An important way of fabric moisture transmission is that the fiber on the side contacting the high humidity air absorbs moisture from the high humidity air, and the moisture is transferred from the fiber to the other side of the fabric and releases moisture to the low humidity air. Therefore, the moisture absorption and moisture transmission capability of the fiber is closely related to fabric moisture transmission;

(2) Another important way of fabric moisture permeability is that water vapor directly diffuses to the other side through the gap between yarn fibers in the fabric. Therefore, the tight structure and thickness of the fabric are also important factors affecting fabric moisture permeability.

Improvement Method of Fabric Moisture Permeability

(1) It can be changed by changing the parameters of the fabric structure. Such as fabric thickness, warp and weft density, yarn fineness and twist, etc. to improve the moisture permeability of the fabric;

(2) For chemical fiber fabrics, if the fibers can have more microporous structures during the manufacturing process, the moisture permeability can also be improved;

(3) After the fabric is impregnated with ester polymer, it is heated to make it decompose and expand, and to form tiny pores containing hydrophilic base ends in the fabric to increase the moisture permeability;

(4) Moisture permeability is achieved through coating. The coating agent with waterproof and moisture-permeable function is coated on the surface of the fabric, and the microporous structure on the coating or the hydrophilic group in the coating agent interacts with water molecules, and with the help of hydrogen bonds and other intermolecular forces, After absorbing water molecules on the high-humidity side, it is transferred to the low-humidity side;

(5) Moisture permeability is achieved by laminating a waterproof and moisture-permeable membrane. For example, TPU film is the abbreviation of thermoplastic polyurethane, which belongs to non-porous hydrophilic film. The moisture permeability is mainly through the hydrophilic property of the film, relying on the difference of vapor pressure inside and outside the clothes, to transfer the steam from the place with high pressure to the place with low pressure. Thereby the function of moisture permeability is realized.

AVENO machine for testing waterproof and moisture permeability of fabrics：

AG51 Fabric Water-vapor Transmission Tester