Judgement of the quality of outdoor sportswear fabrics

Although there are many types of outdoor sports, professional outdoor sports clothing such as assault suits are mainly for alpine sports such as mountaineering and skiing. In addition to the physical abilities and skills of the participants, outdoor sports also require outdoor clothing that can adapt to harsh weather and complex geographic environments to ensure the personal safety of the athletes.

Although there is no essential difference between outdoor sportswear and home clothing, due to the two characteristics of outdoor and sports, the requirements for clothing are relatively strict and demanding: outdoor sports generate high heat and evaporate sweat, which requires good heat dissipation and ventilation performance. It is inevitable to encounter wind, rain, snow and fog in the wild. Clothing must have a certain degree of waterproof performance. Outdoor sports want to reduce the load as much as possible, and the clothing should be as light as possible. Outdoors are windy, cold in the mountains, and have high requirements for wind and warmth. Outdoor washing conditions are limited. High pollution requirements.

　　Climbing and wearing forests for field work, clothing requires good stretch resistance and tear resistance... These performance requirements are very demanding from the perspective of textile technology, and even many indicators conflict with each other. No single natural or chemical fiber can meet these requirements. It can only achieve these functions as much as possible through the composite of multiple fibers and multi-channel chemical finishing.

　　1, warmth retention:

　　Although the warmth retention is closely related to the thickness of the fabric, outdoor sports do not allow clothing to be too heavy, so it must be warm and light to meet the special requirements of outdoor sportswear. The most common method is to add special ceramic powder containing chromium oxide, magnesium oxide, zirconium oxide, etc. to the synthetic fiber spinning solution such as polyester, especially nano-level fine ceramic powder, which can absorb visible light such as sunlight and convert it into Thermal energy can also reflect the far infrared rays emitted by the human body, so it has excellent heat preservation and heat storage performance. Of course, the far-infrared ceramic powder, adhesive and crosslinking agent can also be formulated into finishing agents, and the woven fabric can be coated, and then dried and baked to make the nano ceramic powder adhere to the surface of the fabric and the yarn between. This finishing agent emits far-infrared rays with a wavelength of 8 to 14 μm, and also has health-care functions such as antibacterial, deodorant, and blood circulation promotion.

In addition, according to the principle of bionics and referring to the structure of polar bear hair, the polyester fiber is made into a porous hollow shape inside, so that the fiber contains a lot of airless air, and the outside is made into a spiral curl shape to maintain the bulkiness, which can guarantee the light texture. Play a good thermal insulation effect. Of course, making clothes and even fabrics into double or even triple layers to increase the number of air-impermeable layers is also one of the most traditional measures to keep warm.

　　2, waterproof and moisture permeability:

　　 Sports will emit a lot of sweat, and it is inevitable to encounter wind and rain outdoors. This is a contradiction in itself: it is necessary to prevent rain and snow from being soaked, but also to discharge the sweat from the body in time. Fortunately, the human body emits water vapor in a single-molecule state, while rain and snow are liquid water droplets in an aggregated state. Their sizes are very different. In addition, liquid water has a characteristic called surface tension, which is the characteristic of gathering its own volume. The water we see on the lotus leaf is a granular water drop instead of a flat water stain. This is Because there is a layer of waxy hairy tissue on the surface of the lotus leaf, water droplets cannot diffuse and penetrate this layer of waxy hair due to surface tension. If you dissolve a drop of detergent or washing powder into the water droplets, since the detergent can greatly reduce the surface tension of the liquid, the water droplets will immediately disintegrate and spread on the lotus leaf. Waterproof and moisture-permeable clothing is to use the surface tension characteristics of water to coat the fabric with a layer of PTFE (the same chemical composition as the "King of Corrosion Resistant Fiber" PTFE, but the physical structure is different) to enhance the surface tension of the fabric The chemical coating makes the water droplets as tight as possible without spreading and infiltrating the surface of the fabric, and thus cannot penetrate the pores in the fabric. At the same time, the coating is porous, and the water vapor in the monomolecular state can be smoothly transmitted to the surface of the fabric through the capillary channels between the fibers.

After a large amount of exercise, if you stop to rest in the wild, it is possible that water droplets will form on the inner layer of the clothes because the outside temperature is low and the sweat cannot escape in time, which makes people feel very uncomfortable. This is the so-called " Condensation" phenomenon. There is a special moisture permeability finishing process called "low condensation", which uses polyurethane (PU) and hydrophilic nano ceramic powder to coat the fabric, which can be absorbed when the body evaporates a lot of sweat More sweat vapor, so as to avoid the phenomenon that the water vapor inside the clothes exceeds the saturated vapor pressure and turns into water droplets.

　　 In addition to finding ways from fibers and coatings, the fabric structure can also absorb moisture as much as possible. For example, the use of a double-layer structure, the inner layer of the body is made of hydrophobic fibers, and the outer layer is made of hydrophilic fibers, so that sweat can rely on capillary action to transfer from the skin to the inner fibers, and the outer layer is hydrophilic. The binding force between the fiber and the water molecule is stronger than that of the inner hydrophobic fiber, and the water molecules are transferred from the inner layer to the outer layer of the fabric again, and finally distributed to the atmosphere.

　　3, antibacterial and deodorant:

　　Due to the characteristics of exercise, sweat and sebaceous glands secrete a lot. In outdoor conditions, it is impossible to change clothes frequently. Under suitable temperature and humidity, microorganisms will multiply, causing undecent odors and itching. Therefore, regular outdoor sportswear is chemically finished with antibacterial and deodorant. The finishing method is generally to fix the bactericidal organic quaternary amine type, imidazoline type surfactant or heavy metal ions such as silver and copper on the fiber through resin and cross-linking agent to make it have a certain degree of washing resistance. Of course, an important principle for choosing a fungicide must be non-toxic or low-toxic, otherwise it will be the last resort. In recent years, Japan has made a lot of exploration in the research of natural antibacterial finishing agents. For example, the use of bactericidal aromatic oil extracts such as aloe, mugwort, eucalyptus, rose, etc., is coated in porous organic microcapsules or porous The ceramic powder adheres to the fabric and is cross-linked and fixed by resin, and the fungicide is slowly released through mechanical action such as friction and backlog to achieve the purpose of durable antibacterial finishing. This type of natural antibacterial agent is not only non-toxic and harmless, but also has a certain health function, which should be the development direction of antibacterial finishing. However, due to the limited means of fixing the antibacterial agent, the washing resistance of the antibacterial agent is not good enough, and the antibacterial performance decreases a little after washing, and generally disappears completely after dozens of times.

The American Dow Corning AEGIS anti-mold and antibacterial agent uses molecular bonding to evenly distribute the eighteen long carbon chains on the surface of the fabric, and combines them with the fabric fibers, and then relies on physical action to sterilize, unlike other sterilization through chemical action , In order to achieve permanent antibacterial effect.

　　4, anti-fouling and easy decontamination:

　　Outdoor sports often walk through the muddy and humid mountains and forests. It is inevitable that the clothes will get dirty. This requires the appearance of the clothes to be as easy as possible not to be stained by stains, and once they are stained, they must be easy to wash and remove. Changing the surface properties of the fiber greatly improves the surface tension of the fabric, making it difficult for oil stains and other stains to penetrate into the fabric. Slight stains can be removed by wiping with a damp cloth, and heavier stains are also easy to clean. The anti-fouling finishing can not only prevent oil pollution, but also has the performance of waterproof and moisture permeability. It is generally called "three-proof finishing" (water repellent, oil repellent, and anti-fouling), which is a more practical and effective advanced chemical finishing method. It is often used on the outer layer of clothing and the fabric finishing of backpacks, shoes and tents.

　　 5. Anti-static and anti-radiation finishing:

Mountain climbing is the core content of outdoor sports. In addition to the original dense forest, the high and high altitude areas above 3000 meters above sea level are generally dry due to low air pressure and easy moisture volatilization. Outdoor clothing is basically made of chemical fiber fabrics, so static electricity The problem is more prominent. The hazards of static electricity are generally manifested as clothes fuzzing and pilling, dust and dirt, electric shock and sticky feeling close to the skin, etc. If you carry sophisticated electronic instruments such as electronic compasses, altitude meters, GPS navigators, etc., they may be interfered by static electricity in your clothes and cause errors, which may bring serious consequences.

　　 Any object rubbing against each other may generate static electricity, but only dry insulating objects can accumulate static electricity and cause harm. Therefore, the best antistatic fabric is of course woven from natural fibers, but as mentioned earlier, pure natural fibers are difficult to meet the special requirements of outdoor sports, and even natural fibers will suffer from lack of water molecules in very dry environments. And generate static electricity. There are two main ways of antistatic finishing of fabrics: one is to simply weave metal wires into the fabric to make a conductive fabric (also electromagnetic wave shielding fabric and anti-radiation fabric), and conduct static electricity generated by friction to the outside world in time. . But this kind of fabric is not suitable for sportswear, mainly because of its poor softness and insufficient comfort. Another method is to use block polyethers, polyacrylates and other antistatic agents with hygroscopic effect to coat the surface of the fabric with a chemical film that can absorb water molecules to form a continuous conductive water film on the surface of the fabric. Dissipate static electricity.

　　 Because the atmosphere is relatively thin in high altitude areas, the blocking and filtering effect of ultraviolet rays is greatly reduced, and the intensity of ultraviolet rays is much higher than that in low altitude areas. Ultraviolet rays can effectively promote the production of vitamins and have a bactericidal effect, but excessively strong radiation can cause damage to human skin. The penetration of ultraviolet rays is very strong, and general fiber fabrics cannot completely shield its radiation. Resins are used to combine nano-level inorganic titanium dioxide (TiO2), nano-zinc oxide (ZnO) and other ultraviolet shielding agents and organic salicylic acid, cyanoacrylate, benzophenone, benzotriazole and other ultraviolet absorbers. The method of cross-linking fixed on the fabric can play a certain role in radiation protection.