[Characteristics of outdoor clothing]What is outdoor clothing and what are the characteristics of outdoor clothing
What is outdoor clothing
The outdoor environment is complex and changeable. In order to resist the harm of the harsh environment to the human body, protect the body heat from being lost, and quickly discharge the sweat generated during exercise, in mountaineering, rock climbing and other outdoor sports When you do, you should dress in layers.
The so-called outdoor layered dress refers to wearing clothes of different materials in outdoor sports to adapt to the impact of various weather changes in the wild on the human body, such as jacket
s, Fleece underwear, thermal underwear, sun protection underwear, quick-drying underwear, etc.
What are the characteristics of outdoor clothing
Insulation
Although insulation is closely related to fabric thickness Related, but outdoor sports do not allow clothing that is too heavy, so it must be both warm and light to meet the special requirements of outdoor sports clothing. The most common method is to add special ceramic powders containing chromium oxide, magnesium oxide, zirconia and other special ceramic powders, especially nano-scale fine ceramic powders, into the spinning solution of synthetic fibers such as polyester, which can absorb visible light such as sunlight and convert it into It can also reflect the far infrared rays emitted by the human body itself, so it has excellent thermal insulation and heat storage performance.
Moisture permeability
Waterproof and breathable garments use the surface tension properties of water to coat fabrics. A chemical coating of PTFE (which has the same chemical composition as the ‘King of Corrosion Resistant Fiber’ PTFE but different physical structure) to enhance the surface tension of the fabric is covered with a chemical coating to make the water droplets tighten as much as possible without spreading and infiltrating. the surface of the fabric so that it cannot penetrate through the pores in the fabric. At the same time, the coating is porous, and the water vapor in the single-molecule state can be smoothly emitted to the surface of the fabric through the capillary pores between the fibers.
If you stop and rest in the wild after a large amount of exercise, it is possible that water droplets will form on the inner layer of the clothes because of the low outside temperature and the inability of sweat to escape in time, which will make people feel uncomfortable. A very uncomfortable feeling, this is the so-called ‘condensation’ phenomenon. There is a special moisture-permeable finishing process called ‘low condensation’, which uses polyurethane (PU) and hydrophilic nano-ceramic powder to coat the fabric, which can absorb a lot of sweat when the body evaporates. More sweat vapor, thus avoiding the phenomenon that the water vapor inside the clothes exceeds the saturated vapor pressure and turns into water droplets.
In addition to finding solutions from fibers and coatings, the fabric structure can also try to absorb moisture and sweat. For example, a double-layer structure is adopted, the inner layer of the body is made of hydrophobic fibers, and the outer layer is made of hydrophilic fibers, so that sweat can be transferred from the skin to the inner layer fibers by capillary action, and then due to the hydrophilicity of the outer layer The binding force between fibers and water molecules is stronger than that of the inner hydrophobic fibers, and the water molecules are again transferred from the inner layer of the fabric to the outer layer, and finally released into the atmosphere.
Water resistance
The primary function provided by outdoor clothing is water resistance, and most traditional fabrics have a waterproof finish that is Coatings or films, and later water repellants with fluorochemical or silicone finishes. The effect of waterproofing can be expressed in terms of water resistance and surface moisture resistance.
gb/t4744?C1997 ‘Hydrostatic Pressure Test for Water Resistance of Textile Fabrics’ uses the hydrostatic pressure on the fabric to represent the resistance that water encounters through the fabric, that is, in the Under standard atmospheric conditions, one side of the sample is subjected to a continuously rising water pressure until water seeps in three places, and the pressure at this time is recorded, expressed in kpa or cmh2o, the larger the value, the better the waterproof performance.
Breathability
A good piece of outdoor clothing is not only rainproof but also breathable. Its air permeability is determined by the microporous structure of the film, allowing gaseous water molecules to escape and 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 the airflow passes vertically through the sample under the specified test area, pressure drop and time conditions. The unit is mm/s or m/s. The larger the value, the better the air permeability. The recommended test area in gb/t5453-1997 ‘Determination of the Air Permeability of Textile Fabrics’ is 20cm2, and 5cm2, 50cm2 or 100cm2 can also be used; the pressure drop for fabrics is 100pa, and the pressure drop for industrial fabrics is 200pa. Applicable, 50pa or 200pa can be selected after negotiation by relevant parties.
Quick-drying
Moisture-absorbing and quick-drying is to quickly absorb the sweat produced by the body and discharge it as far as possible. The outer layer evaporates as quickly as possible to keep the body as dry as possible. GB/T21655.1-2008 ‘Evaluation of the moisture absorption and quick drying of textiles – Part 1: Single combination test method’ is used to characterize the absorption capacity of fabrics for liquid sweat by the water absorption rate, drip diffusion time and wicking height of fabrics; The moisture evaporation rate and moisture permeability in the specified air state characterize the quick-drying properties of the fabric in the state of liquid sweat. This standard makes specific technical requirements for knitted and woven products that are expressly classified as hygroscopic and quick-drying products. GB/t21655.2-2008 ‘Evaluation of the hygroscopic and quick-drying properties of textiles Part 2: Dynamic moisture transfer method’ stipulates the test method. It is: the fabric sample is placed horizontally, and after the liquid water contacts its immersion surface, the liquid water will diffuse along the immersion surface of the fabric, and transfer from the immersion surface of the fabric to the permeable surface, and at the same time diffuse on the permeable surface of the fabric. is a function of time. When the test liquid is dropped on the immersed surface of the sample, the sensor in close contact with the sample is used to measure the dynamic transfer of liquid water, and a series of performance indicators are calculated to evaluate the performance of textiles such as moisture absorption, quick drying and perspiration.
Antistatic
Outdoor clothing is basically made of chemical fiber fabrics, when the outdoor environment is relatively dry At this time, there will be static problems, which are manifested in that the clothes are prone to pilling, easily contaminated with dust and dirt, and close to the skin to generate electrostatic adsorption. If you carry precision electronic instruments such as electronic compass, altitude meter, gps navigator, etc., it may be disturbed by the static electricity of clothing and cause errors, resulting in serious consequences.
Comparing the existing national standards and industry standards, the evaluation indicators of each method are different, and the results obtained by using different test methods are not comparable. The surface charge density method can better simulate the electrification process of outdoor clothing when it is actually worn, and it is a suitable method to test the antistatic performance of outdoor clothing.
UV resistance
The evaluation parameter of textile UV radiation protection adopts the value of UV protection factor upf, It expresses the ratio of the average effect of UV radiation calculated when the skin is unprotected to the average effect of UV radiation calculated when the skin is protected by a fabric. GB/T18830-2009 ‘Evaluation of Anti-UV Performance of Textiles’ stipulates the test method, representation, evaluation and identification of protection level of textiles for the anti-ultraviolet performance of textiles. , collect the total spectral transmission rays, determine the total spectral transmittance t(??), and calculate the UV protection factor upf value of the sample. The specimen can be illuminated with a parallel beam and all transmitted light can be collected with an integrating sphere; the specimen can also be illuminated with a light hemisphere to collect parallel transmitted light. In actual operation, the detection instrument can automatically calculate the upf value and t(??) of the sample. When the upf value of the sample is greater than 50, it is expressed as ‘upf > 50’. According to this standard, when the upf of the sample is greater than 40, and the t(uva)av is less than 5%, it can be called ‘UV protection product’.