The secret behind “cool fabric”: Is it technology or just a gimmick?

What is cool fabric? Cool fabric is actually a kind of fabric that quickly loses heat from the skin surface and instantly drops the temperature when the skin comes into contact with it, thus forming a cool feeling. Cool fabrics generally need to modify the fiber raw materials or perform post-processing on the fabrics to make the fabrics have the functions of rapidly diffusing body heat, accelerating perspiration and cooling. In the market, cool fabrics are widely used in various summer clothing or bedding, such as T-shirts, pants, sunscreen clothing, etc. Composed of cool fibers or after cool finishing, textiles have good thermal conductivity and moisture absorption and quick drying properties. They can quickly absorb and evaporate sweat on the skin surface, quickly take away the heat from the body surface, thereby achieving a cooling effect and keeping the skin dry and comfortable. Cool fabric test standard Can cool fabrics really make the wearer feel cool? How to judge? The national standard GB/T 35263-2017 "Testing and evaluating the instantaneous cool performance of textiles in contact" has a clear test method. This standard stipulates the test and evaluation methods for the instantaneous cool performance of textiles in contact with the skin, which is applicable to all kinds of fabrics and their products. The test principle is to contact the sample with a heat detection plate whose temperature is higher than that of the sample under the specified test environment conditions, measure the change of the temperature of the heat detection plate over time, and calculate its contact coolness coefficient (qmax), thereby characterizing the instantaneous coolness of the sample. The contact coolness coefficient qmax refers to the maximum value of the heat flux density during the heat transfer process after the heat detection plate with a temperature higher than the specified temperature difference of the sample is contacted with the sample at a certain pressure. The larger the qmax value, the stronger the coolness felt by the skin, and the smaller the value, the weaker the coolness felt by the skin. In addition to the test methods, FZ/T 73067-2020 "Contact Cool Knitted Clothing" and FZ/T 62042-2020 "Cool Fabric Bedding" also have clear provisions on the product standards of cool fabrics. These standards have detailed requirements on the fiber composition, safety performance, physical properties, coolness performance, etc. of the fabric to ensure that the quality and performance of cool fabric products meet market demand. "Ice silk" is just a product name. In addition to the cool fabrics that are popular in the market, another kind of ice silk fabric is also in the limelight. What kind of fabric is ice silk that feels cool just by hearing the name? In fact, ice silk can only be regarded as a product name, because there are currently no relevant national standards and textile industry standards to clearly define the concept of "ice silk". The ingredients of ice silk clothing sold on the market mainly include: viscose fiber, polyester fiber, nylon, etc. Tips for purchasing cool fabrics If you want to buy genuine cool fabrics, you must first go through formal channels. It is recommended to choose well-known brands. In addition, pay special attention to the tag information of the product, and don't completely Don't just believe the merchants' propaganda, but check whether the relevant standards are marked on the label. If you buy it offline, it is recommended to touch the surface of the fabric to see if it is smooth and flat. Generally speaking, the cool feeling brought by fabrics with smooth and flat surfaces will be more obvious at the moment of contact. Finally, it should be reminded that some cool fabrics are achieved by adding finishing agents or adding trace amounts of jade, mica powder, etc. to the fiber materials to achieve "coolness". Therefore, consumers can smell the odor when purchasing. If there is a pungent odor, it is best not to buy it. In addition, the cooling function of cool fabrics with finishing agents added will gradually weaken with the increase in the number of washes.