Basic Knowledge Of Heating Underwear

With the first snowfall in Beijing this winter, the temperature dropped suddenly, and all kinds of warm clothing have also become a hot spot of consumption. In addition to the usual thermal underwear, underwear, which claims to be able to generate heat, is becoming popular among consumers. Is it true that heated underwear can be heated as it is publicizing? What is the raw material of the heated underwear? What is the difference between the underwear and the ordinary underwear?

　 　 Thermal underwear The main raw material is hygroscopic polycondensation fiber.

Reporters visited several shopping malls and supermarkets in Beijing and found that many businesses were selling hot underwear. The main trademarks were polyester and acrylic, and a small amount of viscose and spandex. Reporters found that many hot underwear claims that the fiber itself can absorb the steam evaporated by the body and convert it into heat, and the material itself will become warmer.

The concept of "hot underwear" was born in Japan. The first heating underwear is to improve the chemical fiber material, mainly based on daily chemical fiber. Because fiber moisture absorption and heating function is better. In fact, there are many ways to generate heat, including heating after moisture absorption, utilizing electric energy to generate heat and converting solar energy into heat energy. At present, the common underwear in the market is the principle of moisture absorption and heating to achieve the effect of keeping warm. Wang Zhi, director of the China knitted Technical Committee, told reporters that in fact, all fibers have the effect of heating, but the degree of heat generated by different fibers is different from that of calorific value. From the perspective of heating effect, natural materials such as wool, viscose and so on, generally have larger moisture absorption capacity, and their heating capacity is larger than ordinary fibers. The study found that in the contrast of integral heat (i.e. the heat produced by 1 grams of dry fiber after fully absorbing water), the calorific value of wool reached 26.9 cards, which is more suitable for heating underwear materials.

　　 Heating fiber First used by mountaineers.

Beijing clothing Gong Yan, a professor at the College of materials science and engineering, said that the raw material of heating underwear is a special kind of fiber material, which is expensive. Generally, the heating underwear is made of a small amount of heating fiber and other fibers. Most of them contain viscose fiber, modal fiber, bamboo charcoal polyester fiber or regenerated fiber. This fiber material was first used by mountaineers, and later extended to ordinary consumption, mainly for underwear production. For example, "salad" is actually added ultrafine particles of ceramic in chemical fiber acrylic fiber, so that it has the effect of heating. Modal fiber is a material with high moisture regain, which can be converted into heat after absorbing water.

"In recent years, a new type of fiber, which can generate heat itself, has been developed as a material for thermal underwear. The main way to make warm and hot fiber is to add special chemical components in the fiber, so that it can produce chemical reaction under certain conditions and generate heat. For example: Thermotron fiber solar thermal storage insulation fiber, Outlast air conditioning fiber phase change thermal storage fiber, Eks moisture absorption heating fiber, Textcare nano bamboo charcoal fiber and Ceramino infrared thermal insulation fiber, etc., Tianjin City Spin Yu Kun, senior engineer of Fiber Inspection Institute, told reporters that at present, underwear manufacturers in China mainly use moisture absorption and heating fibers as raw materials, and develop knitted fabrics through different proportions and processes, changing the form of traditional thermal fabrics to be thick and bloated, so that thermal fabrics can be characterized by light, thin, soft and warm.

　　 Heating underwear can not be replaced Cotton-padded clothes

Lee has just bought two hot underwear, but the so-called warming feeling is not obvious. In this regard, Wang Zhi explained that after the human body is wearing hot underwear, the hydrophilic groups in the fiber molecules combine with the moisture released by the human body, which will reduce the movement of human body water, thereby reducing the heat loss of human body. The kinetic energy can be transformed into 2 degrees -4 degrees centigrade, but at the same time, it should be noted that even if the real underwear is heated, the temperature raised is limited, so the public can not use hot underwear to replace cotton coat.

Buy reminder

Recognize the "yellow bottom black character" hot underwear logo

In December 2010, China implemented the industry standard of moisture absorption and thermal underwear, and the special standard for heating underwear was also tested. According to the industry standard, judging whether underwear meets the standards of thermal underwear, there are two main dimensions: first, the minimum peak temperature should be greater than 3 degrees Celsius; in addition, taking into account the heat dissipation and other factors, the average temperature increase in 30 minutes is greater than 2 degrees Celsius, which is the lowest threshold.

Gong cautioned that the publicity of the underwear on the market is diverse and true and false. It is difficult to define the authenticity of the underwear in terms of product performance. The environmental protection standards research committee of China is also developing the more comprehensive standards of functional clothing, which is helpful to the quality specification of different categories of functional clothing. When purchasing hot underwear, consumers should check whether they are putting up the logo of the hot underwear with a yellow bottom in the box. The logo indicates the name of the heating fiber, the heating effect and the addition ratio. In addition, the best way to buy hot underwear is to go to regular shopping malls and supermarkets.

　　 Common underwear types in the market

　　 Hygroscopic heating

The mechanism of fiber absorption and heating is that when the fiber absorbs moisture, the hydrophilic groups in the fiber molecules combine with the water molecules, and the kinetic energy of the water molecules decreases, and at the same time, the heat is released to heat. Generally, the moisture absorption and heating properties have a great relationship with moisture regain. The moisture regain of the fibers is high, and the moisture absorption and heating performance are good. The moisture regain rate is small, and the moisture absorption and heating performance is poor. For example, wool and modal fiber have good moisture absorption and heating effect; the moisture absorption and heating effect of ordinary acrylic and polyester fibers are poor.

　　 Solar energy storage

By adding special substances into the fiber, the solar energy is converted into thermal energy and emitted far infrared rays with a longer wavelength to warm the interior of the garment.

　　 Phase change thermal storage

By adding thermal sensitive phase change material in the fiber, it can absorb, store and release heat in the form of latent heat. In the process of temperature change, solid liquid can be transformed into each other, so as to achieve the effect of heat absorption and heating.