Is the "black technology" to keep warm reliable?
□ All clothing fibers will absorb the moisture evaporated from the air or human body when they enter a relatively humid environment from a dry environment. During the moisture absorption process, heat energy will be generated. The more moisture absorbed, the more heat will be released.
Tests have shown that self-heating underwear has a certain improvement in heating effect compared with ordinary cotton underwear, but the difference in temperature rise is not high.
□ Consumers should carefully check product labels when purchasing "black technology" thermal clothing, and give priority to products with complete three standards, detailed content, manufacturer verification, and quality inspection.
Recently, as the temperature has dropped sharply, the sales of thermal clothing have entered a peak period. Many thermal clothing products with "self-heating", "far-infrared" and "graphene" as selling points are selling well.
Compared with natural fibers, are warm clothes equipped with "black technology" reliable?
It is reported that the National Textile Products Quality Supervision and Inspection Center has conducted professional testing on three different brands of hygroscopic and heating underwear purchased from physical stores and online stores.
After the inspectors completely dry the hygroscopic and heating underwear, they put them into a test box with a temperature of 20°C and a humidity of 90% for testing for 30 minutes.
The results showed that the three samples all generated heat after absorbing moisture, and the degree of temperature rise was basically the same. The highest temperature rise was about 7°C, and the average temperature rise within 30 minutes was about 2.7°C.
Under the same conditions, inspectors tested traditional cotton underwear.
The results showed that the maximum temperature rise of pure cotton underwear was 5.9°C, and the average temperature rise within 30 minutes was 2.0°C.
It can be seen that the heating effect of self-heating underwear is better than that of ordinary cotton underwear, but the difference in temperature rise is not high.
Wang Baojun, director of the National Textile Products Quality Supervision and Inspection Center, said that all clothing fibers from a dry environment into a relatively humid environment will absorb moisture evaporated from the air or the human body, and heat energy will be generated during the moisture absorption process. The more moisture absorbed, the more heat released.
Some self-heating clothes add some other substances to ordinary fibers to increase the hydrophilic groups in the fibers and increase the moisture absorption, thereby improving the heating effect.
The laboratory of the National Textile Products Quality Supervision and Inspection Center has also tested the heating effect of far-infrared heating underwear.
The results showed that the clothes did emit far-infrared rays, which also raised the temperature, with an average temperature rise of 1.6°C, but compared with other moisture-absorbing and heating underwear, the temperature rise was not significant.
Some people in the industry pointed out that the far-infrared heating underwear made of ceramic powder, graphene and other materials added to the fiber material can make the clothes emit a certain amount of far-infrared rays, and form resonance with water molecules in human cells to produce thermal effects and promote subcutaneous heating. blood circulation, which makes the body feel warm.
However, since the fibers of the clothing are very thin, the amount of added substances should not be too much, otherwise the elasticity and strength of the fibers will be affected.
Liu Li, a professor at the Beijing Institute of Fashion Technology, believes that in recent years, there have been many types of thermal clothing products with "self-heating", "far-infrared" and "graphene" as selling points, but the new products still lack the necessary industry standards.
In the long run, in order to better meet consumer demand, "black technology" thermal clothing needs continuous breakthroughs in product innovation, a unified standard in standard formulation, and more trust in brand building.
Faced with a dazzling array of "black technology" thermal clothing, how should consumers choose?
The relevant technical director of Testar (Beijing) Textile Inspection Co., Ltd., which specializes in textile testing and certification, told reporters that the materials of traditional thermal underwear chemical fiber fabrics include polyester, acrylic fiber, viscose, nylon and other fibers, and they are often used in different ratios. Occurs in fabric components.
The biggest feature of acrylic fiber is that it has a natural curly and fluffy structure like wool. The fabric made of it can store a lot of air and prevent heat loss. Although it is warm enough, it does not absorb moisture; viscose is breathable but not warm enough; Wet function, while improving the strength of the fabric; nylon can effectively improve the comfort of next-to-body clothing.
In production, manufacturers generally use various fibers through fabric design, scientific blending, and learning from each other to better meet the functional requirements of thermal clothing products.
"According to the needs of the scene, the most suitable one is the best." Lu Zhenxing, director of the technology research and development center of Jinpai Warp Knitting Technology Co., Ltd., suggested that in the cold winter outdoors, if you want to keep your clothes warm to the greatest extent, it is best to wear "sandwich" clothes The method is to lock the body heat tightly through the three links of windproof, warm keeping and moisture absorption.
The outermost layer is the windproof layer, which is usually made of stiff and dense materials to prevent the cold wind from directly invading the body surface and preventing the heat from being taken away from the human body; High-quality materials play a role in storing heat; thermal underwear focuses on breathable and moisture-wicking, while considering the use of warm-keeping concept materials.
The core strength of clothing to keep warm is in the middle insulation layer and the outer windproof layer.
Experts suggest that consumers should not blindly follow the trend. When purchasing warm clothing with "self-heating", "far-infrared" and "graphene" as selling points, they should carefully check the product label, and give priority to choosing products with complete three standards, detailed content, manufacturer verification, Products that have passed the quality inspection.
Xi Ping