Is self heating underwear really a magic weapon against cold? The test results are surprising! Heating up fast, but

How to keep out the cold when the cold wave comes? I’m sure someone’s going to talk about wearing autumn pants. When it comes to autumn pants, recently self heating underwear, which is known as high-tech “cold proof artifact”, has become the most popular fashion item. In the major e-commerce platforms, the prices of all kinds of self heating underwear range from tens to hundreds of yuan, and the sales volume often exceeds 10000 yuan. The product performance publicity such as “the highest temperature can reach 8 ℃” and “the average heating rate in 30 minutes is 3.1 ℃” is even more eye-catching. Is a underwear really so magical? < / P > < p > consumer: I think if the thickness is not enough, it’s still not warm enough. If that kind of hot, thin underwear can top a few, I don’t think so. < / P > < p > the reporter bought two sets of hot-selling self heating underwear from the Internet, and the price is about 100 yuan. It is noted on the commodity details page that the fabric of the two underwear is “moisture absorption and heating fiber”. The reporter took them to the national textile products quality inspection center, and the staff tested them according to the relevant national standards. < p > < p > reporter Lu Nian: behind me is a moisture absorption and heating instrument. According to the national standard, we set the temperature at 20 ℃ and the humidity at 90%, and then put the sample into such an environmental box to test the effect of moisture absorption and heating. < p > < p > > the samples were dried in a wet dryer for more than four hours, and then discharged into the dryer for more than one hour. < / P > < p > Zhang Rui, engineer of national textile product quality supervision and inspection center: the dryer is a device to ensure that the sample no longer absorbs moisture from the outside. The particles under the dryer are color changing silica gel, which is used to ensure the drying environment inside the container. After we take the dried sample from the oven, it will be put into a glass container, and then sent to the hygroscopic and heating environment box through the glass container. < / P > < p > insert the prepared sample on the three metal sensors of the moisture absorption and heating environment box, and the detection can be started. According to the relevant national standards, the test is carried out at 20 ℃ and 90% humidity. The test results show that the maximum temperature rise values of the two self heating underwear are 9.5 ℃ and 7.6 ℃ respectively, far exceeding the standard requirement of 4 ℃. The average temperature rise value within 30 minutes is 3 ℃ or more, one of the two products is 3.8 ℃, just reaching the standard, while the other is 2.8 ℃, not reaching the standard. < / P > < p > Zhang Ting, researcher of Institute of Engineering Thermophysics, Chinese Academy of Sciences: the evaluation standard of hygroscopic heating fiber needs to be further improved, because we can’t reach 90% humidity in real life. < / P > < p > in addition to the detection standard needs to be improved, it can be seen from the experimental data chart that the temperature of the two self heating underwear reached the peak value about 5 minutes after the detection, and then the temperature began to decline. Within 30 minutes, the temperature of both products experienced a change from low to high and then to low. Experts pointed out that this is because the humidity of the test environment has been maintained at 90%. When the moisture absorption of the self heating underwear fiber is saturated, it will stop moisture absorption and heating, and turn to absorb human body heat and release humidity. In other words, the temperature of self heating underwear rises and falls fast. < / P > < p > Wang Baojun, director of national quality inspection center of textile products: self heating underwear will absorb moisture and heat in four or five minutes or five or six minutes, and then the temperature will drop rapidly. When it reaches 20 to 30 minutes, the fabric will basically no longer generate heat. Let’s say its temperature has been raised by 2 ℃, 3 ℃ or a few degrees Celsius, that is, for a while, and then it will return to its original state. I don’t think self heating underwear can keep warm at all. < / P > < p > Wang Baojun, director of the national textile products quality inspection center: the same weight, for example, 500 grams, some clothes may be 3 mm thick, some may be 10 mm thick. The 10 mm thick one is warmer than the 3 mm thick one because it contains more air. Air acts as an insulating layer in clothing. So the same weight, the more fluffy the more warm. Under the same fluffy condition, the thicker the warmer. These are the two basic principles. Iqoo5 series debut strength interpretation of “120 super full mark flagship”