In recent years, a self-heating underwear that claims to be able to "produce heat out of thin air" has quickly made its debut on major platforms, attracting the attention of netizens, but this seemingly unregulated publicity is IQ tax or real heat-producing black technology?

In recent years, a self-heating underwear that claims to be able to "produce heat out of thin air" has quickly made its debut on major platforms, attracting the attention of netizens, but this seemingly unregulated publicity is IQ tax or real heat-producing black technology? Come on, follow the passers-by and listen to the passers-by.

"Self-heating underwear"

Every winter, all kinds of warm products appear in front of the public. In addition to popular daily warm products such as electric blankets and hand warmers, warm underwear has undoubtedly become the most popular clothing among consumers. However, in order to keep warmer, conventional thermal underwear is generally thicker and more bulky to wear. In the face of the cold weather of in the northern region of , you have to keep warm with "three layers inside and three layers outside".

Therefore, the "self-heating underwear" that can be called the black technology in the underwear industry was launched and has gradually occupied major platforms. According to merchants, "self-heating underwear" is a kind of self-heating and uses Defence material, which can maintain a constant temperature of 37℃. This underwear is light and thin, meeting the needs of many women for thin and warmth.

A business introduction picture

Since the market for "self-heating clothes" was developed, the fabrics were varied, such as wool, silk, viscose fiber, acrylic , etc., and the prices ranged from dozens of yuan to hundreds of yuan. However, the most popular one is a kind of "Developer" that claims to be "German black technology". German velvet is not the name of a material, but because this fabric was invented by German Bayer company , it is called "Developer".

Defeng is actually a blended chemical fiber fabric . The ingredients are mainly acrylic, doped with spandex and polyester . There is a layer of chemical substance on the surface of the structure. It is understood that the fluffy fabric of Deflorum is 10% higher than other fibers and is 17% higher than cotton. So can it heat itself?

Can "self-heating clothes" become hot on their own?

In order to prove whether the effect of "self-heating underwear" is true, a reporter from CCTV Finance's " First Time " column video specially conducted actual testing on this. They purchased two sets of hot-selling "self-heating underwear" from different brands online, with a price of around 100 yuan. After the goods arrived, the reporter brought the experimental target to the National Textile Production Quality Inspection Center to check whether they comply with relevant national standards.

According to relevant standards, the staff completed the test of the experimental target in an environment with a temperature of 20 degrees and a humidity of 90%. The results showed that the peak temperature increase of these two heating jackets reached 9.5 degrees and 7.6 degrees respectively, which has greatly exceeded the original standard 4 degrees. However, in the average heating value within 30 minutes, only one self-heating coat can barely meet the standard. Obviously, self-heating clothes can indeed heat up briefly, but they do not continuously provide heat energy.

In this regard, Wang Baojun, director of the National Textile Products Quality Inspection Center, also said that in fact, the " self-heating " introduced on the market does not cause heat on its own, but "hygroscopic heat". Most fibers themselves have the function of absorbing hygroscopic heat, but the degree is different.

"Self-heating underwear" actually circulates in the process of absorbing moisture, releasing heat, releasing heat, and absorbing heat. When the moisture absorption reaches saturation, the moisture will no longer be absorbed, and the heat dissipation will be gone. When the temperature of the external environment is relatively low, after completing a process of absorbing heat and dissipating moisture, you will gradually feel cold. In other words, "self-heating discussion" is actually just a stolen change of concepts, not a person who heats up, but absorbs heat from the body.

Whether a piece of clothing is warm depends mainly on the fluffyness and thickness. In addition to the "Defeng self-heating underwear", there is also a kind of heating underwear that claims to have added graphene components. Graphene is a nanomaterial and is currently the material with the highest thermal conductivity, with a thermal conductivity of up to 5,300 W/(m·K), but it is very expensive. If the lower price claims to be added to graphene, the effect is almost negligible.

Currently, there are three types of "self-heating" products on the market: hygroscopic heating, far-infrared heating, electric heating, etc. These three are actually not products that will heat themselves. Self-heating requires energy sources and heat will not be generated out of thin air.So in other words, "self-heating" is actually not a black technology, but a gimmick used by businesses for publicity. We should also pay attention when choosing and not blindly follow the trend.

Safety indicators of heating underwear, "thin and warm cannot have both"! The fabrics of the two "self-heating underwear" tested by

are both "moisture-absorbing and heating fibers". You must know that no matter what kind of natural fiber they are, they all have certain moisture-absorbing and heating properties, among which the thick wool fiber is the most significant. The moisture absorption rate is high, and the fiber does have a certain degree of heating effect, but this is only suitable for short-term temperature rise. Once the dressing and humidity on the surface of the fabric reach saturation, subsequent insulation can only rely on the inherent thermostatic performance of the human body.

In the field of thermal underwear, the country has also formulated relevant industry standards. The industry standard for "Knitted Thermal Underwear" is FZ/T 73022-2004, and the thermal insulation rate of the product must not be less than 30%; the implementation standard for " Hygroscopic and Heating Knitted Underwear " is FZ/T 73036-2010, the heating index requirements for this type of product are: the "maximum temperature rise value" is not less than 4℃; and the average temperature rise value within 30 minutes is not less than 3℃."

If it does not meet the standard, its heating performance will obviously be greatly reduced. If the fabric is made of inferior raw materials , and may cause other damage to the human body. Therefore, when choosing thermal underwear, be sure to pay attention to the standard number, and be sure to choose clothes that meet the national standards. Generally, those that meet the standards and are warm are not too thin, so remember that thinness and warmth cannot be achieved at the same time.

Well, that’s it for today. Follow the passers-by and see you in the next issue.