Because woolen pants themselves are a “failed” thermal textile.
The core reason is exactly the opposite of everyone’s traditional understanding
It is that the warmth retention of woolen trousers is very poor
Because the yarns of woolen trousers are too thick and intertwined with each other A very large gap will remain
The core of keeping clothes warm is not how thick they are, but how to stay still within the limited thickness. More air, because air is a poor conductor of heat, reducing heat convection and heat conduction is the core of warmth.
Take the down jacket necessary to withstand the harsh winter
Down
Down can store 380 times the volume of its own fiber. The volume of air it stores is 3.8 times that of wool and 5 times that of cotton. This is also the thermal conductivity of down. The reason why the coefficient is so close to air.
The gaps in the fabric of woolen pants are too big, and the breathability is too good to prevent heat convection, so we can only improve the woolen pants as much as possible. The thickness makes up for the shortcomings of large yarn gaps.
As for the thermal underwear we often wear now, the fabric is very tightly woven, and it can be very thin while still achieving a very good thermal insulation effect.
Wool pants need to be worn very thickly to keep warm, which has completely deviated from the current market demand for lightness and warmth.
It is easy for everyone to think of the large gaps in the fabric, but the difference in fiber composition also has a great impact on the warmth retention.
In the past, many woolen pants were hand-knitted by elders using wool balls
So usually there is only one One type of fabric composition, such as cotton, wool, and acrylic are the most common.
However, a single component has many shortcomings. For example, pure acrylic fabrics are prone to static electricity, and wool fabrics are prone to felt shrinkage.
Today’s thermal underwear is not only tightly woven,
the fabric composition is also very particular.
They are generally made of acrylic, polyester, and spandex blended fabrics
Acrylic fiber mainly provides warmth, because The nickname of acrylic fiber is artificial wool. Its fluffy and curly shape can better still the air.
Although viscose fiber is a chemical fiber, it is 50% more hygroscopic than cotton, so it can improve the moisture absorption and breathability of clothing, and at the same time, it can neutralize the stinky problem of acrylic fiber causing static electricity.
Spandex provides elasticity to clothes, which can better cover the body, reduce wind and air leakage in clothes, and further improve the thermal insulation effect.
This kind of thermal underwear with diverse ingredients and tight weaving naturally makes woolen pants obsolete.
Finally, some people may ask
Why haven’t thermal underwear eliminated sweaters?
Because sweaters and woolen pants are not the same category.
You can go out wearing a sweater alone, but it is very abnormal to go out wearing only woolen pants
So wool pants are essentially It is worn internally and is based on warmth retention.
Sweaters are fashionable and can come in a variety of styles, but warmth is secondary, which can be compensated by wearing thermal underwear.
