One third of one's life is spent in bed. Holding a comfortable quilt and having a good sleep, which was originally the basic need of the emperor and the common people, has become the extravagant hope of our "fast food era". The related duvet has become the favorite of sleepers. Especially in developed countries such as Japan, Europe and the United States, the popularity of duvet has reached more than 80%. In recent years, The popularity of duvets in China is rising rapidly. So why do consumers love down so much?
First, let's start with the basic principle of sleep. The quality of human sleep depends on the body constitution and the external environment. Human constitution belongs to the medical category, so we can't talk about it here. We can only talk about the external environment. When we talk about the external environment of sleep, we have to talk about the "microenvironment" of sleep. The so-called "microenvironment" refers to the "quilt climate" formed by the human body and bedding during sleep. Generally speaking, the more standard microenvironment is 32-34 ℃, the relative humidity is 50-60%, and the air flow speed is 25cm / s. under this condition, the human body feels very comfortable and can effectively extend the time of deep sleep. Too high quilt temperature will lead to sultry body, too low human body will curl up and stretch, which will interfere with normal sleep and reduce sleep quality.
What is the relationship between microenvironment and down? To understand this problem, let's first explore the secrets of the down micro world!
Down is a mixture of "feather" and "down". A duck can usually produce 150-200g of raw material down, of which only more than 10g is duck down, and the rest is wool. Feather is a piece of hair, which plays a supporting role in down; And down is the down flower, which is the essence and value of down.
The cashmere flower is a three-dimensional spherical structure, consisting of a cashmere core and many emitted cashmere filaments. Each cashmere core grows 20 ~ 50 cashmere filaments, and each cashmere filament can grow secondary cashmere filaments. Its overall structure is like a tree fork, which is also like the seed of dandelion. Velvet filaments are composed of thousands of tiny scales, each scale is hollow, and each velvet filament has a dense water repellent molecular layer membrane on its surface. There are many hollow rhomboids on each pile, a bit like bamboo.
Such a wonderful structure is formed by the evolution of ducks and geese over a long period of time. It is also a gift from nature to human beings. Then, what is the role of such a structure?
1、 Warmth retention
Among solids, liquids and gases, the thermal conductivity of gas is the lowest, which is also lower than that of various fibers. The thermal conductivity is small, the heat transfer is small, and the ability to maintain temperature is strong. Down has excellent thermal insulation: first of all, because down has a three-dimensional spherical structure, a large number of radial down filaments, and thousands of hollow scales and hollow rhomboids on the down filaments, it can fix a large amount of air and prevent heat loss from the human body;
Secondly, because there are secondary down filaments on the down silk fibers, when many down feathers are mixed together, the down filaments intertwine with each other, and the secondary down filaments overlap with each other, forming multiple obstacles to prevent the free flow of air; Thirdly, the oil on the surface of the velvet fiber, the dense water repellent molecular layer film, and the relatively compact arrangement structure inside the fiber effectively control and balance the entry of water molecules and air flow. These are the three secrets of why down is so warm.
Fluffy refers to the volume cubic inch of each ounce (30g) of down under certain conditions. If the space occupied by an ounce of down is 600 cubic inches, the puffiness of the down is said to be 600. The more fluffy the down is, the larger the volume of air layer can be fixed by the down under the same filling amount.
The down has good fluffy property. First of all, because the down with tree branch structure occupies a larger space, the down filaments and secondary down filaments are closely arranged and keep a certain distance from each other, and the rhomboid nodes on them play a role of support and recovery after the fiber is compressed; Secondly, the surface of down fiber is in the shape of deep or shallow grooves, and the friction coefficient of down branches is not as high as that of wool, which is highly dispersible; Again, the moisture absorption is not as obvious as that of wool, which makes it easy to fluff and not easy to bond.
When tested with down with a down content of 50%, its lightness and fluffy degree are equivalent to 2.8 times of cotton and 2.2 times of wool. Compared with down, cotton, silk, chemical fiber, wool and other fibers are linear, which not only requires less fixed air volume, but also will harden after long-term use, affecting thermal performance and comfort, while down will not harden, and will still be fluffy after long-term use.
Softness is a comprehensive concept of physics and mechanics. Affecting the comfort of wearing. At present, there is no complete evaluation system. So, what is the difference between fluffy and soft?
For example, flour is soft but not fluffy, and bread is soft and fluffy; Silk is soft but not fluffy. The main reason for the softness is that the down fiber is short and thin, and the fiber surface contains a certain amount of fat, and the friction coefficient between the fibers is very small. On the whole, down is thinner and softer than wool.
4、 Air permeability
The down has a branching structure and a large number of radial down filaments. There are a large number of gaps between the down filaments and thousands of hollow scales and hollow rhomboids on the down filaments, which can fix a large amount of air. In the process of using the product, when encountering external extrusion and a certain speed of air flow, the air contained in the down will flow, forming a good permeability. The air flow speed in the down is too fast, the permeability increases, and the warmth retention decreases; On the contrary, the air permeability decreases and the warmth retention increases.
Compared with the down quilted by the upper and lower fabrics, the naked down has better air permeability and the latter has better warmth retention. Therefore, the fabric of down products is generally configured with high count and high density. In addition to preventing the down from running, it also plays a role in controlling the speed of air flow in the down and balancing warmth and permeability.
5、 Moisture absorption and dryness
The moisture absorption of down is far lower than that of wool and slightly lower than that of cotton. However, the balance between moisture absorption and dryness of down is very prominent, which is a special function formed based on the amphibious lifestyle of ducks and geese for a long time.
According to the measurement, the human body continuously emits sweat when sleeping. An adult emits about 100g of sweat overnight. Down can constantly absorb and discharge the sweat released by the human body, so that the body does not feel damp and stuffy.
The hygroscopicity of down, first of all, should be that it belongs to protein fiber and contains hydrophilic groups such as amide group, hydroxyl group, amino group and carboxyl group similar to wool; Secondly, due to the complex branching structure of down and the small fiber diameter, the specific surface area, surface energy, water absorption and easy drying ability of down fiber are significantly increased; Thirdly, the oil on the surface of the down, the dense water repellent molecular layer film, and the relatively compact arrangement structure inside the fiber effectively control and balance the entry of water molecules and air flow, and at the same time have the functions of moisture absorption and easy drying. This is also one of the important reasons why ducks and geese do not wet their feathers when swimming in the water, and they can be dry when they go ashore and shake lightly.
Seeing this, do you feel a little brain burning?! It doesn't matter. I'll summarize it briefly and draw a key point! First, the special branches and hollow microstructures of down lead to the mutual correlation, intersection, opposition and unity of their performances, which is beyond words; Second, down has excellent warmth, fluffy, soft, breathable and good moisture absorption and easy drying performance; Third, compared with other fibers, it is more conducive to the formation of the microenvironment, and the microenvironment is more conducive to sleep, so the duvet is more conducive to sleep.