丨About Down Feather
As a filling material for down products, down and feathers are derived from the body surface of ducks and geese, and are by-products of the goose and duck meat food industry.
In China's total down production, duck down accounts for about 90% and goose down accounts for 10%. Because there are many people in China who like to eat duck meat, the growth cycle of ducks is short, generally about 40 days, and they can be hatched and slaughtered every day, regardless of seasons.
The growth cycle of geese is longer, it takes 5-6 months, and it can only hatch once a year in spring, and there are few people who like to eat geese. Therefore, the output of ducks is much higher than that of geese.
a. Due to the short growth cycle of ducks, the development of large-scale breeding and large output, the price of duck down is relatively lower than that of goose down, so it is impossible to live plucking in the process of duck breeding and slaughtering;
b. "Live plucking" originated from the ancient custom of assisting geese to moult during the shedding period in Eastern European countries, and only exists in very few geese populations. Since it was introduced to my country in the last century, "live plucking" has not been widely adopted by goose farmers because it is contrary to animal welfare protection and high production costs.
Since 2009, with the attention and supervision of animal protection organizations, and the China Feather and Feather Industry Association's call for "rejecting live poultry products" in the industry, it has been difficult for the behavior of "live plucking" to gain a foothold in China's down industry land. Due to the continuous improvement of labor costs and the increase in the death rate of geese caused by live plucking, no one is willing to do the business of live plucking anymore.
Down, a by-product of the poultry industry, contains at least 80% protein and is a natural product that degrades naturally.
Since people have a long-term demand for goose and duck meat, and down is the most comfortable and warmest natural thermal insulation material, there is a stable market demand for down products, so the production of down and feather will be a permanent and sustainable development.
Chemical fiber, cotton, wool, silk and other linear fibers have poor compression resistance, are easy to harden, and the material degrades quickly; because down itself is three-dimensional spherical and rich in stagnant air, it will never harden after years of use, and its function can be guaranteed for a long time like New. Generally, the service life of duck down quilts is 10-15 years, and that of goose down quilts can be as long as 20-30 years.
Down is animal protein, and it will not burn at a temperature below 100 degrees Celsius, so down can pass the flammability test; but other materials, especially synthetic materials, need to be treated with fire protection to pass the same test; in California, the United States, the duvet The fire resistance is an exempt item.
The three-dimensional spherical structure of down down determines its large surface area, so it will quickly dissipate after absorbing water. In addition, down itself contains a certain amount of oil, which has good moisture absorption and moisture drainage.
The thermal performance of down has to start with the way of heat transfer.
Generally speaking, heat is mainly transmitted in three ways: conduction, convection and radiation. In the cold season, the heat of the human body is also dissipated to the surrounding colder space through these three ways. But in the case of wearing clothes or covering the quilt, the heat dissipation is mainly conduction. This requires that the thermal conductivity of the thermal insulation material should be low.
Feather down has the characteristics of low thermal conductivity.
High-quality down has a high loft, which is unmatched by any other thermal material. The loftier the insulation, the more voids there are between the fibers of the material and the more air it can hold without moving.
Air is a poor conductor of heat, which can prevent heat from being conducted to the surroundings. Therefore, the higher the bulkiness, the better the thermal performance. If the difference in thermal conductivity between fabric fibers is not considered (in fact, the difference is very small), then the thermal conductivity of down products is 20-50% lower than that of ordinary fabrics of the same thickness, that is, the warmth retention is 1-4 times higher.
The higher the density of the product filler, the greater the thermal conductivity and the more heat lost. Down with a high down content has a higher bulkiness, so that the product has a lower density under the same thickness, so it has higher warmth retention. Therefore, the use of down with a higher down content can properly reduce the weight of the filler, which can not only obtain the same warmth retention, but also reduce the weight of the product.
This is why down products have the characteristics of "light, soft and warm".
The higher the down content of down, the higher its bulkiness, the better the relative warmth retention and the more comfortable it is. The down content of down is not 100%, unless it can be achieved by manual selection, and the down content of machine sorting can reach up to 95%.
The down filling must contain a certain proportion of small flakes, because the flakes can rebound quickly. Therefore, determining the appropriate down content can relatively reduce the amount of down filling and achieve the same purpose of keeping warm.
The main production areas are concentrated in Asia and Europe.
Asia is represented by China, the world's largest feather producing area, as well as Japan, South Korea, Vietnam and Taiwan; at present, China is the world's largest producer, exporter and consumer of down and feather products, and its export volume occupies the international market More than 70% of the share; Europe is represented by Hungary, Poland, Germany, and France; in addition, North America, Canada and other countries also produce feathers.