Popular Science | The Lesser Cold and Greater Cold are approaching, and down jackets are the best way to save your life!

Winter is here, and it’s time for down jackets to come out again. But when you buy down jackets this year, have you noticed that the merchants’ introductions have changed “down content” to “down content”? In this issue, the editor will take you to understand what is going on~

It turns out that from April 1, 2022, the clothing industry began to implement the new national standard GB/T 14272-2021 "Down Clothing". This winter is the first sales season after the implementation of the new national standard. In this version of the standard, "down content" was changed to "down content".

"Down content" and "down content" seem to be just differences between the lines, but they have essential differences.

Down content refers to the mass ratio of down and down fibers in down feathers.

Down content refers to the mass ratio of down in down feathers, among which down includes flower down, similar down, immature down and damaged down.

Marking the down content can more intuitively represent the quality of down.

Flowery down refers to a down core that radiates many down fibers. The down fibers are long and spherical and scattered. It is the main component of down and has the best thermal insulation effect. Similar down refers to hair-like down with stems. The stems are thin and soft, and the tips are silky and messy. Immature down refers to down that has not yet fully grown and is umbrella-shaped. Damaged down refers to down that radiates two or more down fibers from a down core, which falls off the down during the down processing process. Down fiber refers to a single down fiber that falls off from the root of a down fiber or hair piece.

Down is the main component of down, and has the best thermal insulation effect compared with similar down, damaged down, and immature down. Under certain conditions, the larger the down, the longer the down branches, and the more down branches on the branches. Down has a unique spherical structure, and the down supports each other, which makes the down have a certain fluffiness, can accommodate a large amount of still air, and prevent air flow from taking away heat. At the same time, the thermal conductivity of air is small, which has a better thermal insulation effect. For a certain weight of down, under certain conditions, the higher the down content, the better the fluffiness and the better the thermal insulation effect. However, if there are a large number of down filaments in the down, because the down filaments do not have a unique spherical three-dimensional structure, the fluffiness is poor, and it is difficult to fix the still air, so the thermal insulation effect is poor, and the down filaments can easily drill out through the gaps between fibers and quilting, and the anti-drilling property is poor, which affects the appearance of the clothing.

The use of "down content" in the new standard is conducive to identifying the quality of down products and preventing unscrupulous vendors from taking advantage of loopholes by adding a large amount of cheap down yarn to the filling to increase the down content and pass off inferior products as good ones. At the same time, the new standard stipulates that the down content of down jackets must be no less than 50%. In other words, if the down content written on the label of the down jacket you bought is less than 50%, it cannot be called a down jacket, which is a fraud on consumers.

The implementation of the new national standard has shown us that the down jacket industry is developing in a positive direction. At least unscrupulous merchants can no longer deceive us with down fibers that do not keep us warm.

Let me tell you something. If the down jacket you are going to buy has the down content written on the label, you should think twice because it is probably the store’s stock from last winter. So how do you choose a down jacket?

Things to note when buying down jackets:

1. Check whether the implementation standard on the certificate is GB/T 14272-2021 "Down Clothing". Down jackets that implement the new national standard have significant improvements in quality, anti-down penetration, and environmental protection performance.

2. The new version of the down jacket standard no longer marks color differences such as white down and gray down. In fact, there is no obvious difference in the thermal insulation effect of the two.

3. The thermal insulation effect of down clothing is related to its fluffiness, but the higher the fluffiness is not necessarily the case, the better the thermal insulation effect. It is also related to the size of the down, the content of the down, and the amount of filling.

4. Check the filling amount. The filling amount of a down jacket has a significant impact on its warmth retention. Down jackets with a filling amount of 100g or less are usually suitable for temperatures above 0°C, down jackets with a filling amount of about 140g are usually suitable for temperatures above -5°C, down jackets with a filling amount of about 180g are usually suitable for temperatures above -10°C, and down jackets with a filling amount of about 200g are usually suitable for temperatures above -20°C. In addition, warmth retention is also related to the windproofness of the fabric, clothing style, length, etc. The specific temperature suitable for wearing a down jacket needs to be determined based on the results of the garment warmth retention test.

5. Squeeze the down jacket with your hands. If it has good recovery, it has good warmth retention. Rub the filling with your hands to see if there is any down. The soft and non-prickly feeling is better.

6. Smell the down jacket with your nose. If it has a strange smell, it means that its processing is not up to standard.

Author: Ding Lijin, Senior Engineer, Suzhou Fiber Inspection Institute

Bai Jie Director of the Science Popularization Department of China Textile Engineering Society

Editor: Liu Dan