Discussion On The Scientific Use Of Down Jackets From The Perspective Of Keeping Warm

The original intention of the down jacket was to keep warm. The existing relevant standards for down jackets put forward more requirements on the surface accessories and down quality. As for the warmth retention of down jackets, affected by various factors, it has not been easy to quantify. It can only be left to the down jacket companies to use their historical experience to freely develop.

Therefore, down jackets on the market have a down content ranging from 50% to 95%, and a filling amount ranging from 20g to 500g. It is generally recognized that goose down is warmer than duck down, and the higher the down content, the more down filling. Down jackets are warmer.

Is the general perception of down jackets scientific and reasonable? Combining the research results of industry experts and the experience of thermal insulation testing of down jackets, the author discusses three scientific suggestions for the use of down jackets for industry reference.

One is to use duck down.

The second is to use 90 velvet for thin fabrics.

The third is to use 80 cashmere for thick fabrics.

1. Use duck down

The author has sorted out the bulkiness data of goose and duck down steam reduction method from a well-known domestic third-party testing agency. The content of down and down is more than 70%. The comparative statistical data of bulkiness are as follows:

In the case of the same down content, the ratio of the bulkiness of duck down to goose down=0.183/0.186=98.4%, that is, the average bulkiness of goose down with the same down content is 1.6% higher than that of duck down, which is the same as that of goose down with the same down content. The traditional perception that the bulkiness of goose down should be 1cm higher than that of duck down (the bulkiness of goose down is 6% higher than that of duck down) is far from that. In other words, goose and duck down with the same down content in the current domestic down jacket market has a high probability of being very close in bulkiness; the reason behind this should be inseparable from the current down jacket industry that generally uses young goose down with a low maturity According to the experience of the down industry, only when the breeding period exceeds 4 months, goose down will show a clear advantage of higher bulkiness compared with duck down.

Existing studies have shown that the warmth retention properties of goose down and duck down with the same down content and the same bulkiness are very close, and there is no significant difference. At present, the price of goose down with the same specification is about 1.8 times that of duck down. In terms of warmth retention and economy, duck down is the first choice.

2. 90 velvet for thin fabrics

The lighter and thinner the fabric of the down jacket, the more you can get the feel of down through the fabric. The main components of down are down, down silk, feather silk and wool flakes. The fibers of velvet, velvet and feather silk are slender, and they feel soft when grasped by hand; because of the harder feather shaft and sharp feathers, the feather flakes have a rough and thorny feel when grasped by hand. In order to obtain a soft feel for the down, the down factory will try to increase the proportion of down silk and feathers in the down on the basis of the down content required by the customer, and at the same time reduce the proportion of wool flakes to ensure that the down feels soft.

For down that meets the standard of GB/T 14272-2011 “Down Clothing” (referred to as the old national standard), the down factory will generally pile up a large amount of down and feather silk in the down to minimize the content of raw flakes, even if the down content is 70%. , can also get a good feel. With the official implementation of the new national standard of GB/T 14272-2021 “Down Clothing”, the down content of down content below 95% must not exceed 10%. The down factory has to increase the down content in order to meet the requirements of the new national standard. The content of flakes. Therefore, the lower the velvet content of the new national standard velvet, the higher the wool flake content and the worse the hand feel. Taking the velvet with a velvet content of 70% in the new national standard as an example, the content of velvet silk and feather is generally about 9%, and the content of raw flakes is about 20%. Compared with the old national standard, the content of raw flakes will double. Most consumers are not used to the soft feel of the national standard. For thin fabrics with a weight of less than 50g per square meter, consumers can easily perceive the feel of down through the fabric. Only when down jacket brand manufacturers use down with 90% down content can they compare with the old national standard down content of 90% down. similar to customer satisfaction.

Thin fabrics are generally used in light and thin down jackets. Compared with the old standard down content of 90% down, the fluffiness of down with 90% down content should be at least 5% higher. Under the premise of the same down filling weight, use A down jacket with 90% down content will have better warmth retention. Of course, enterprises may also reduce the amount of down filling with 90% down content in order to control costs. If the amount of down filling is reduced by no more than 5% compared with the old national standard, it will not affect the warmth retention of down jackets.

3. 80 velvet for thick fabrics

In 2007, Tang Liqiao, an expert signed by Hangzhou Xiaoshan National Down Products Quality Supervision and Inspection Center, published a paper titled “The Relationship between the Warmth Retention of Down Products and Down Quality”. In this paper, through detailed experimental data, the relationship between down content, down filling and heat preservation rate is discussed. This is also the first domestic paper that the author found to discuss the warmth retention of down, although it has been nearly 15 years , but the author believes that the conclusions in his paper are still applicable to the current down jacket products. In the paper, experts from Townley Bridge drew the following graph of “relationship curve between heat preservation rate and filling amount”.

Through the analysis of this figure, it can be known that when the filling amount per square meter of down products exceeds 133g (the area of ​​the down bag used in the experiment is 0.09 square meters), the insulation rate of down with 80% down content is basically close to that of down content with 90% down content ; When the amount of cashmere per square meter reaches 200g, the insulation rate of cashmere with 80% cashmere and 90% cashmere tends to be the same; The thermal insulation rate of fleece with 90% cashmere content shows a consistent downward trend. The author once analyzed the data of the thermal resistance of down jackets measured by the thermal manikin, and found that for down jackets filled with more down in winter, the down jackets with high down content and high bulkiness and the down jackets with low down content and low bulkiness should be used respectively. Filling, when the amount of down filling is similar, there is no significant difference in the warmth retention of down jackets. This conclusion is highly consistent with the research conclusion of Townley Bridge experts.

Considering that thick fabrics are generally used for winter down jackets with low temperatures, and the amount of down filling is generally more than 130g per square meter, from the perspective of warmth retention and economy, down jackets with 80% down content are the first choice. Down with a down content of 70% or less has insufficient warmth retention. The down content of more than 80% down increases the cost but does not increase the warmth retention, which has formed a significant waste of down resources.

In addition, thick fabrics generally feel hard, and with 80 down with about 10% raw flakes, consumers will not obviously feel the roughness and prickly feel of the raw flakes even if they touch the down jacket with their hands.

Coincidentally, a Canadian luxury down jacket brand is highly consistent with the author’s above three suggestions in terms of down jacket use. According to its official website, down jackets with thin fabrics generally use duck down with a down content of 90% and a bulkiness of 750inch3/30g, while thick fabrics generally use duck down with a content of 80% down and a bulkiness of 625inch3/30g. The author once thought that the brand’s 80 duck down jackets, which cost more than 10,000 yuan, seemed unkind. Later, I realized that the author was too naive. The brand’s selection of down materials has already surpassed Chinese brands by several positions.

2022 is the year when the new national standard for down jackets will be implemented on a large scale. The author sincerely recommends down jacket brand enterprises to use down scientifically and rationally, which can better demonstrate the confidence and soft power of Chinese down jacket brands.