A complete piece of down looks the same, but it needs to be enlarged under a microscope to distinguish whether it is duck down or goose down.
Recently, Nandu Appraisal “Quality Open Class” entered the down testing laboratory of Guangzhou Inspection Group, and discussed the quality topic of down products with senior engineer Liang Guowei.
Why do dust velvet and glue velvet appear?
It is understood that there are two main standards currently implemented for down clothing: one is the national standard GB/T 14272-2011 “Down Clothing”, and the other is the industry standard FZ/T 73053-2015 “Knitted Down Clothing”. Liang Guowei introduced that these two standards have an important index for the down filled in down jackets called “down content”. Down is mainly composed of four components: “down”, “feather”, “feather silk” and “down silk”. “Down” is a three-dimensional spherical shape, which plays a key role in the warmth of down jackets. The raw flakes are “feathers”, and the strands that fall from the “feathers” are called “feather silks”, and the strands of silk that fall from the “down or the root of the flakes” are called “velvet silk”. The down content is the percentage of “down” + “down silk” in the total weight of down.
Why are there dust velvet and glue velvet? Liang Guowei said that in recent years, the price of domestic down raw materials has been rising all the way. Driven by profits, news about doping of down raw materials and fake news have emerged one after another. Phenomena such as “glue down” and “dust down” continue to appear. Among them, “glue velvet” refers to the use of chemical additives with special properties or special processing techniques and other unconventional methods in the production and processing of feather down to increase the weight of down or add down, feather silk, land poultry hair, Dust, etc. adhere to the down, thereby increasing the down content of down products, so as to achieve the purpose of shoddy.
The “dust down” is a powdery mixture composed of ultra-short down filaments and feather silks formed by the damage and breakage of down and feathers during the production process, which is added to the down and adhered to the down. “Dust velvet” is objectively difficult to completely eliminate during the production and processing process.
Poor-quality down can easily induce allergies and irritate the respiratory tract
Compared with high-quality down, can consumers distinguish glue down from dust down? At the site of the quality open class, Liang Guowei first grabbed a handful of normal down with his hands. After spreading his hands, the normal down can spread out naturally and has good resilience. Afterwards, under the same circumstances, the resilience performance of the glue fleece is very poor. “The obvious appearance characteristics of glue velvet are serious bonding and inconspicuous velvet core.” Liang Guowei introduced that glue velvet generally has more velvet, feather silk, land poultry hair and dust stuck to it, and its resilience is poor, or There are “cocoon” and rice-grain down, which are sometimes difficult to identify from the appearance alone, and a comprehensive evaluation must be combined with microscopy and chemical methods.
In contrast, there is more dust stuck to the down of the powder-dust velvet. Shaking the down sample by hand will scatter more powdery substances, which float in the air and easily adhere to the palm of the hand. What are the harms of shoddy down, such as dust down, to the human body? Liang Guowei believes that shoddy down, especially down with a high dust content, can easily induce allergies and irritate the respiratory tract during use. “Under the action of respiration, dust can easily enter the human respiratory system and have a certain impact on the human body. “
In order to select good down, the group standard “Inspection Method for Net Down Content and Number of Down ” jointly issued by Guangzhou Inspection Group and China Down Industry Association puts forward the concept of clean down. Liang Guowei introduced that the traditional “velvet content” includes the weight of some velvet threads interspersed and entangled in the velvet in the form of a single strand. When testing, it is only necessary to clamp the velvet one by one and shake it gently for 5 times. The fleece can be weighed and the percentage calculated by deliberately separating the fleece that is interspersed and entangled in the fleece. The “clean velvet content” does not include the velvet that is interspersed and entangled in the velvet in a single form. During the test, the velvet that is interspersed and entangled in the velvet needs to be completely picked out before weighing and calculating the percentage content.
In addition, in the group standard “High Quality Down Products”, higher requirements are put forward for the “loftiness” of down. Liang Guowei said that generally speaking, the larger the down, the higher the net down content, the higher the bulkiness, and the warmer it is. Liang Guowei also reminded consumers that high-quality down jackets should meet three conditions: the bulkiness should be good, the better the bulkiness, the better the thermal performance of down jackets; If it is caused by adequate disinfection and cleaning, it is recommended not to buy it; the third is that the texture should be soft, and it should have a good anti-drilling function to give consumers a better wearing experience.
Post time: Apr-28-2023