Covers of birds
The bird’s feather is often called the miracle of the engineering nature`s art. It is characterized by lightness, strength, plasticity, elasticity, the ability to restore the damaged structure.
The structure of the feather is difficult — from its quill go barbs, each of which has on itself barbicel, equipped with outgrowthsin the shape of hooks, which ensure the linking of the barbswith each other’s.
On the one bird`s feather under a microscope, you can count hundreds thousands of barbicels and millions of their outgrowths with hooks.
Each contour feather includes such components as the quill and vanes, usually asymmetric, formed by the system of barbs. Closer to the quill vanes have a down part, the barbs of which are thin, long and not linked to each other. Often on the line between the quill and the dense part, an additional quillappears. It has small vanes or can be replaced by a nubble of down.
In addition to typical contour feathers, birds have down feathers. Their quill is thin, and the bards are very soft, long, and not linked to each other. If the quill is shortened and soft bards go from one point, this formation is called not a feather, but a down. The realdown and down feathers are connected by a number of transitions.
A similar structure is characteristic of contour feathers, which determine the outlines of a bird. The most important among contour feathers are wing feathers and tail feathers, which form arudder . The number of feathers of different birds are not the same, they require careful care. For birds, as for reptiles, a moult isa characteristic
Contour feathers do not grow throughout all body of the bird, but in certain areas of the skin, between which are the areas of the skin without feathers. This feathers` arrangement provides greater freedom of birds` movement in flight. In all flying birds, these areas are clearly marked. In ostrich birds and penguins, contour feathers evenly cover the whole body, they do not have feather-free areas.
Feathers are modified horny scales similar to scales of reptiles. Real scales can be seen on the unfledged areas of bird legs. Horn shells on birds’ nibs and claws have the same origin as feathers.
Why down anyway?
From the earliest times one of the main human needs was warm. Man warmed his body with fire or clothes. To do this, he used all the materials available in nature: animal`s skin and wool, down and feather of birds.
Over time, most of the natural heaters were replaced with modern synthetic equivalents. But only not down, he is an exception. The main unrivaled advantages of down are lightness, extremely high heat-insulating characteristics, ability to shrink, and then restore volume, long service life. Down is able to decrease in volume several times, but it’s enough just to straighten and shake down clothes and it will quickly return to its original state. This is explained by the structure of down, consisting of individual fluffs, which on the one side they repel each other, and on the other side, they can tightly cuddle, under pressure.And with proper processing and storage, downy products be in use more than 20 years.
All attempts to copy down using various petrochemical products have not been successful. Analogues could not be compared with the original byheat /weight ratio, by size and volume, by service life. Until now, down remains the best naturalthermal insulation: lightweight, long live and at the same time completely recyclable.