Drilling down mechanism of down garments and test method of fabric anti-drilling down performance

Since the warm properties of feathers and down have been recognized and applied, down jackets have been favored by consumers at home and abroad for their softness, warmth and comfort. With the increasing improvement of people's living standards, down jackets are becoming more and more fashionable. The design of down jackets has changed from the traditional bloated and rigid image, but has become more and more thin and fashionable. It is not only winter clothing, but also the first winter fashion. main character. Nowadays, it is more and more common for a person to own several down jackets. While down jackets bring warmth and comfort in winter, they also bring troubles to some consumers. Drill down is one of the most prominent problems. Drilling down means that the feathers and down in the down jacket are drilled out of its fabric and lining. If the drill down is drilled inward, the feathers and down will stick to the sweater, or even get into the underwear, making people feel scratched all over, making people feel uncomfortable. If it is drilled outward, it will affect the beauty of the whole dress. Down floating in the air can also make sensitive people feel uncomfortable, and even cause respiratory diseases. For clothing companies, solving the problem of drilling down is also one of the factors for whether down jackets can step into high-end clothing. 1. Structural characteristics of feathers and down and the mechanism of down-drilling down jackets To study the down-drilling problems of down jackets, we must first start with the structural characteristics of feathers and down jackets. Feather refers to a substance that is light, tough, elastic and waterproof covering the body surface of ducks and geese, and is grown from the keratinization of the epidermis. Feathers can be divided into positive down feathers and fine feathers according to their structure. The positive feathers cover most of the body surface of birds and have a complete structure, which is composed of rachis, twigs and feather silks. There is a shaft-shaped hard stalk from top to bottom in the middle of it, called the rachis, (the upper part of the rachis is called the feather trunk, and the lower part is called the feather root). There are fine feather branches on both sides of the feather trunk. There are second-order twigs, and each twig can be regarded as a small“feather”, densely arranged on both sides with fine third-order pintlelets. Repeating this, a complete pinna is formed, which is what we usually call the hair piece (as shown in Figure 1). Under the microscope, the feather twigs show finer hooks, and the entire feather is woven together by these hooks (Figure 2). Down and feathers are distributed on the whole body of birds and are covered by the positive feathers to form an insulating layer. They are the most valuable part. According to their shape, they can be divided into fluffy down, immature down and similar down. The core part is fluff. The velvet is shaped like a“pom poms”,“pom poms”There is a very small nucleus in the center, called the velvet nucleus, from which many fine and slender filaments are radiated, called velvet filaments, and hairy twigs are grown on each velvet filament to form a flower-like velvet. (As shown in Figure 3), but for the more fully developed or larger florets, there will be secondary branches on the main branches. The name of the immature velvet is known as the unripe velvet, its velvet is short, has a small handle, and is umbrella-shaped (Figure 4). The velvet-like is hairy with stems, the stems are thin and soft, the feathers are dense, and the tips are filamentous and disordered (Figure 5). Under the microscope, the feather branches, feather silk and down silk of goose and duck will show a huge tree-like picture, the tree is composed of feather branches, feather silk and down silk.“trunk”, with feather and downy branches as“branches”, There are large and small Y-shaped or triangular nodes distributed on the feather branchlets and downy branchlets, the Y-shaped nodes are called hump nodes, and the triangular ones are called diamond nodes. The next-order feathers and down filaments extend from one direction or several directions at the node. Feathers are smaller than down feathers, shaped like hair, with only one stalk, from which there are few and short branches. The feathers are distributed in various parts of the bird's body. Its function is to feel the touch, and its value is not high ( Figure 7). Down fibers are protein fibers, but different from other protein fibers, from the perspective of their internal organizational structure, the basic unit is microtubule cells, and macromolecules are curled when forming microtubule cells, so a large number of down fibers are formed inside. The hollow and down fiber section is a hollow structure with the ability to contain still air. The fluff of the down is charged, and its electrostatic capacitance is extremely small. As long as a small amount of charge, the fluffs repel each other and separate from each other. In down jackets, down as filler, there are thousands of these fibers trying to keep the maximum distance from each other, so that the fluffyness is created, which squeezes the down close to the fabric outwards, thereby Generates an extrapolating force that keeps the down close to the fabric. When the garment is rubbed or squeezed by external force, the still air filled inside the down jacket will be drilled out from the gap of the fabric or the sewing needle eye of the connecting part of the two fabrics, and the down close to the fabric will also be drilled out of the gap with the air. It can be seen that drill down is related to the following three aspects: the down content of down, the density and thread density of the fabric, and the size of the gap left when the sewing thread passes through the fabric.