Milk fiber is mainly made of milk. The source of raw materials is abundant, and high-tech processing is used in the production process, which will not cause pollution to the environment. Therefore, milk fiber fabric is known as the green fiber of the 21st century.
What Is Milk Fiber?
Milk protein fiber uses cow’s milk as the basic raw material. After dehydration, deoiling, degreasing, separation and purification, it becomes a kind of cheese protein with linear macromolecular structure; then it is blended with polyacrylonitrile by high-tech means. Cross-linking and grafting to prepare spinning dope; finally, it is formed by wet spinning into fiber, curing, drawing, drying, crimping, setting, short fiber cutting (filament winding).
It is a new type of animal protein fiber which is different from natural fiber, regenerated fiber and synthetic fiber. People also call it milk silk.
Morphological Structure of Milk Fiber
The cross-section and longitudinal surface morphology of milk fiber were observed with an electron microscope as shown in the figure. The cross-section of the fiber is flat, dumbbell-shaped or round, which is a special-shaped fiber, and there are small micropores in the cross section. These small micropores have a great influence on the moisture absorption and moisture permeability of the fiber.
It can be seen from the figure that the longitudinal surface of the fiber is not smooth, with irregular grooves and island-like concavities and convexities. These grooves and concavities and convexities are formed during the spinning process due to the dehydration and rapid orientation of the fiber surface. Existence is the main reason why the fiber has good moisture permeability, excellent moisture absorption and moisture release performance, and it also has an important impact on the gloss and stiffness of the fiber.
The roughness of the fiber surface and some subtle abrupt changes can change the absorption, reflection, refraction and scattering of light, thereby affecting the gloss of the fiber. When the fiber surface is rough, it has a soft luster without the “aurora” phenomenon. The milk fiber has a certain degree of curling, the appearance is slightly yellow, and the hand feels soft.
Advantages of Milk Fiber
- The softness and skin-friendliness are equal or better than cashmere;
- Breathable, good moisture conductivity, and good fit;
- Good warmth retention, which is close to cashmere;
- The abrasion resistance, pilling resistance, colorability and strength of milk velvet are better than cashmere;
- As milk protein contains amino acids, the skin will not reject this fabric. It is quite the same as a layer of human skin, and has a protective effect on the skin.
Advantages of Milk Fabric
- More comfortable: excellent moisture conductivity and breathability
- The material extracted from milk, combined with high technology, its unique function is mixed with other fibers, which not only retains the original fiber characteristics, but also improves the function and quality of the fabric.
- Healthier and greener: weak acidity and good affinity with skin.
- More colors: After washing for many times, the hand feel, color and surface remain unchanged. The affinity with dyes makes the color extra bright and vivid.
Properties of Milk Fiber
- Physical and Chemical Properties
It is not only different from natural fibers such as cotton, linen, silk and wool, but also different from chemical fibers such as nylon, acrylic, polyester, and polypropylene, so its performance is between natural and synthetic fibers. The physical and chemical index test values are as follows: dry breaking strength ≥2.5cn/dtex; dry breaking strength variation coefficient ≤14%; dry breaking elongation 16.0%～25.0%; dry breaking elongation variation coefficient ≤12%; linear density deviation rate is ±4.0%; the linear density variation coefficient is ≤3.5%; the uniformity of dyeing (gray card) is ≥3 ～ 4; the moisture regain rate is 4% ～ 6%; the fiber inhibition rate is ≥80%.
Without using formaldehyde azo additives or raw materials, the fiber formaldehyde content is zero; it is rich in 18 kinds of amino acids that are beneficial to the human body, which can promote the metabolism of human cells, prevent skin aging, itching, and nourish the skin; it has natural moisturizing factors, so it can maintain skin moisture content, make skin soft and smooth, and reduce wrinkles; it has broad-spectrum antibacterial function, strong durability, natural antibacterial function of over 99%, and antibacterial rate of over 80%.
It has a cashmere-like feel, with fine monofilament size and light specific gravity. Its elongation at break, crimp elasticity, and crimp recovery are closest to cashmere and wool. The fiber is bulky and soft, and the touch is as soft, comfortable and smooth as cashmere. The fiber is white with silky natural luster and an elegant appearance. Its fastness to sunlight and perspiration reaches 4~3 levels.
The cross-section of milk protein fiber is irregular round, with gaps in the cross-section and many grooves in the longitudinal direction. The protein molecules are distributed on the surface of the fiber. It contains natural protein moisturizing factors and a large number of hydrophilic groups, which can quickly absorb human sweat through the grooves. The trough is quickly introduced into the air and emitted, so that the skin is always kept dry, and the anti-pilling and pilling properties reach 3 to 4 levels.
- Endothermic And Exothermic
The three-dimensional microporous structure of the fiber and the groove structure on the longitudinal surface determine that the fiber has the characteristics of warm in winter and cool in summer: it is made into a thin silk fabric in summer, which can quickly absorb moisture and sweat from the skin, and quickly diffuse into the air to maintain The skin is dry and breathable; in winter, it is made of a thick fabric, and the micropores absorb the heat emitted by the body, effectively blocking air circulation and preventing cold air from intruding to achieve the effect of keeping warm.
- Other Properties
Dyeing under normal temperature and pressure, the color is bright, soft and shiny. The dyeing rate is high, and the color fastness is 4~level. After dyeing, the original performance of the product is maintained, and it has excellent safety. It has a natural antibacterial function and is more mildew and mothproof than wool and cashmere. It has high strength, is durable and washable, and is easy to store. It is easy to dry after washing, and the permanent performance of the product can be maintained after washing.
Detection Methods of Milk Fiber
- Combustion method: close to the flame: melting and curling; touching the flame: curling, melting, burning; leaving the flame: burning, sometimes self-extinguishing; burning smell: burning smell; residue characteristics: black, basically crisp, but extremely Tiny lumps. Judging from the above combustion characteristics, it is very similar to protein fibers such as silk.
- Infrared spectroscopy analysis: It can be known from the infrared spectroscopy that the milk fiber contains NH, -CH3, -C≡N,>C=O and other groups. The milk fiber is grafted with acrylonitrile and amino acids extracted from milk. But its infrared spectrum is not only different from natural protein fibers such as silk and wool, but also different from acrylic fibers.
- Melting point method: No melting point below 300℃, same as hemp, cotton and other non-melting fiber.
- Slicing projection method: Use a Hastelloy slicer to slice the fiber longitudinally and cross-sectionally, and place it in a 500-fold projector to observe the results: longitudinally with hidden stripes and smooth edges; the cross-section is round, like synthetic fibers.
Application of Milk Fiber
The important raw material for the production of milk fiber is milk protein, so it contains 17 kinds of nutritious amino acids, and it also has a natural and long-lasting antibacterial function. It has a broad-spectrum antibacterial rate against Staphylococcus aureus, Candida albicans, fungi and molds. More than 80% of home textile and clothing products can moisturize the skin due to the active protein in the fiber.
A home textile fabric that is blended and interwoven with milk protein fibers and other fibers. The texture is fine and light, breathable and smooth, the fabric is elegant and luxurious, and the color is gorgeous.
Milk made of milk protein fiber velvet as filler is docile and soft, has good thermal insulation properties and is full of elasticity. It has the functions of promoting sleep, preventing mites and antibacterial, and is beneficial to health. It is especially suitable for people with allergies.
Milk protein fiber home textile products are easy to keep, except that strong alkaline detergents are not used when washing, and no special treatment is required. In daily use, it can stay bright as new for a long time and is easy to take care of.