Application of silk in clothing industry
Silk fabric has the characteristics of comfortable wearing, soft and smooth hand feeling, harmonious luster, gorgeous and noble. Therefore, it has always been favored by people. The regular moisture regain rate of silk is 11%, and it has excellent moisture absorption and moisture permeability, so that the silk fabric has the function of adapting to the external temperature changes and adjusting it in time, so that the body surface always maintains a certain amount of moisture and prevents the skin from drying out. The thermal conductivity of silk is less than that of most textile fibers, and the heat dissipation speed of silk clothing is relatively slow, so people wearing silk clothing can feel warm in winter and cool in summer.
Silk has high hygroscopicity and heat absorption (165eal), second only to wool. Therefore, silk clothing has a good buffering effect on temperature changes. The content of tyrosine in mulberry silk is as high as 42.8%, and tyrosine can act with ultraviolet rays. Therefore, silk clothing can prevent or reduce the damage of ultraviolet rays in sunlight to the human body and protect the skin. And the silk protein fiber is not easy to generate static electricity. Silk clothing is prone to fibrillation after being worn and used. Fibrillation is like a broom or brush, which can remove tiny dirt and bacteria on the surface of the human body and prevent skin pruritus. Therefore, some people call silk a "health care type". fiber".
In order to overcome the shortcomings of real silk fabrics such as easy wrinkle, single species, easy yellowing, poor dyeing degree, etc., composite raw silks such as core-spun silk and textured silk have been developed, and they have become the main direction of its development.
Application of silk in cosmetics
As early as the China Ming Dynasty, Li Shizhen recorded in his medical masterpiece "Compendium of Materia Medica" that natural silk can make the skin beautiful, eliminate dark spots, and treat purulent skin diseases. In cosmetics, silk has two main forms: silk fibroin powder and silk peptide. Silk fibroin powder not only has the unique soft luster of silk protein and the function of absorbing ultraviolet rays to resist solar radiation, but also is smooth, delicate, good air permeability, strong adhesion, and can absorb and release moisture with the change of environmental temperature and humidity. Keep the moisture of the stratum corneum of the skin. Therefore, silk fibroin powder is a superior basic material in beauty cosmetics. Silk peptide has a good moisturizing effect; strong permeability, can combine with epithelial cells through the stratum corneum, participate in and improve the metabolism of epithelial cells, nourish the cells, make the skin moist, soft, elastic and shiny; have good performance Membrane, it can form a protective film on the surface of the skin and hair. This film has good flexibility and elasticity; it prevents ultraviolet radiation, and the tyrosine in the silk fibroin peptide reacts with ultraviolet light to prevent and reduce the effect of ultraviolet light. Invasion of the human body; inhibit the production of melanin in the skin, silk peptide protein has the effect of inhibiting the activity of tyrosinase, thereby inhibiting the production of melanin.
The effective rate for treating pruritic skin diseases and chapped skin is 95%. In 1992, Japan used silk fibroin powder to successfully develop a series of cosmetics such as foundations, pressed powders, face creams, solids, shampoos, hair protectants, lipsticks, etc. Silk protein is used as a cosmetic additive and its main advantage is good thermal stability. It has complete functions such as sun protection, moisturizing, nutrition, etc., and has good compatibility with other cosmetic raw materials. The addition amount is large, up to 20%, which makes its functional effect more obvious, so it can be widely used in the field of cosmetics.
Application of silk in food
Silk has the characteristics of non-toxic, non-polluting, and biodegradable, and its degradation products and oligopeptides in the silk have special nutritional and health care functions for the human body. Silk protein is rich in 18 kinds of amino acids, including 8 kinds of essential amino acids, while the fat and carbohydrate content is very small. The biological food developed by silk not only meets the requirements of modern human nutrition, but also has special medicinal value. It is called "the high-tech food of the 21st century". The silk food can relieve alcohol, reduce blood cholesterol, and promote insulin Secretion, lower blood pressure, prevent and treat Parkinson's disease, and have obvious antibacterial effects. Silk fibroin food originated from Japan. At present, silk fibroin cakes, biscuits, noodles, soba noodles, jelly gum, ice cream, candy, rice porridge, beverages, soy sauce and tea containing silk fibroin ingredients, capsules, tablets, etc, which are favored by consumers for their unique qualities, and have become a new generation of health foods and nutritional products in Japan.
The success of the development of silk fibroin food has virtually increased the added value of silk products and reduced the cost of raw materials, which is of great significance to the change in the product structure of functional foods. In the production process of raw silk, there are sufficient leftover cocoons and waste silk raw materials, and there is also a broad consumer market. Therefore, the development and utilization of silk food will have a very broad prospect.
Application of silk in medicine and medical materials
Silk protein has a special ultrastructure and hierarchical structure, and has the unmatched advantages of other polymer materials: non-toxic, non-irritating, non-polluting and biologically compatible, and can adapt well to body tissues. With these properties, breakthroughs have been made in artificial skin, artificial blood vessels, artificial tendons and ligaments, artificial bones, artificial teeth, non-removable surgical sutures, silk fibroin membranes, and bioreactors . Studies have shown that due to the biocompatibility and suture of silk protein, silk protein microtubules are ideal biomaterials for microtubule transplantation, whether it is directly transplanted or grafted onto cells. In recent years, many researchers have devoted themselves to the application of silk protein in medicine and medical materials, in order to havebreakthroughs in the research of anti-cancer drugs, anti-AIDS drugs, anti-aging, and drug release control by using its unique properties and advantages.
Application of silk in biotechnology
In the field of biotechnology, silk fibroin membrane can be used as a carrier for immobilized enzymes and to prepare biosensors. The unique molecular structure of silk fibroin, excellent mechanical energy, good moisture absorption and heat preservation properties, and antimicrobial properties make it an ideal enzyme immobilization carrier material for medical, biochemical, fermentation and chemical analysis And other fields. People in China have been studying the use of silk to immobilize penicillin acylase. And made some progress.
The enzyme sensor prepared with silk fibroin membrane can reduce enzyme inactivation, expand the pH range of enzyme activity, and improve the utilization efficiency of enzymes. In addition to enzyme sensors, silk fibroin membranes can also be used for immunosensors and nerve sensors. Nippon Knitting Corporation has also developed a silk fibroin membrane to immobilize antibodies, and developed an immunosensor for cancer diagnosis
Development and application of silk in the environmental protection market
The waste of polymer plastics has caused serious white pollution. Silk is a natural fibrous protein, which can be quickly decomposed under the action of ultraviolet rays, microorganisms and biological enzymes in the natural environment. Therefore, silk fibroin film is receiving attention as a substitute for polymer plastics. The composition of silk fibroin is similar to that of tortoiseshell and can be used as a substitute material for tortoiseshell; silk has also been used as a substitute for ivory. The fishing line made of synthetic fibers such as nylon will not decompose and cause environmental pollution under natural conditions. A pollution-free fishing line made by covering silk with light-hardening resin has been put into practical use. After the silk is treated with alkali, a new type of tactile coating material can be obtained by adding a certain proportion of resin. The silk powder can be mixed into some coatings to make advanced coatings which currently widely used in various high-end interior decorations.