The progress of modern science and technology not only brings convenience to human life, but also brings many potential hazards. The living environment is getting worse, electromagnetic radiation lurks everywhere, and harmful bacteria spread everywhere. As a kind of high-performance functional fiber, silver-plated fiber has attracted worldwide attention for its unique functions of antibacterial, deodorizing, electromagnetic radiation prevention, antistatic and body temperature regulation. It has been widely used in underwear, home textiles, special clothing, medical care, sports, military equipment and other fields, and has become a hot spot in contemporary functional fiber research and product development.
History and present situation of 1 silver-plated fiber
1. 1 fiber metallization technology
Tracing back to the history of silver-plated fibers, Germany, Israel and the United States took the lead in developing copper, nickel, silver and other metals on fibers as early as last century, and developed related products. Since then, Japanese, Russian and China have also invested in research and development in this field, and now there are many related patents [1-2,5,6]. At present, the application of silver-plated, copper-plated and nickel-plated fibers in radiation-proof textiles and clothing has become unique. Metal electroplating technology of fiber can be mainly divided into the following three categories [3]:
Electroless plating: metal ions are reduced and deposited on the surface of the base cloth by using the reducing agent in chemicals to form a metal film. Its biggest disadvantage is that wastewater containing heavy metal ions will be produced in the process of electroless plating, which is limited by environmental protection.
Electroplating: the metal ions in the solution are reduced by current to form a metal film on the surface of the coated fiber substrate.
Vacuum coating: metal is deposited and accumulated on the surface of textile materials in atomic or molecular state in vacuum to form nano-grafted metal film, thus realizing the surface functionalization of textile materials. It includes vacuum evaporation, vacuum ion plating and vacuum sputtering. Vacuum coating technology is the most advanced surface treatment technology in the world, and the metallization effect on the surface of textile materials is the most ideal.
1.2 varieties and preparation of existing silver-plated fibers
The world's largest brand of silver-plated optical fiber is X-static of Noble Fiber Technologies. At the beginning of its birth, chemical plating technology was adopted, that is, a layer of pure silver was plated on the surface of polyamide. At present, the fiber has been authorized by more than 100 manufacturers to put into production, but the price has been high, with sales reaching more than 40 million US dollars last year. In addition, Noble's sister company Sauquoil also developed a silver-plated fiber called Contax.
The research on silver-plated fibers in Japan is also very active. Toyoshima & Kloc-0/999, Ltd. developed silver-plated polyester fiber with the trademark μ-func. It is made of pure silver (about 1μm thick) coated on a transparent polyester film (9μm thick), covered with a polyester film with the same thickness, and then cut into thin wires with a width of 230μm or 150 μ m, and its structure is shown in figure 1. In addition, Mitsubishi Materials Company developed and manufactured silver-plated polyester fiber AGposs in 200 1 year, with a fiber diameter of 15-25 microns and a silver thickness of 0. 1μm [4], as shown in Figure 2.
Silver-plated fiber developed by domestic Jinan Liszt Fiber Co., Ltd. uses multi-target magnetron sputtering friction coating technology and composite electroplating technology to silver-plate polyester or nylon, and applied for invention patent in 2004 [5]. It is based on the fact that the chemical fiber substrate is not conductive. Firstly, a silver film was sputtered on the fiber surface by vacuum electroplating, and then silver was plated by electroplating. The process has the advantages of uniform coating, strong adhesion and washing resistance.