A New Technology Of "One Step Spinning" In China

Our country pioneered the "one-step spinning" technology, which was developed by the Changshou City Changjiang Chemical Fiber Co., Ltd. and the Changchun Institute of Chinese Academy of Sciences in 2008 6, and was certified by experts from the China Textile Industry Association. This is a kind of polylactic acid filament that can be completely biodegraded without any difference between physical properties and the marketed polyester filament and nylon filament. The new technology, new process and polylactic acid filament yarn developed by continuous polymerization melt direct spinning have filled the gap in China and will bring great changes to China's chemical fiber, textile and garment industries. Polylactic acid fiber is a new type of high molecular fiber material obtained from corn starch by means of bacterial fermentation and chemical synthesis. Because it has both the physical characteristics of chemical fibers and the green environmental characteristics of natural fibers, it also has a broad and deep downstream industry chain. Since its early twenty-first Century, it has rapidly become one of the hot research directions of the international textile and garment industry and the major demand of the country. Jing Xiabin, a researcher at the Changchun Institute of chemistry, Chinese Academy of Sciences, and his research team focus on the development direction of polylactic acid fiber, and cooperate with Changshou City Changjiang Chemical Fiber Co., Ltd., a strong domestic chemical fiber industry. Since 2006, "continuous polymerization melt spinning technology and technology of polylactic acid fiber" have been organized. Through unremitting efforts, the key technologies of dehydration polymerization, cracking and purification, ring opening polymerization and post-processing were broken through, starting from aqueous lactic acid solution, directly spinning from lactide to polylactic acid melt, and spinning PLA into filament for the first time in November 2006. On this basis, they independently developed a continuous polymerization direct spinning device whose core capacity is "membrane reactor", with a production capacity of 50 tons / year. It solved a series of engineering and technical problems such as material entry and exit, mixing and propulsion, temperature measurement and control, and broke through the technical problems such as transition between atmospheric pressure, vacuum and high pressure in the process of material progress. In November 2007, they successfully produced polylactic acid filament on the device at a spinning speed of 2800~5000 M / s. The test and dyeing tests of Jiangsu fiber inspection institute show that the filament size of the PLA filament is 2 ~ 4dtex, the breaking strength is more than 3.0cN/dtex, the elongation at break is 20% to 30%, the shrinkage rate of boiling water is less than 16%, and the color fastness is 5 or 4~5, which is basically the same as that of polyester and nylon filament sold in the market, and the main technical index reaches the level of the American slice spinning PLA fiber. Experts believe that at present, the fiber grade polylactic acid chips and their production technology can not be imported from abroad, the result has designed and built a 50 ton / year continuous polylactic acid continuous spinning direct spinning filament device based on thin-film reactor. The new technology of "one step spinning" has been created. It has not only filled the gap in China, but also shortened the process flow compared with the "slice spinning" adopted by the US and Japan, reduced the melt pyrolysis and lowered the production cost, guaranteed the fiber quality, and enhanced our competitiveness in the international polylactic acid market. This is of great significance for promoting the industrialization of polylactic acid resin and fiber, extending the industrial chain of corn, and promoting major changes in the textile and garment industry. Yang Jing: editor in charge