China began the commercial production of soybean fiber in 2001 in line with the call from China National Textile & Apparel Council (CNTAC). According rough statistics, over 500 textile mills have been concerned with the development and application of soybean fiber. In the course of practice, they focused the shortcoming of the fiber on following several sections: high price, static issue during yarn spinning, uneven printing & thermal shrinkage and easy pilling. Now with the commercial production, the price and performance of soybean fiber have already been accepted by downstream users.

Zhejiang Jiali Protein Fiber Co is a special producer for soybean fiber. According to Jin Xiaochun, the President of the company, since the soybean fiber was invested, it has been modified and upgraded for many times, forming current series products including colored, grey, whitened, cotton-type and wool-type etc. In price, it has declined to 35,000 yuan/ton from original more than 70,000 yuan/ton. And thanks to its excellent performances in moisture-conduction, air-permeability and skin comfort ability, plus the functions like anti-bacteria, anti-ultraviolet radiation and forming far-infrared ray & negative ion, its performance/price ratio has certain competition advantage. The development of textile process makes the soybean fiber able to be blended with any other fibers at any proportion, without problems in production. With fiber production process optimized, the protein content in all the lots can be fully the same with each other, which basically resolves the problem of dyeing uniformity. By choosing reasonable process parameters, the issue of high-temperature shrinkage is also solved. And by selecting blended components and adjusting spinning process, the problem of easy pilling is also improved, but it is not radically overcome at present.

In past few years, many universities, research institutes and textile enterprises have plunged themselves into the development of production technologies, and over a hundred of research thesis were published from them. Shanghai-based Dong Hua University, by adding some metallic salts into spinning dope, endows soybean fiber with far-infrared & negative ion and anti-bacteria functions. Only 3% such fiber is blended into blended yarn, can soybean fiber end products obtain stable and permanent anti-bacteria effect. Another technology from the same university is adopting ZnSO4 as the dehydrating agent for soybean fiber spinning. In the course of after-processing, ZnSO4 reacts with NaOH, forming ZnOH, which after drying is deoxidized into nano-grade ZnO that can form covalent bond with fiber itself, taking a strong screen effect to ultraviolet radiation. A college in Xi'an, China discovered a kind of dyeing mechanism and applied the technology into soybean fiber, increasing its dye-uptake from 70% to over 90%.

The main component of soybean fiber is quite similar to those of cashmere and silk, featuring fine denier, low density and good tenacity & elongation. The resulting fabric can give us cashmere-like hand touch, silk-like luster, cotton-like moisture conduction and wool-like warm retentiveness. As long as we pay attention to the option of makeup of blended yarn as well as processing technology, the soybean yarn can have strong competitiveness on its novelty and functions.

Vina Yang
(http://www.ccfei.net)
China Chemical Fiber Economic Information Network(CCFEI)
E-mail: yangweinan@cnfiber.com