The Investigation Of Variation Cashmere Fibers With Raman Spectrum

Cashmere, which is known as "soft gold", is a high quality raw material for textile industry. The production of wool and cashmere in China is ranking first in the world. China is a big country for cashmere production and processing. In recent years, for the influencing of breeding methods, climate and other factors, the cashmere fiber begins variation. It not only brings a certain impact on industry but also gives new opportunities. In this paper, we use Raman spectroscopy to characterize the variation of cashmere fiber. On the one hand, we view Raman spectroscopy as the standard for the studying of surface treatment technology and then, we evaluate technological parameters. On the other hand, we use Raman spectrum characterize the secondary protein structure.For the Study of variation cashmere fibers’ surface processing, we design two kinds of surface treatment processes, and then we use Raman spectroscopy analyzing the technological parameters: for the traditional wool washing process, It mainly analyses the wetting temperature and baking time. Results indicate that, the best wool wetting temperature is 60℃, the baking time is 25-30 min. About the organic solvent scouring process, it discusses the type of solvent, soaking temperature, soaking time. It turned out that, the variation cashmere fiber is soaked in diethyl ether/aqueous organic solvent in the optimal condition. The optimal soaking time for the wool/dimorphic fibers and the second-fine/cashmere fibers are about 16-22 minutes and 6-12 minutes, respectively. The optimal temperature for the wool/cashmere/second-fine fibers and the dimorphic fibers are about 20-30℃, and 15-20℃, respectively.We use Raman spectra compare the two kinds of scouring processes. The results show that the diethyl ether/aqueous organic solvent is better than the conventional scouring process.The Raman spectrum is used to analyze the surface layer and the inner layer of variation cashmere fibers for characterizing the protein secondary structure. The amino acid amount of cashmere fibers is higher than the wool fibers. The performance of cystine decides the stability of surface scale layer. The amount of cystine increases with wool, dimorphic, second-fine, cashmere fibers. The stability of the scales also showed an increasing trend. For spiral structure, the second-fine and dimorphic fibers internal helical conformation content are higher than the surface. Wool and cashmere fibers are on the contrary. So we consider helical conformation as the performance index of the variation cashmere fibers.This paper is a basic research work for variation cashmere fibers by Raman spectroscopy. It can provide a theoretical basis for further exploration of dyeing, shrink proof properties in variation cashmere fibers.Innovation points:1 The characterization of protein secondary structure for variation cashmere fiber’s surface and internal.2 The cashmere is longitudinal incised from the inside.