Study On Identification Method Of The Fiber For Hair Products

Hair products are made from human hair,chemical fiber and animal hair through physical and chemical processing processes.In recent years,consumers began to pay more attention to the impact of hairstyle on personal image.As a result,more modern people prefer wigs with easy-care,changeable shape,and convenient wearing,which has prompted the Chinese hair products industry to enter a period of rapid development.Now China has become the global distribution center of raw materials for hair products and the largest producer and exporter of hair products.However,due to the lack of raw materials,the price of hair products made from human hair is high.To make profits with increases in the demand for high-end products,counterfeit human hair wigs mixed with animal hair or chemical fiber have appeared in the market,which seriously affected the development of the hair products industry.Hair products have a good market prospect,but currently,the research on the identification standard for hair product fiber is still in the primary stage.The lack of standards leads to confusion in the quality management of the hair products industry.Therefore,the study on qualitative identification standards for hair products is needed for standardizing the industry development and related to the interests of consumers and enterprises.A good standard is needed to provide the technical support for more healthy industry development.This paper studied the macro morphology,microstructure and physical and chemical properties of human hair wigs,animal hair wigs and chemical fiber wigs.Meanwhile,we investigated the feasibility of applying microscopy and spectral technology to identify hair products.Moreover,we set a method to identify hair product fiber,which is rapid,accurate and nondestructive,and we formed a standard based on the method.The specific conclusions are as follows:（1）The basic properties of human hair wigs,animal hair wigs and chemical fiber wigs were researched by handle-visual method,stretching method,combustion method,chemical dissolution method,infrared spectroscopy and X-ray diffraction（XRD）.The macro morphology of human hair wigs,animal hair wigs and chemical fiber wigs is relatively similar.The mechanical properties,combustion properties,dissolution properties and infrared spectrum of chemical fiber wigs are different from human hair wigs and animal hair wigs,which can be effectively identified.However,the mechanical properties,combustion properties,dissolution properties and infrared spectrum of human hair and animal hair wigs,especially human hair and yak hair wigs,are not significantly different.So,it is impossible to identify them by the methods mentioned above.The crystallinity of human hair wigs measured by XRD is about 28%,which is different from that of yak hair wigs with an average of 34%.The diffraction peaks of the XRD for PET wigs and PVC wigs are different when the diffraction angle is between 20°-30°,and it is also different from the XRD of animal hair wigs.The XRD method can be used to identify the fiber of wigs.（2）When we observed the cross-section of human hair wigs and yak hair wigs by a scanning electron microscope（SEM）,it was found that the shape of their cross-section was circular or oval similarly,but with different diameters.The proportion of fibers containing the medullary cavity in human hair wigs is between 30%-75%,with an average of 58.8%.The proportion of fibers containing medullary cavity in yak hair wig fiber is less than that in human hair wig,with an average of 11.4%.Therefore,it is feasible to take the proportion of the medullary cavity as the identification method.The morphology of the medullary cavity of human hair wigs and yak hair wigs was observed by a polarizing microscope.It was found that the content of the medullary cavity of yak hair wigs was significantly less than that of human hair wigs.Also,the morphology of the medullary cavity was significantly different between them.The birefringence of human hair wig fiber measured by a polarizing microscope is between 0.005-0.008,with an average of 0.007.The birefringence of yak hair wig fiber is between 0.008-0.012,with an average of 0.010.Human hair wigs and yak hair wigs can be distinguished by exploiting the difference in their medullary cavity content and shape and their birefringence.（3）The near-infrared spectra of human hair wigs,animal hair wigs and chemical fiber wigs were collected by Fourier transform near-infrared spectrometer.Then the spectra are preprocessed by the standard normal variable transformation + second derivative + Norris derivative filter.The principal component analysis is used to reduce the dimension of the spectra data.Combined with the Mahalanobis distance discriminant analysis,the discriminant model for the identification of wig fibers is established.The accuracy of the model was verified by internal and external validation sample sets.The results showed that the identification accuracy of the model for human hair wigs,animal hair wigs and chemical fiber wigs reached 100%,which can realize the rapid,accurate and nondestructive identification of hair products.