Study On The Surface Modification Of Low-temperature Plasma On Variational Cashmere Fibre

The cashmere is a rare and precious special animal fibre, which is welcomed by people from each country. Global climate warming, variety improvement, breeding mode and other factors, which resulted in the variation of physical and chemical properties in recent years. It brought enormous negative factors to the development of cashmere industry. This paper focused on the study of difference of various types of cashmere fibre’surface properties by air-low-temperature plasma before and after treatment, mainly in order to explore a reasonable and superior air-low-temperature plasma treatment condition, and the cashmere products can significantly increased its utilitarian and added value.Through establishing the single factor and orthogonal experiment, the44#cashmere fibre comes from the tenth area was treated by air low temperature glow discharge in the trials. The surface properties were researched under different treating time, cabinet pressure and discharge power conditions. The friction, tensile and infiltrating index were tested before and after plasma treating. After comprehensive evaluation of treatment, the optimized air-low-temperature plasma treatment condition is as follows:the cabinet pressure is10Pa, discharge power is70W and the treating time is150s. After the treatment of optimized condition, the breaking strength and breaking elongation of various types of fibre from different areas loss little, remained unchanged. The inverse scale coefficient of friction of various types of fibre from different areas is larger than shun scale coefficient of friction. After plasma treatment, the friction coefficient has increased to different extents, but the friction effect has decreased.The scanning electronic microscope(SEM) was used to observe the subtle changes in the surface structure of pure cashmere and long fibre before and after treatment. Different conditions revealed the damage of scale structure of cashmere. The intense treatment condition brought strong damage, and the touch-feeling of treated fibre will be rough slightly.Using X-ray photoelectron spectroscopy(XPS) to analyze surface of pure cashmere and long fibre, the results showed that the surface elemental composition and elemental ratio changed after different conditions of air-low-temperature plasma treatment. As to pure cashmere, the surface content of C reduced relatively, the untreated and treated fibre is72.20%and67.34%respectively, the content of O and N increased in different degree, the ratio of O/C and N/C increased as well. O/C of untreated and treated is27.69%and37.57%, N/C of untreated and treated is8.24%and9.73%respectively.As to long fibre, the surface content of C and O increased relatively, the content of N decreased, the ratio of O/C of untreated and treated is28.13%and31.20%respectively,the ratio of N/C of untreated and treated is9.06%and6.17%respectively.The surface oxygen polar group of pure cashmere and long fibre increased, which makes the infiltrating property enhanced remarkably.There are some differences of each element relative percentage between pure cashmere and long fibre.Finally, this paper also studied the time effect of capillary effect of cashmere strands with air-low-temperature plasma treatment. The results indicated that purple strands have better capillary effect than blue strands. The two strand curve’change was very similar, and the effective surface modification period was about4to5days. In order to avoid degradation, the modificatory material must make other treatment within the period to maintain its modification effect.