Effect Of Plasma Treatment On The Antifelting And Dyeing Properties Of Wool Fabric

Wool is a typical protein fiber,which is often processed into high-end apparel fabrics.Because of the natural luster and excellent drape,they are very popular among consumers.However,wool also has inherent deficiencies.The unique scale layer on the surface makes the fabric felt and shrink due to the directional friction effect during washing.At the same time,the scale layer is also the main barrier in the dyeing process,making wool generally need to be dyed in a high temperature environment for a long time.It not only consumes a lot of energy,but also has a negative impact on the protein structure and mechanical properties of wool.In order to solve the problems of high waste,high energy consumption and high pollution caused by traditional scale-stripping methods and improve the properties of wool,this paper uses low-pressure air plasma treatment to improve antifelting,wetting and dyeing properties of wool fabrics.Firstly,the plasma treatment with different processing time and output power was selected.The effect of plasma treatment on the surface morphology and friction coefficient of wool fiber was analyzed.The weight loss rate,breaking strength,elongation at break,"machine washable" performance and style of the wool fabric before and after treatment were studied.The results showed that after the plasma treatment,the scale layer on the surface of the wool fiber was etched with some scales falling off.The friction coefficient increased,and the directional friction effect decreased.After plasma treatment,the weight loss rate increased with longer processing time and higher output power.The breaking strength and elongation at break in warp and weft directions were better than that of untreated fabric.When the output power was 200 W and the processing time was 120 s,the relaxation rate and felting shrinkage rate of the fabric had reached the "machine washable" standard stipulated by the International Wool Secretariat.The wool fabric under this condition was further subjected to a style analysis(KES),and the drape property,bulkiness and thickness became better after plasma treatment.Secondly,plasma treatment can significantly improve the wetting properties of wool fabrics.After being treated with different processing time and output power,the surface property of the wool fabric changed from hydrophobic to hydrophilic.The contact angle of untreated wool fabric was 141.6°.When the output power was 100 W and the processing time was 120 s,the contact angle was the smallest,which was 33.3°.According to the XPS results,the O1 s content and O/C ratio were the highest with the output power of 100 W and the processing time of 180 s,reaching 26.72% and 0.47,respectively.The content of C-C/C-H on the surface decreased,and the content of C-O and C=O increased significantly.At the same time,the S(VI)content after plasma treatment increased.It indicated that plasma treatment can change the element composition on the fabric surface,thereby improving the wetting performance.Thirdly,the wool fabrics before and after plasma treatment were dyed into two colors of black and ultra-black.The K/S value and color uniformity were tested to assess the dyeing properties.The results showed that plasma treatment can obviously promote the dyeing depth of wool fabrics,and the K/S values of black and ultra-black increased by 5.67% and 24.67%.The color uniformity of black wool fabric became better,while the ultra-black got worse.Finally,the aging behaviors of the plasma treatment were analyzed.During the aging process,the breaking strength and elongation at break of the wool fabric decreased slightly,and the felting shrinkage rate increased and then stabilized,but it was still better than the untreated sample.Moreover,there had a slight increase in the results of the contact angle,and the O1 s content on the surface of the wool fabric has a downward trend.The K/S values of black and ultra-black decreased by 1.52% and 4.38%.