Study On The Point-shaped Anti-wrinkle Finishing Technology And Performance Of Cotton Fabrics Modified By Citric Aci

Cotton fabric has excellent properties such as skin-friendliness,moisture absorption,breathability,comfortable wearing,etc.It is a popular textile for consumers of different ages.However,pure cotton fabric also has the disadvantage of poor wrinkle resistance,which affects the use experience.The research on crease-resistant finishing of cotton fabric has a history of nearly one hundred years,and great progress has been made in crease-resistant finishing agent and process.Pure cotton fabrics get good wrinkle resistance,but at the same time,its strength often drops,which has not been effectively solved for many years,seriously affecting the service life of wrinkleresistant finished cotton fabrics.Therefore,it is of great significance to study the improvement of strength loss of pure cotton fabric after crease-resistant finishing.At present,commonly used anti-wrinkle finishing agents for cotton fabrics include synthetic resin anti-wrinkle finishing agents containing formaldehyde,and formaldehyde-free anti-wrinkle finishing agents such as polycarboxylic acid,dialdehyde and reactive silicone.In this paper,the anti-wrinkle finishing agent based on formaldehyde-free,cheap,easy-to-obtain and non-toxic citric acid is used to finish the anti-wrinkle finishing of cotton fabric by chemical modification combined with spot anti-wrinkle finishing process.Firstly,the strength loss source of citric acid crease-resistant cotton fabric was analyzed by Na OH.The results show that the strength loss caused by cross-linking and non-cross-linking(combined action of acid and heat)is close to 1: 1.On this basis,citric acid crease-resistant finishing solution is improved by using citric acid,ammonium citrate and low alcohol.Under the optimal conditions,the total crease recovery angle of treated cotton fabric is close to that of citric acid crease-resistant finished cotton fabric,but the strength retention rate is increased by more than 20%.The cotton fabric treated with modified citric acid was analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM)and Fourier transform infrared spectroscopy(FT-IR).The results showed that the cotton fabric treated with modified citric acid had less surface damage,high crystallinity and high degree of esterification with citric acid,which was consistent with the macroscopic results of wrinkle recovery angle and breaking strength retention.The cotton fabric treated with modified citric acid can have both wrinkle recovery performance and breaking strength retention rate,but there is still a gap of about 10 degrees between the total wrinkle recovery angle of the cotton fabric treated with citric acid,which cannot be effectively improved after many improvements.On the basis of chemical crease-resistant finishing,continue to study how to improve the strength retention rate of crease-resistant finished cotton fabric by physical means.The micro and macro stress analysis of wrinkle-resistant finishing fabric shows that the partial cross-linking and partial non-cross-linking wrinkle-resistant finishing can improve the strength retention rate of fabric.Based on the analysis of plane stress concentration,the anti-wrinkle finishing pattern that can be used for cotton fabric is analyzed by ANSYS.The results show that the circular pattern can effectively avoid stress concentration.Through the cooperation of anti-wrinkle finishing part and non-finishing part,the antiwrinkle effect can be ensured and the strength retention rate can be improved.On the basis of determining the circular pattern,the parameters such as paste dosage,missing printing rate,circular pattern size,weight gain under the same size were optimized.The results showed that under the optimal process,and with the same wrinkle recovery performance as padding crease-resistant finishing fabric,the breaking strength retention rate of the dot crease-resistant finishing cotton fabric could be increased by about 25%.Using different cloth samples and different crease-resistant finishing agents could reproduce good experimental results,and the moisture absorption and air permeability of the fabric after crease-resistant finishing were improved.It can be seen that dot crease-resistant finishing of cotton fabric has certain universality and good application prospect.