Study On The Mechanism And Inhibition Of Cotton Fabric Yellowing Induced By Sebum/Fungi

Cotton clothing is prone to yellowing during wearing and storage,which has become a major pain point for people.This topic cooperates with Wuxi Little Swan Electric Co.,Ltd.to carry out research on the mechanism and inhibition technology of yellowing and mildew at the clothing preservation end.The yellowing substances on real clothes were explored,and the mechanism of sebum / mildew synergistic yellowing of cotton fabrics was clarified,and then the effective yellowing inhibition technology of cotton fabrics was developed.Firstly,the substances on yellowed textiles were detected by GC-MS.Daily yellowing textiles such as yellowing clothes,yellowing pillow cases,yellowing cushions and yellowing pillow cores collected from all over the country were detected by headspace-gas chromatography-mass spectrometry and solvent extraction-gas chromatography-mass spectrometry,and the differences in the composition of different yellowing textiles were analyzed.The test results were summarized and the yellow substances with a content greater than 3 % were screened.Seven yellowing substances on yellowing textiles were identified as palmitoleic acid,myristic acid,decanal,squalene,nonanal,methyl heptenone and geranyl acetone.The yellowing substances detected from clothing,methyl heptenone,geranyl acetone and palmitoleic acid were tested for yellowing pollution of cotton fabrics.With the sample yellowness coefficient as the index,the visual yellowing degree of the sample was standardized.The results showed that three kinds of yellowing substances had yellowing effect on cotton fabrics,and geranyl acetone had the most significant yellowing effect.Then,the isolation and identification of dominant colonies on yellowing clothing were carried out.The yellowing and mildew cotton clothes collected from Beijing,Shanghai,Jiangsu and Henan were collected for the extraction,separation and purification of mold colonies.The obtained strains were subjected to morphological observation,18 S r DNA-ITS sequence analysis and homology comparison.The types and dominant fungi of mold on yellowing clothes in 4 regions were identified.The results showed that the dominant fungal genera on yellowish clothing in Henan were Penicillium and Aspergillus,the dominant fungal genera on yellowish clothing in Beijing were Penicillium,and the dominant fungal genera on yellowish clothing in Jiangsu and Shanghai were Aspergillus.In order to explore the mechanism of sebum /mold synergistic yellowing of cotton clothing,four kinds of yellowing fungi were screened according to the color and characteristics of molds,which were Aspergillus chevalieri,Epicoccus niger,Phoma sp.and Penicillium citrinum.The results these four molds could aggravate the yellowing of cotton fabrics to a certain extent,and the yellowing effect of oleic acid combined with Phoma sp.was better than that of the other three molds.The cotton fabric contaminated by oleic acid combined with stem mold was detected by GC-MS,and the yellow substances on it were palmitic acid,azelaic acid,myristic acid and nonanal.According to the results,the yellowing mechanism of cotton fabric induced by oleic acid and Phomopsis stem was analyzed.Finally,the dominant fungi extracted from yellowing clothes in 4 areas were studied.Three kinds of bacteriostatic agents,methyl sorbate,sodium benzoate and zinc sulfate,were used to inhibit the dominant molds on cotton fabrics.The optimal bacteriostatic concentrations of three bacteriostatic agents against single mold and mixed mold on cotton fabrics were determined.The results showed that when the addition amount of potassium sorbate and zinc sulfate was 0.12 g / 100 m L and the addition amount of sodium benzoate was 0.14 g / 100 m L,it was the best antibacterial concentration of mixed dominant molds on cotton fabrics.The inhibition effect of low concentration ozone on cotton fabric yellowing was studied.The response surface method was used to optimize the low concentration ozone concentration,release time and ozone treatment time interval,and the mildew grade of cotton fabric was used as the evaluation index.The results show that when the ozone concentration is 8 ppm,the release time is 8 min,and the treatment time interval is 5 d,it is the best solution.The cotton fabric treated under this condition has no mold growth and the yellowness of the treated cotton fabric is greatly reduced compared with the yellowness of the mildewed cotton fabric.