Extraction Of Natural Dye And Its Application On Cotton Fabric

With the progress of society and the improvement of living standard,people's requirements for textile quality are increasing day by day.Natural dye has attracted extensively attention because of its excellent quality of natural environmental protection.Especially its anti-ultraviolet and anti-bacterial effect which bring unprecedented development opportunities for its textile applications.In this paper,three kinds of plants were selected to study.Their suitable extraction method,cotton fabric modifying and dyeing method,and the color fastness,anti-ultraviolet,anti-bacterial effect and washing resistance of dyed cotton fabric were tested.The optimal extraction conditions were as follows:50%ethanol as extraction solvent,the ratio of solid to liquid was 1?18,extracted at 50?with 90 min.Under this process,the extraction rate of natural dyestuff was 17.85%.The natural dye solution of viola philippic has good stability and good thermal stability at p H=2-8.The cotton fabric was modified with adsorbent modifier 18,and then dyed with viola philippic natural dye.The dyeing fastness could meet the clothing requirements,with washing fastness of grade 3 level,rubbing fastness of grade 4 level,and light fastness of grade 3 level.The optimum modification process was as follows:modifier 18 6 g/L,modified at 30?with 20 min,bath ratio of 1?50.The suitable dyeing process was as follows:natural dye viola philippic 20 g/L,Fe SO₄ 2%,CA 0.5 g/L,p H value was 6,90?for 50 min.The UPF value of dyed cotton fabric was 184.51,after 20 times of laundering UPF was 153.11,which had excellent anti-ultraviolet effect.The dyed cotton fabric had good antibacterial effect,and the antibacterial rates against E.coli and S.aureus were 77.03%and 73.88%,respectively.After laundering 10 times,the antibacterial rates against E.coli and S.aureus were 61.22%and 59.58%,respectively.Dyed samples had good durability.The natural dye was extracted from Cnidium monnieri(L.)Cuss.The optimum extraction conditions were as follows:60%ethanol was used as the extraction solvent,and the ratio of solid to liquid was 1?15 at 70?for 90 min.Under this process,the extraction rate of natural dye from Cnidium monnieri(L.)Cuss was 10.80%.The natural dye solution has good acid stability at p H 2-8 and good thermal stability.The cotton fabric was modified with adsorption modifier JY-1,and then dyed with Cnidium monnieri(L.)Cuss natural dye.The color fastness of the fabric needed to be further improved.The suitable modification process was as follows:JY-1 5g/L,acetic acid 2%,2 times padding,pick up rate was 85%,pre-drying at 100?for 3 min,baking at 150?for 2 min.Direct dyeing method was used,and the suitable dyeing process was as follows:natural dye 10 g/L,p H was 4 at 80?for 60 min.The washing fastness can be improved from 2 to 3,dry rubbing fastness from 2-3 to 3 and wet rubbing fastness from 2 to 3 after mordant dyeing with Fe SO₄.The fixing agent O further improved the dry rubbing fastness to 3-4 and the wet rubbing fastness to 3-4.The color fastness of the dyed fabric could meet the requirements.The UPF value of dyed cotton fabric was 242.60 and 140.11 after 20 times washing,which has excellent anti-ultraviolet effect.The dyed cotton fabric had good antibacterial effect,and the antibacterial rate to E.coli and S.aureus were 89.63%and 93.19%,respectively.After washing for 10 times,the antibacterial rate to E.coli and S.aureus were 86.21%and90.18%,respectively.Dyed samples had good durability.The optimal extraction process was as follows:50%ethanol was used as the extraction solvent,and the ratio of solid to liquid was 1?12,at 100?for 60 min.Under this process,the extraction rate of natural dyestuff from Solidago canadensis L was 18.10%.Solidago canadensis L natural dye solution at p H=3-7 conditions had good stability,thermal stability was poor.The cotton fabric was modified with reactive modifier SH,and then dyed with natural dye.The color fastness of dyed fabric needed to be further improved.The optimum modification process was as follows:SH 20 g/L,Na OH 10 g/L,80?for 40 min,bath ratio 1?50.The optimum dyeing process was as follows:natural dye 20 g/L,KAl(SO₄)2%,p H 7 at 80?for60 min.Color fixing agent O would improve wash fastness from 2-3 to 3,dry rubbing fastness from 3-4 to 4,wet rubbing fastness was still 3-4,and light fastness from 2-3to 3.The color fastness of the dyed fabric could meet the requirements.The UPF value of dyed cotton fabric was 206.59 and 204.76 after 20 washes,shown excellent anti-ultraviolet effect.The dyed cotton fabric had good antibacterial effect,and the antibacterial rate to E.coli and S.aureus were 86.23%and 88.71%,respectively.After washing for 10 times,the antibacterial rate to E.coli and S.aureus were 83.66%and85.71%,respectively.Dyed sample had good durability.