Study On The Application Of Natural Dyes In Cotton Fabric Dyeing

Natural dyes are non-toxic and harmless to human body,the colour of dyed fabrics is natural and soft,have excellent antibacterial and anti-ultraviolet properties,and have good biodegradability and environmental compatibility.Now,they gradually attract people's attention.This paper is aimed at the problem that it is difficult to dye cotton fabrics with natural dyes and the color fastness of dyed fabrics.Chitosan is used as raw material to prepare cationic modifiers,and cationic modification of cotton fabrics is carried out to explore the dyeing of modified cotton fabrics with natural dyes.The process,and studied the synergistic effect of mordant and cationic modifier to improve the color fastness of dyed fabrics.Based on the substitution degree of chitosan quaternary ammonium salt,the technological factors of chitosan and 2,3-epoxypropyltrimethylammonium chloride as raw materials for the synthesis of chitosan quaternary ammonium salt were studied.The optimum process was as follows:reactiontemperature The mass ratio of chitosan to 2,3-epoxypropyltrimethylammonium chloride was 1:4 at 90? for 5 h.The process for the modification of cotton fabric with chitosan quaternary ammonium salt is:modifier 7g/L,temperature 90?,time 80 min.The dyeing process of modified cotton fabric with different kinds of natural dyes was studied by taking the color characteristic value and apparent color depth as the indexes.The optimal dyeing process of each dye was determined and the fastness of dyed cotton fabric was studied.The process for dyeing modified cotton fabric with chestnut shell pigment:temperature 90?,time 50 min,the dye has better lifting on the modified cotton fabric,the dyeing fabric has poor light fastness,washing and rubbing fastness are good.The process for dyeing modified cotton fabric with impatiens pigment:temperature 90?,time 60 min,the dye has better lifting on the modified cotton fabric,the dyeing fabric has poor light fastness,washing and rubbing fastness are good.The process for dyeing modified cotton fabric with safflower yellow pigment:temperature90?,time50 min,the dye has better lifting on the modified cotton fabric,the light fastness of the dyed fabric is poor,washing and rubbing fastness are good.The process for dyeing cotton fabric with tea tree fruit pigment:temperature 85?,time60 min,better lifting on modified cotton fabric,poor light fastness of dyed fabric,washing and rubbing fastness are good.The process for dyeing modified cotton fabric with pomegranate skin pigment:temperature90?,time60 min,the lifting property on the modified cotton fabric is generally good,the fastness of dyed fabric is good.The process for dyeing modified cotton fabrics with yarrow pigment:temperature90?,time50 min,better lifting on modified cotton fabrics,light fastness of dyed fabric is general,discoloration in soaping fastness is low and the rubbing fastness is good.The mordant aluminum sulfate,ferrous sulfate,ferric chloride and chitosan quaternary ammonium cotton fabric were used to study the method of improving the color fastness of dyed cotton fabric.The results showed that the mordant and chitosan quaternary ammonium salt After treatment,the K/S value and color fastness of dyed fabrics are improved.Under the mordant/modification/dyeing process,the light fastness of chestnut shell dyed fabric can be improved by 1-2 grades,pomegranate pigment and The light fastness of yarrow color dyed fabric can be increased by 2-3 grades;under the modification/dyeing/mord dyeing process,the glare yellow dyed fabric can be improved by 3 grades.