Preparation Of Red Natural Dye And Its Application In Cotton Knitted Fabric

As the world is increasingly concerned about environmental issues,ecology,environmental protection,sustainable development have become the themes of social development.Natural dyes are taken from nature,safe and non-toxic,they can increase the use of natural resources and reduce dependence on petrochemical resources.At present,the research of natural dyes mainly focuses on the research of plant dyes.The fabric dyed with plant dyes has the obvious defect of low light fastness.How to find natural dyes with better light fastness is a research hotspot.This subject explored the preparation and application of innovative natural dyes through the preparation and application of iron oxide red mineral dyes,the mineralization of madder plant dyes,and the application process on fabrics.In this paper,the iron oxide red dye was wet ground,the best grinding process was discussed,and the cationic modified cotton knitted fabric was pad dyed,the modification process and pad dyeing process were optimized.According to the properties of rubia dye,rubia plant mineral dye was prepared by first chelating rubia powder dye with aluminum potassium sulfate,and discussed the best preparation process,then the cationic modified cotton knitted fabric was pad dyed and optimized the pad dyeing process.The dispersing agent with better dispersibility was selected to wet grind the iron oxide red powder with larger particle size by high-speed sand mill.The effects of grinding medium,grinding speed and time on the dye were mainly considered.The results show that the best preparation process of iron oxide red mineral dye is as follows: 6g iron oxide red powder,50 g of 0.8mm:0.6mm zirconium beads with a mass ratio of 1:4,60 g distilled water,2g dispersant added twice,grinding at 4000 rpm for 8h.The grinding dynamic was studied.The particle size of the dye is 665 nm,and it can be stored for 95 days.Pure cotton knitted fabric was modified with BS cationic modifier.The influence of relevant factors on the modification was discussed.The optimized modification process was obtained as follows: BS 10%(omf),bath ratio 1:30,modified at 80? for 30 minutes.The mineral dye was used to modify the pure cotton knitted fabric.Through single factor experiment,the influence of dye dosage and other effects on dyeing was investigated,.The dyeing process was optimized by considering the K/S value,colour fastness of the dyed fabric.The optimized pad dyeing process is as follows: mineral dye 40g/L,binder 50g/L,anti migration agent 15g/L,2-dip-2-nip,pick up 70%,pre-drying at 90? for 80 s,baking at 150? for120 s.The results show that the K/S value of the dyed fabric is 1.542,the dry rubbing fastness of dyed fabrics reached level 4,the wet rubbing fastness reached level 3-4,the fastness of soap discoloration reached level3,the staining fastness reached level 4-5,and the light fastness reached level 5.In the wet,friction environment,the fastness is slightly poor,but is resistant to sunlight and hard to fade.The rubia plant mineral dyes were prepared by studying the properties of powdered madder plant dyes,including heat stability,color acid-base stability,and antibacterial properties.It was found that the rubia plant mineral dye prepared at p H 5 and 80? has good properties in all aspects.By investigating the effects of the amount of sodium alginate and urea in pad dyeing solution,baking temperature and time on the L,a,b,K/S value,color fastness and handle of dyed fabric,the optimal pad dyeing process was obtained as follows: 30g/L Rubia plant mineral dye,5g/L of2% sodium alginate and 5g/L of urea,2-dip-2-nip,pick up 70%,pre-drying at 90? for 120 s,baking at 120? for 180 s.The K/S value of the fabric is2.6839,the dry rubbing fastness of dyed fabrics reached level 3-4,the wet rubbing fastness reached level 3-4,the fastness of soap discoloration reached level 3,the staining fastness reached level 4-5,and the light fastness reached level 3-4.The fastness was better than the one dip-dyed.The anti-ultraviolet property of the dyed fabric is better than that of the non-dyed fabric.The dyed fabric has certain inhibition ability to the three kinds of bacteria,and is stronger than the one without mordant.