Research On Flax’s Resistance To Low Alkalinity And Color Stripping Performance Of Recycling

A large number of waste textiles show a "geometric" growth.Now,lots of waste textiles are used for incineration,burial,charity recycling,or to make low-grade filling flocs and other simple recycling mostly.Waste textiles can not be recycled effectively,waste resources and pollute the environment.Flax fiber is one of the earliest fibers used by human beings.It is natural fibers with many excellent properties,such as moisture absorption and quick drying.Therefore,flax fiber is very popular with consumers.At present,the raw materials of flax fiber are scarce and expensive.The object of this research is to provide a method for flax fiber to be separated from the blended fabric and recycled for many times by studying the low alkali resistance and stripping resistance of flax fiber.The technological route of this research.At first,flax fiber and soluble polyester fiber are blended.Then through conventional weaving and reactive dyeing,the polyester/flax blended dyed knitted fabric is obtained.Under suitable conditions,the fabric is treated with NaOH low alkali solution,soluble polyester fiber is dissolved,and the loose flax fiber aggregation is left.After stripping and carding,the recovered flax fiber was obtained.After flax fiber treated with low alkali solution,its physical properties such as length,fineness and mechanical properties are test and analysed.Test molecular structure changes of flax fiber after low alkali treatment,such as crystallinity and orientation.The surface morphology of flax fiber before and after alkali treatment was observed by SEM.The structure and properties of flax fiber treated with NaOH solution were studied.The results showed that the effective length of flax fiber after low alkali treatment increased,the short fiber rate increased,the length uniformity raised,but with the number of alkali treatment increase,the fiber length gradually decreased,the short fiber rate decreased,the flax fiber fineness showed a decreasing trend,the breaking strength gradually decreased,the elongation at break increased.The crystal form of flax fiber is typical cellulose type I.After alkali treatment for many times,the crystal form has not changed,the crystallinity has not decreased but increased,and the orientation almost has not changed,which shows that the crystal area of flax fiber has not been damaged,and this alkali treatment will not destroy the internal structure of flax fiber,and will not cause great damage to flax fiber.After alkali treatment,the impurities and other attachments on the surface of flax fiber are obviously reduced,and the roughness is lower than that of raw flax fiber.Some impurities and other attachments are removed.With the increase of alkali treatment times,the surface of flax fiber becomes more and more smooth.To a large extent,the splitting degree of flax fiber is improved,and the fineness of flax fiber is reduced,which is beneficial to the spinning of flax fiber.In this paper,flax fiber was dyed with reactive dyes,choosing color stripping of flax fiber with hydrogen peroxide solution.In the single factor experiment,the condition of stripping was initially determined,and then the best condition of stripping was obtained by orthogonal experiment.Getting the best stripping process factor:concentration of hydrogen peroxide solution was 80 mL/L,temperature was 90℃,stripping time was 80 min.Under the best stripping condition,the flax fiber was dyed and stripped several times,and its structure and properties were tested and analyzed.The results showed that with the increase of stripping times,the effective length of flax fiber decreased gradually,the fineness decreased first and then increased,and the breaking strength decreased.With the increase of stripping times,the K/S value increased and the surface color of flax fiber deepened after recolor.In each stripping treatment,the stripping rate about 80%,and the stripping effect is good.The regenerated flax fiber after multiple stripping treatment can be dyed in dark color and stripped,and the regenerated flax fiber after stripping can be recycled by spinning and weaving.The crystal form of flax fiber is cellulose type I.After several stripping treatments,the crystal form of flax fiber does not change,but the crystallinity is significantly reduced.The above research provides a basis for the recycling of flax fiber.