The Construction Of Micro-dissolution System And Its Research On Reducing The Hairiness Of Cotton And Linen Blended Products

Yarn hairiness,which plays an important role in yarn and fabric processing,is a key index to describe the quality of a yarn,particularly for cotton/hemp blends.In the past,methods such as process optimization,optimization of raw material selection,and equipment modifications were adopted to reduce yarn hairiness.However,hairiness could be reduced but could not be removed using these methods.While singeing can remove yarn hairiness to some extent,it requires strict control of temperature.Up to now.there was no report on reducing hairiness via chemical methods.In this paper,NaOH and LiCl/DMAc solution was selected as dissolution system to reduce yarn hairiness.The process was optimized through single factor and orthogonalanalysis.using reduction of yarn hairiness,yarn breaking strength and elongation at break as indicator.The optimum process was as follows:the sample was first activated for 45min at 65℃ using 150g/L NaOH,and then the activated fabric was treated for 120min at 65℃ using100g/L LiCl/DMAc.Finally,morphological and crystalline structure and thermal behavior of treated fibers were studied by scanning electron microscopy(SEM),X-ray diffraction(XRD),Infrared spectroscopy(IR)and Differential scanning calorimetry(DSC).It was found that hemp fiber was partially dissolved in dissolution system,while cotton fiber was essentially unchanged.Additionally.XRD,IR and DSC pointed that the degree of crystallinity of hemp was reduced after treatment by dissolution system.Cotton and hemp were blended with different ratios and twist levels in spinning process to study their effects on hairiness of the blended yarn.The results indicated that hairiness of blended yarn increased with increased hemp content while hairiness of blended yarn was reduced with increasing twist.Obviously,hairiness of blended yarn was decreased after treated with dissolution system.In addition,strength was improved,while elongation at break and yarn fineness were reduced slightly.This study also examined the effects of the dissolution system on the performance of cotton/hemp blend fabrics.The results showed that the treated fabric had higher strength and elongation was improved;the treated fabrics also showed reduced stiffness and increased softness;the fabric wrinkle resistance and drape were improved and the treated fabric had enhanced absorption capacity.In this study,KES-FB instrument was selected to assess fabric handle performance.The results showed that the fabric bending and compression properties and fullness of the fabric,were improved after treatment with the micro-dissolution system.