تاثير پارامترهاي الكتروريسي جهت توليد تخ تو خالي از الياف نانو و بررسي خواص مكانيكي آن

چكيده انگليسي :

The effects of electrospinning parameters to produce hollow nano fibres yarn and investigation of its mechanical properties Leila Javazmi l javazmi@tx iut ac ir Date of Submission 2011 Department of textile engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language Farsi Dr S Abdolkarim Hosseini hosiniir@cc iut ac irAbstractElectrospinning is a unique technology that produces polymer fibers with diameters in the range ofnanometers to a few microns using an electrically driven jet of a polymer solution or melt Electrospinningenables production of continuous Nanofibers nonwoven fabrics and functionalized composite fibers andyarns Hollow yarns have been created to improve consumer yarn properties to increase the entrapped airin the yarn and to gain a stronger yarn for weaving process before extraction the core fibers and produceweightless fabric after removing the core fibers So far hollow yarns have been produced by conventionalsystems such as friction spinning In hollow yarn spinning a PVA multifilament is used as a core in theyarn center and another fiber are wrapped on that core then the water soluble PVA is removed from theyarn structure in boiling water Until now a little research projects attempted to obtain hollow yarn byelectrospining process In a recent work Bhargava by a hollow rotating metal rod with attached hollowmetal hemisphere at one end and two different polymer solutions could electrospin a core sheath yarn More by removing the inner core yarn PVA electrospining yarn in boiling water hollow nanofiber yarncould be obtained In this study by manipulation of hemisphere location of Bhargava electrospining system and some smallchanges in set up of the pervious technique polyethylene terephthalate PET hollow nanofiber yarn wasproduced Electrospinning was done between two syringe needles then electrospun nanofibers collected onhemisphere surface and twisted by rotating the hemispherical collector In order to produce core sheathyarn a PVA multifilament yarn was fed as the core from feeder unit to take up unit by hollow metal rodthat attached to the hemispherical collector PET nanofibers were twisted onto the PVA yarn as the sheath and then core sheath yarn was drawn and collected on take up roller Hollow yarn was obtained byremoving the PVA yarn by dissolving in water at 60 C for 24 hours In order to produce an optimum hollow nanofiber yarn the covering was done six times on the core withconcentrations of 18 21 24 27 and 30 w v PET polymeric solution in TFA DCM 70 30 solventmixtures In series of experiments the applied voltage the flow rate and the yarn twist were kept constantat 10 kV 0 0526 ml h and 1851 TPM respectively In surveying the electrospining parameters observed that the thickness of sheath increased with increasingconcentrations of PET polymeric solution Results showed that in the concentration of 18 w v PETpolymeric solution in TFA DCM 70 30 solvent mixtures the efficiency of extracting the PVAmultifilament from the hollow yarn is more than 85 In surveying the strength and moduls value for PVA multifilament yarn core sheath yarns and hollowyarns results showed that the PVA multifilament yarn and the product hollow nanofiber yarn inconcentrations of 30 w v PET polymeric solution had the highest and lowest average strengthrespectively Also observes showed that PVA multifilament yarn core sheath yarns and hollow yarns didn thave any significant different on average extension In order to determine the wicking property of hollow yarns in different concentrations of polymericsolution the wicking coefficient for each hollow yarn was surveyed Results showed that the producthollow nanofiber yarn in concentration of 24 w v PET polymeric solution had the highest coefficientwicking More the regain moisture of hollow yarns were surveyed and concluded that the product hollownanofiber yarn in concentrations of 18 w v PET polymeric solution had the highest regain moisture Key Words Electro

جوزمي، ليلا

تاثير پارامترهاي الكتروريسي جهت توليد تخ تو خالي از الياف نانو و بررسي خواص مكانيكي آن

نخ مغزي- غلاف , غلظت , مويينگي , محلول پليمري PET , مولتي فيلامنت , PVA و رطوبت بازيافتي