| In view of the practical demand of enterprises of camel wool textile,this study focused on the function of self-regulating of the fabric with poor thermal buffer performance.The research process are as follows:nanometer microencapsulation of phase change materials(PCMs)was used as functional carrier.The polyacrylonitrile(PAN)nanofiber yarn was spun with PCMs.The PAN nanofiber yarn was used as the core yarn and the camel fiber as the covering layer to make the core-spun yarn.Firstly,considering the comfortable temperature of human body in winter,tetradecane(core material)and melamine formaldehyde(shell material)was selected,and the microencapsulation experiment was carried out by in-situ polymerization method.By the cooperation of emulsifier and high-speed stirring,thetetradecane was broken into tiny oil particles in the water system to form the water-oil interface.With the dripping of melamine formaldehyde,the system was adjusted to an acidic environment to promote polycondensation of melamine formaldehyde on the interface.With the progress of the experiment,the melamine formaldehyde was deposited to the polymer shell,and the tetradecane was finally encapsulated.In the preliminary study,it was found that the image of samples showed different results with heat-storage test(DSC).In the support of pyrolysis(TG)data,the unencapsulated PCMs in microcapsule samples were discussed,and the contents of unencapsulated PCMs were excluded by weight loss comparison.After eliminating the quality interference of the invalid mat erials,the optimized formula for calculating the encapsulation rate was obtained,and the samples were reprepared.Finally,the optimal preparation conditions of the nanometer phase change microcapsule were obtained:p H=4.5,the initial temperature was 75?.The phase change microcapsules were spherical with the enthalpy value of 120J/g,the encapsulation efficiency of 81.4%,the phase transition temperature ranges was from 15?to 30?,the peak value was about 25?.Secondly,nanometer phase change microcapsules were mixed with polyacrylonitrile spinning solution for electrostatic spinning.Since the ring spinning machine required the mechanical properties of the core yarn in the subsequent experimental design,the influence of spinning liquid concentration,voltage,twister speed and the addition of microcapsule was mainly investigated.After the experiment,it was found that the parameters directly affect each other.Considering the fineness of yarn,the spinning solution concentration of 12%was set as the origin and the experiment was carried out.The final results showed that the best parameters are as follows:the concentration of the spinning solution was 12%,the voltage was±9k V,the infusion volume was 1ml/h,the twister speed was 300r/min,the winding speed was 100r/min.The yarn showed the best strength when the amount of phase change microcapsule was 7.5%,the fracture strength was 29.7m Pa and the elongation at break was 20.9%.Finally,the obtained nanofiber yarn containing PCMs was used as the core yarn and the camel fiber as the cortex to spin the core-spun yarn and woven into the double-thread fabric.Because of the difficulty of spinning camel core-spun yarn,the instrument parameters were adjusted.The main parameters were:z-twist,the roller center was 47mm,the program diameter was 45mm,the roller front punch was 2.5mm,the roller pressure was 140·100·140N,the draft transformation gear was 48/71,the twist gear was 41/79.Under this parameter,the effects of twist factor,camel wool ratio,back draft on yarn cladding performance and strength were investigated.Since the proportion of camel fiber was inversely proportional to the content of PCMs in the core-spun yarn,the proportion of camel hair fiber was controlled.Finally,the production parameters were determined as follows:the proportion of camel fiber was 30%,the twist coefficient was 550,the back draft was 1.35.The basic energies of the core-spun yarn were as follows:the breaking strength was 462.3c N,the breaking elongation was 23.6%,the hairiness index was 69.88,the dry irregularity was 29.06%,the linear density was 23.26 Tex,the moisture regain was 6.07%.The core-spun yarn was woven and tested:the breaking strength was 2226.33c N,the bending stiffness was 0.0600/0.0998,the pilling grade level was 2,the average thickness was 1.27 mm,the grams weighs was 150.6 g/m2,the ventilation volume was 16.89 L/ms,the crow value was 92clo/oz,the heat preservation rate was4.97%,the enthalpy value was 5.73 J/g,the melting peak was 24.87?,the heat conduction coefficient was 120.41W·m-2·K-1. |
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