纺黏非织造布工艺参数对纤维直径的影响

对有关纺黏工艺参数对纤维直径的影响进行了仿真实验和讨论,对不同的工艺参数进行了数值模拟,并对聚合物细流的最终直径进行了实测,发现聚合物挤出量越小,聚合物熔体温度越大,气流初始温度越高,气流初始速度越大时,越有利于聚合物熔体的气流牵伸,纤维直径越小;实验结果显示:测试结果与模型预测值十分吻合。本研究也显示了在对纺黏非织造布工艺和设备进行计算机辅助设计方面具有较好的应用前景     

Effects of parameters on nanofiber diameter determined from electrospinning model

In this paper the effects of 13 material and operating parameters on electrospun fiber diameters are determined by varying the parameter values in an electrospinning theoretical model. The complexity of the electrospinning process makes empirical determination of the effects of parameters very difficult. The results show that the five parameters (volumetric charge density, distance from nozzle to collector, initial jet/orifice radius, relaxation time, and viscosity) have the most significant effect on the jet radius. The other parameters (initial polymer concentration, solution density, electric potential, perturbation frequency, and solvent vapor pressure) have moderate effects on the jet radius. Parameters relative humidity, surface tension, and vapor diffusivity have minor effects on the jet radius. Knowing the relative effects of parameters on jet radius should be useful for process control and prediction of electrospun fiber production.     

The influence of electrospinning parameters on the structural morphology and diameter of electrospun nanofibers

Electrospinning is a simple method of producing nanofibers by introducing electric field into the polymer solutions. We report an experimental investigation on the influence of processing parameters and solution properties on the structural morphology and average fiber diameter of electrospun poly ethylene oxide (PEO) polymer solution. Experimental trials have been conducted to investigate the effect of solution parameters, such as concentration, molecular weight, addition of polyelectrolyte in PEO solution, solvent effect, as well as governing parameter, such as applied voltage. The concentration of the aqueous PEO solution has shown noteworthy influence on the fiber diameter and structural morphology of electrospun nanofibers. At lower concentrations of PEO polymer solution, the fibers showed irregular morphology with large variations in fiber diameter, whereas at higher concentrations, the nanofibers with regular morphology and on average uniform fiber diameter were obtained. We find that the addition of polyelectrolytes, such as sodium salt of Poly acrylic acid (PAA) and Poly allylamine hydrochloride (PAH), increases the conductivity of PEO solutions and thereby decreases the bead formation in electrospun nanofibers. The increase in applied voltage has been found to affect the structural morphology of nanofiber while the addition of ethanol in PEO solution diminishes the bead defects. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

静电纺丝工艺对二醋酸纤维素纳米纤维形貌及直径的影响

以质量比为2∶1的丙酮/N,N-二甲基乙酰胺混合溶液为溶剂配制二醋酸纤维素(CA)溶液,采用静电纺丝制备CA纳米纤维,探讨了CA浓度、纺丝电压、接收距离和溶液推进速度等工艺条件对CA纳米纤维形貌、直径及其分布的影响。结果表明:CA纳米纤维的直径随CA浓度增加而增大,随纺丝电压增大而减小;适当的接收距离和溶液推进速度可以获得直径较小且分布均匀的纤维;当CA质量分数为11%、纺丝电压为30 k V、接收距离为15 cm、溶液推进速度为0.010 m L/min时,纺丝效果好,纤维平均直径约130 nm,且直径分布较均匀。     

Correlating the 3D melt electrospun polycaprolactone fiber diameter and process parameters using neural networks

In the present work, we developed an artificial neural networks (ANN) model to predict and analyze the polycaprolactone fiber diameter as a function of 3D melt electrospinning process parameters. A total of 35 datasets having various combinations of electrospinning writing process variables (collector speed, tip to nozzle distance, applied pressure, and voltage) and resultant fiber diameter were considered for model development. The designed stand-alone ANN software extracts relationships between the process variables and fiber diameter in a 3D melt electrospinning system. The developed model could predict the fiber diameter with reasonable accuracy for both train (28) and test (7) datasets. The relative index of importance revealed the significance of process variables on the fiber diameter. Virtual melt spinning system with the mean values of the process variables identifies the quantitative relationship between the fiber diameter and process variables.     

断裂纤维及工艺对纺粘法PP纤维直径的影响

采用弹性球-弹性杆的纤维运动模型,建立了纺粘法生产断裂纤维的运动方程;通过计算机数值模拟的方法分析了工艺参数对聚丙烯(PP)纤维直径的影响。实验表明,根据断裂纤维运动模型和方程预测的PP纤维直径与实测值吻合;聚合物挤出量越小,熔体温度越高,骤冷压力、气流初始温度和吸风速度越大,文丘里间隙适中时,纤维直径越小,有利于提高成网质量。     

纺粘工艺参数和牵伸器设计几何参数对纤维直径的影响

建立了纺粘聚合物气流牵伸模型,采用计算机数值模拟方法求解牵伸器的喷射流场,分析了纺粘工艺参数和牵伸器设计几何参数对纤维直径的影响,得出了影响规律。     

Electric current as a control variable in the electrospinning process

In the electrospinning process submicron‐diameter polymer fibers can be produced when a high potential difference is applied to a polymer drop suspended at the tip of a capillary. The electrospinning process is affected by a wide range of parameters, because of which controlling the properties of the fibers is difficult. This is the major hurdle in the development of practical applications of electrospun fibers along with its low productivity. Here we are proposing to use the electric current in the electrospinning process to control the “quality of the fibers”. Electrospinning of a solution of polyacrylonitrile in dimethylformamide (PAN/DMF) was done by applying a programmed variable flow rate at different constant voltages. The electric current in the process was measured in real time. Four types of jet regimes were observed, electric current and the morphology of the fibers corresponding to these regimes were analyzed. A relation between the electric current, type of jet and morphology of the fibers has been established. The mechanical properties of electrospun fiber mats were also measured by a tensile testing method. POLYM. ENG. SCI. 46:954–959, 2006. © 2006 Society of Plastics Engineers     

Investigation on process parameters of electrospinning system through orthogonal experimental design

Electrospinning is a very simple and versatile method of creating polymer‐based high‐functional and high‐performance nanofibers. But most of the investigations are not systematic and describe the electrospinning process without quantitative accuracy. Inconsistent and even opposite results have been reported, which has hindered the consistent interpretation of the experiments. Orthogonal experimental method was used to investigate qualitative and quantitative correlations between fiber characteristics (diameters and morphologies) and the processing and materials parameters. Uniform fibers can be obtained without any beads by proper selection of the processing parameters, and a lower glass transition temperature was observed for electrospun fibers than that of native polymer. Results of statistical analysis showed that significant influences were observed for polymer molecular weight and solution concentration on fiber diameters, and there were significant effects of polymer molecular weight, solution concentration, and solvent system on fiber morphologies. Meanwhile, solution concentration and polymer molecular weight, and polymer molecular weight and solvent system had obvious interaction effects. Regression analysis revealed quantitative relations of fiber diameters and beads percent, that is, Y₁ = 72.8X₁ ? 8.1X₂ + 138.8, Y₂ = ?3.2X₁ + 0.4X₂ + 60.5, where Y₁ is fiber diameter (nm), Y₂ beads percent (%), X₁ solution concentration (%, w/w), and X₂ polymer molecular weight (kDa). Validation test showed that the experimental values of fiber size and beads percent were in good agreement with the calculated ones. Based on these results, optimal conditions could be obtained for predetermined diameters and morphologies for electrospun fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3105–3112, 2007     

PVP/PLA乳液静电纺丝成形及纤维毡亲水性能研究

利用乳液静电纺丝可制备一定复合结构的共混纤维,且可通过调控乳液的组成而实现聚合物溶液在低浓度下的静电纺丝成形。以聚乙烯基吡咯烷酮(PVP)水溶液为分散相,聚乳酸(PLA)氯仿溶液为基体相,制备不同水相比例的PVP/PLA乳液,研究了PVP/PLA乳液静电纺丝成形及其纤维毡的亲水性能。结果表明:乳液体系中PVP水相的加入可使PLA乳液在远低于其单独可纺溶液浓度下纺丝成形,所得纳米纤维随着PVP水相比例的提高而表现出纤维直径增加,并发生纤维集结成束,PVP大部分分布在复合纤维毡的表层,纤维毡呈现明显的透水性能;PVP的加入可有效改善PLA纳米纤维毡的亲水性能。     

熔体微分静电纺PBAT纤维膜的制备工艺研究

探究了聚己二酸对苯二甲酸丁二醇酯（PBAT）熔体静电纺性能,并研究了熔体微分静电纺工艺参数与PBAT纤维性能之间的关系。结果表明,随着纺丝温度的升高,纤维直径减小,纤维直径分布呈先减小后增大的趋势;随着纺丝电压的升高,纤维直径减小且分布均匀,纤维膜力学性能逐渐提高;当纺丝距离为9 cm,纺丝温度为260 ℃,纺丝电压为45 kV时,制备的纤维细度及均匀度最佳,其直径为4.31 μm,直径分布标准差为0.76,纤维膜拉伸强度为9.9 MPa、断裂伸长率为111.2 %。     

Effects of processing parameters on the filament fiber diameter of spunbonded nonwoven fabrics

The air drawing model of polymer in spunbonding is established. The air drawing model of polypropylene polymer in spunbonding is confirmed by the experimental results obtained with the help of our university's equipment. The predicted filament fiber diameter is in accordance with the experimental data. The effects of the process parameters on the filament fiber are investigated in this article. It is found that a lower polymer throughput rate, a higher polymer melt temperature, a higher primary air temperature, a higher air suction speed, a higher quench pressure, a higher venturi gap can all yield finer fiber, whereas the effect of the web basis weight is not significant. The results show great prospects for this research in the field of computer assisted design of spunbonding technology. POLYM. ENG. SCI., 47:510–515, 2007. © 2007 Society of Plastics Engineers.     

M_η对PS静电纺丝及超细纤维膜拉伸性能的影响

采用乳液聚合制备了不同相对分子质量的聚苯乙烯(PS),研究了相对分子质量对静电纺丝过程和超细纤维膜形态和性能的影响。使用乌氏粘度计测定PS的粘均相对分子质量(Mη),使用高速摄相机观察射流分裂行为,通过扫描电镜,万能拉伸机对制得的PS超细纤维膜形态和力学性能进行分析测试。结果表明:聚合所得不同Mη的PS都具有可纺性,超细纤维形态优良,Mη增大,稳定射流越长,平均直径从0.3μm增至3.0μm。纤维膜断裂强度也随Mη增大而增大。     

静电纺PLLA/PCL有序纤维的制备及性能研究

以三氯甲烷为溶剂,按聚乳酸(PLLA)/聚己内酯(PCL)质量比70/30配制质量分数3%的溶液进行静电纺丝,接收装置为转筒,电压为10 kV,接收距离为25 cm,推进速度为1.0 mL/h,制备PLLA/PCL有序纤维膜。通过对有序纤维膜进行扫描电镜、X射线衍射、动态力学性能以及力学性能测试,讨论了转筒的表面线速度对PLLA/PCL有序纤维膜性能的影响。结果表明:随着转筒表面线速度的增加,收集的有序纤维接近于平行排列,纤维的排列有序度提高;转筒表面线速度为3.75 m/s时,收集的有序纤维膜的晶粒尺寸及结晶度达到最大值,拉伸强度也达到最大值;转筒表面线速度大于3.75 m/s,收集的有序纤维膜的结晶度和晶粒尺寸减小,拉伸强度降低;转筒表面线速度为3.75 m/s时,得到的PLLA/PCL有序纤维膜的综合性能最好。     

Systematic parameter study for ultra-fine fiber fabrication via electrospinning process

Processing parameters effects on the morphology such as fiber diameter and its uniformity of electrospun polymer nanofibers was investigated. A processing map summarized effects of solutions properties and processing conditions on the electrospun nanofiber morphology was obtained. Polymer concentration, its molecular weight, electrical conductivity of solvents were found as dominant parameters to control the morphology. Based on the systematic parameter study, electrospun PLLA fibers as small as 9 nm were successfully produced.     

Influence of electrospinning parameters on poly(hydroxybutyrate) electrospun membranes fiber size and distribution

Poly(hydroxybutyrate) (PHB) obtained from sugar cane waste was dissolved in a blend of chloroform and dimethylformamide (DMF) and electrospun at 40°C. By adding DMF to the solution, the electrospinning process for the PHB polymer becomes more stable, allowing complete polymer crystallization during the jet travelling between the tip and the grounded collector. The influence of processing parameters on fiber size and distribution was systematically studied. It was observed that an increase of tip inner diameter promotes a decrease of the fiber average size and a broader distribution. Conversely, an increase of the electric field and flow rate produces an increase of fiber diameter until a maximum of ～2.0 µm but for electric fields higher than 1.5 kV cm^?1, a decrease of the fiber diameter was observed. Polymer crystalline phase seems to be independent of the processing conditions and a crystallinity degree of 53% was found. Moreover, thermal degradation of the as‐spun membrane occurs in single step degradation with activation energy of 91 kJ mol^?1. Furthermore, MC‐3T3‐E1 cell adhesion was not inhibited by the fiber mats preparation, indicating their potential use for biomedical applications. POLYM. ENG. SCI., 54:1608–1617, 2014. © 2013 Society of Plastics Engineers     

静电纺丝制备MWNTs/PVA/PEO复合超细纤维

采用硝酸对多壁碳纳米管(MWNTs)进行纯化处理,利用表面活性剂十二烷基磺酸钠(SDS)或聚乙烯醇(PVA)对纯化后的MWNTs进行了表面修饰,将修饰后的MWNTs添加到PVA和聚氧化乙烯(PEO)共混水溶液中,通过静电纺丝制备了MWNTs/PVA/PEO复合超细纤维。结果表明:PVA修饰的MWNTs比SDS修饰的MWNTs在PVA/PEO纺丝液中有更好的分散稳定性。随MWNTs添加量的增加,纤维的平均直径减小;当添加PVA修饰的MWNTs质量分数为0.53%时,纤维平均直径达368 nm,且纤维表面光滑、分布均匀。     

碳纳米管/聚合物纳米复合纤维静电纺丝研究进展

简述了静电纺丝装置的发展及其基本原理;介绍了静电纺丝制备碳纳米管/聚合物纳米复合纤维的技术进展,主要技术是碳纳米管在聚合基体中的分散性以及二者之间的界面结合力;详述了碳纳米管/聚丙烯腈纳米复合纤维和碳纳米管/聚氧乙烯(PEO)纳米复合纤维的制备及技术进展。指出今后应进一步发挥碳纳米管的性能,改进静电纺丝装置。     

电纺丝形成纤维的过程分析

采用静电喷雾等方法研究了聚丙烯腈 (PAN) ,聚间苯二甲酰间苯二胺 (MPIA) ,聚对苯二甲酰对苯二胺 (PPTA)的电纺丝成纤过程。结果表明 ,高聚物溶液受电场力及表面张力的影响形成喷射细流 ,两种作用力的扰动及作用引起射流的不稳定 ,从而发生射流分裂 ;在相同电纺丝条件下 ,PAN纤维细度远大于PPTA及MPIA纤维细度。