32头环吹直纺技术探讨

结合32头环吹直纺的设备特点,对32头环吹直纺技术进行了探讨。结果表明:32头环吹直纺技术节能高效,技术先进。在32头环吹直纺生产中,将纺丝温度及组件压力适当提高,采用适合环吹生产的喷丝板及冷却上油工艺,制定合理的拉伸卷绕工艺,有利于多孔超细旦纤维的生产。     

粘胶长丝纺丝技术及设备的现代化

介绍了离心式纺丝机生产粘胶长丝存在的问题,连续式纺丝机的优越性以及连续式纺丝机的最新发展,指出了尽快改造和更新原有设备,推广应用连续式纺丝机的必要性。     

中介相沥青液晶熔体纺丝

阐述了中介相沥青液晶熔体纺丝工艺条件及其对碳纤维结构与性能的影响，讨论了单孔纺丝中各种纺丝工艺条件与纺丝稳定性的关系，介绍了几种新型纺丝方法如多孔纺丝、异形纺丝、复合纺丝、离心纺丝和熔吹纺丝，简要介绍了获得带形、Ｙ字形、三角形、中空形和线圈状碳纤维的制备工艺，最后指出使用狭缝形喷丝孔易于获得模量高达９３０ＧＰａ的超高模量碳纤维。     

高黏度聚乳酸(PLA)熔体微分离心静电纺丝

离心纺丝已成为制备超细纤维的有效途径,将离心纺丝和静电纺丝结合起来的离心静电纺丝,纺丝效率高、纤维细度低。但是目前离心静电纺丝相关的研究十分有限,且主要涉及溶液离心静电纺丝。为了解决这一问题,本文设计了一种基于熔体微分的熔体离心静电纺丝装置,选取聚乳酸（PLA）作为研究对象,探究了挤出机转速和流量的关系,得出挤出机转速在20r/min、流量为1.6089g/min时纺丝效果最佳。研究了离心盘转速、纺丝电压等因素对纤维的影响,得出增加离心盘转速可大幅细化纤维直径,离心盘转速提高1倍,纤维直径减小77.26%;纺丝电压的加入不仅可以细化纤维直径,而且可以提高纤维的结晶度。结果表明：熔体微分离心静电纺丝可以高效制备PLA超细纤维,并且通过改变实验参数可以控制纤维特征,为离心静电纺丝产业化提供实验依据。     

Highly Aligned Centrifugal Spun Polyacrylonitrile Nanofibers Collected and Processed with Automated Tracks

A parallel automated track collector is integrated with a rationally designed centrifugal spinning head to collect aligned polyacrylonitrile (PAN) nanofibers. Centrifugal spinning is an extremely promising nanofiber fabrication technology due to high production rates. However, continuous oriented fiber collection and processing presents challenges. Engineering solutions to these two challenges are explored in this study. A 3D-printed head design, optimized through a computational fluid dynamics simulation approach, is utilized to limit unwanted air currents that disturb deposited nanofibers. An automated track collecting device has pulled deposited nanofibers away from the collecting area. This results in a continuous supply of individual aligned nanofibers as opposed to the densely packed nanofiber mesh ring that is deposited on conventional static post collectors. The automated track collector allows for simple integration of the postdraw processing step that is critical to polymer fiber manufacturing for enhancing macromolecular orientation and mechanical properties. Postdrawing has enhanced the mechanical properties of centrifugal spun PAN nanofibers, which have different crystalline properties compared with conventional PAN microfiber. These technological developments address key limitations of centrifugal spinning that can facilitate high production rate commercial fabrication of highly aligned, high-performance polymer nanofibers.     

提高熔体直纺涤纶长丝强度的工艺探讨

通过对聚合及纺丝工艺条件的调整试验,研究原料及工艺条件变化对直纺涤纶全拉伸丝(FDY)断裂强度的影响,找出了影响直纺FDY断裂强度的因素有对苯二甲酸(PTA)质量、熔体黏度、冷却吹风速度、纺丝速度及拉伸比等。结果表明,选用优质的PTA原料,控制较高的聚合物熔体特性黏度,再通过调整纺丝及卷绕工艺条件,可改善纺丝性能,生产的涤纶FDY的强度可达4.8 cN/dtex左右,从而提高了长丝质量。     

Spinning the supercooled PET to obtain highly oriented and crystallized PET fibers at low speeds

An attempt has been made to investigate the feasibility for a novel concept of supercooled spinning to obtain orientation‐induced crystallization at speeds lower than that for the high‐speed spinning technology. This is achieved by setting the nozzle temperature lower than the melting point for PET, making the polymer a supercooled fluidic liquid, and then spinning the supercooled. The experimental results show that high orientation and high crystallinity can be achieved at a spinning speed of 2500 m/min, which is in good comparison with a speed of 5000–6000 m/min to obtain similar degree of orientation and crystallinity in the high‐speed spinning. The properties of the as‐spun fibers obtained by supercooled spinning were analyzed, and a rational theoretical account for the supercooled spinning is explored. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3078–3082, 2006     

不同纺丝速度下聚醚酯纤维结构与性能的关系

为了说明聚醚酯纤维的性能和形态结构与纺丝速度之间的关系,对聚醚酯切片设计了不同纺丝速度的熔融纺丝试验。结果发现:当纺丝速度增加为750 m/min时,纤维的断裂强度和回弹性较好。进一步通过同步辐射广角X射线散射、小角X射线散射以及双折射、声速取向试验,分析了聚醚酯纤维不同尺度的形态结构变化,发现在高纺丝速度下,形成了纤维取向度高、结晶度高、长周期小的形态结构。     

喷丝温度对PAN中空纤维成形与性能的影响

利用双弧狭缝孔形喷丝板,采用干喷湿法纺丝工艺,研究了PAN纺丝液在40～70℃喷丝温度范围内,对中空初生纤维成形与性能的影响。结果表明:喷丝温度对纤维截面的成形、外皮层厚度、异形度、中空度、声速取向等均会产生影响。随喷丝温度的增加,初生纤维外皮层厚度减小,纤维内外沿异形度逐渐降低且差距逐渐增加,中空度与声速取向在低温段降低幅度较大,而在高温段降幅减缓。     

Computer Simulation of Polyester High‐Speed Thermal Channel Spinning

A mathematical model to describe the thermal channel spinning (TCS) process in PET high‐speed melt‐spinning has been developed. This model, which is based on the spinning process kinematics, includes the effects of acceleration, gravity, and surfacial air friction. It incorporates the constitutive equation of PET polymer, the heat transfer related to the transverse air blowing and, in particular, to a convection and radiation combining procedure in the thermal channel, while taking into account the nonisothermal crystallization kinetics related to temperature and molecular orientation as well as the elongational viscosity of PET polymer connected with temperature, intrinsic viscosity and crystallinity. The developments of crystallinity, molecular orientation and morphological features of high‐speed‐spun PET fiber in the TCS process are investigated at take‐up speeds ranging from 3 600–4 400 m/min and thermal channel temperatures ranging from 160–200°C. The simulated results of this model are compared with the measured crystallinity, diameter, and birefringence of the spun yarn. The “necking point” in the TCS spinline can be predicted by this model.     

Water-born 3D nanofiber mats using cost-effective centrifugal spinning: comparison with electrospinning process: A complex study

A comparison of the electrostatic and centrifugal spinning of poly(vinyl alcohol) and poly(vinyl pyrrolidone) is shown in terms of the resulting fiber morphology and the process conditions. Specific parameters of centrifugal spinning, such rotational speed of spinneret and the relative humidity, were extensively investigated in details. Morphologies and diameters of resulting fiber mats were investigated by a scanning electron microscopy and compared between the two spinning techniques. The results revealed that formation of fibers is mainly affected by the initial polymer concentrations (and resulting viscosities) of polymeric solutions, which is in line with previous reports. However, the key novel finding of this work is that increasing relative humidity during centrifugal spinning process leads to greatly reduced fiber diameters to the levels typical for electrospinning. The obtained comparison is discussed and clearly shows technological advantages of the centrifugal spinning over electrospinning, enabling quantitative production of fibers with same or similar diameters.     

PAN基碳纤维原丝纺丝技术及其发展现状

简介了PAN基碳纤维原丝纺丝技术的发展进程.结合目前全球主要PAN基碳纤维生产企业碳纤维原丝产品的生产方法、专利及学术研究情况,分别对湿法纺丝、干喷湿纺、凝胶纺丝、静电纺丝、熔融纺丝等PAN基碳纤维原丝典型的纺丝技术以及知识产权情况进行了阐述和分析.指出我国碳纤维技术仍处于入门阶段,其发展受许多重要因素制约,必须把我国碳纤维产业化发展提升到国家战略高度予以重视.     

Production of Synthetic,Para‐Aramid and Biopolymer Nanofibers by Immersion Rotary Jet‐Spinning

Nanofiber production platforms commonly rely on volatile carrier solvents or high voltages. Production of nanofibers comprised of charged polymers or polymers requiring nonvolatile solvents thus typically requires customization of spinning setup and polymer dope. In severe cases, these challenges can hinder fiber formation entirely. Here, a versatile system is presented which addresses these challenges by employing centrifugal force to extrude polymer dope jet through an air gap, into a flowing precipitation bath. This voltage‐free approach ensures that nanofiber solidification occurs in liquid, minimizing surface tension instability that results in jet breakup and fiber defects. In addition, nanofibers of controlled size and morphology can be fabricated by tuning spinning parameters including air gap length, spinning speed, polymer concentration, and bath composition. To demonstrate the versatility of our platform, para‐aramid (e.g., Kevlar) and biopolymer (e.g., DNA, alginate) nanofibers are produced that cannot be readily produced using standard nanofiber production methods.

     

大容量生产线开发超有光缝纫线型涤纶短纤维

探讨了在5万t/a大容量涤纶短纤维生产线上生产1.33 dtex超有光缝纫线型涤纶短纤维的纺丝、牵伸工艺条件对产品质量的影响。结果表明:通过调整熔体黏度、纺丝温度、主风道压力、纺丝速度等因素,可以提高短纤维的断裂强度,降低断裂伸长率以及180℃干热收缩率,生产的1.33 dtex超有光缝纫线型涤纶短纤维质量稳定。     

Spinning speed–throughput rate relationships for polyester,nylon, and polypropylene fibers

The relationship between spinning speed and throughput rate has been investigated for fibers having the same fiber denier in the drawn state when produced by melt spinning of poly(ethylene terephthalate), nylon 6, and polypropylene polymers over a range of take-up speed (750–3000 m min^-1) and throughput rate. To understand the structural origin of the relationship, a limited amount of characterization of structure and properties of the as-spun and drawn fibers was also done. A comparison of the results for the three polymers shows that while the increase in productivity with increase in spinning speed is relatively less for polyester and nylon 6, it is quite high for polypropylene. The birefringence data show that while molecular orientation increases rapidly with increasing wind-up speed in polyester and nylon 6, the rate of increase is relatively less in the case of polypropylene. The possible reasons for the observed differences in behavior are discussed. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1773–1788, 1997     

国内化纤生产技术水平的提升空间与发展理念

扼要论述了国内化纤生产技术,诸如膨体连续长丝技术、涤纶工业丝技术、空气喷射技术、复合纺丝技术、纺丝成网技术、高性能单丝技术、短程纺丝技术、纤维素纤维的开发技术及产品结构等方面与国外的差距,阐明更新发展理念,正视差距,提升化纤生产技术水平的现实意义。     

PTT预取向丝的生产工艺

结合聚对苯二甲酸丙二醇酯(PTT)的特性,综述了PTT预取向丝的生产工艺及其后加工技术。PTT的POY纺丝完全可以适应PET和PA的高速纺丝设备,经过认真细致的工艺调试,并对纺丝装备作一些适当的改造,可以实现PTT预取向丝的工业化生产,制得成形良好、性能优异的PTT预取向丝,以便后加工的顺利进行。     

Behavior of melt electrospinning/blowing for polypropylene fiber fabrication

The fabrication process of polymer fibers has been analyzed in various ways, and several studies have been conducted to develop new processes and optimize existing ones. Several studies have been conducted on the electrospinning process, which can easily fabricate nanofibers, and the development of materials manufactured through electrospinning has also been investigated. However, research on the nanofiber fabrication and processing of thermoplastic polymers, such as polypropylene (PP), polyethylene and polyethylene terephthalate, is relatively lacking. Therefore, research on nanofiber fabrication is essential. In this study, PP fibers were successfully manufactured through a melt electrospinning/blowing process, which combined melt blowing and electrospinning. To analyze the melt electrospinning/blowing process, the dynamic behavior of the spinning process was observed using a charge-coupled device camera in real time, and the effects of the different spinning conditions were compared and analyzed. As the hot air or high voltage was increased, the spinning jet area tended to increase. In addition, the average diameter of the fabricated fibers tended to decrease as a high voltage was applied at a hot air pressure of 0.01 MPa; conversely, the average diameter tended to increase at a hot air pressure of 0.03 MPa. A similar trend was observed for the tensile stresses in the PP web fabrics. The polymer fibers produced by this melt electrospinning/blowing process can be applied as a production process for nanomembranes, filters and battery separators. © 2022 Society of Industrial Chemistry.     

对称型复合中空短纤维纺丝生产技术

探讨对称型复合中空纤维纺丝的生产技术。该产品技术利用了2种不同性能的熔体在同样的纺丝外界条件下具有不同的收缩性,从而形成天然永久性的立体三维卷曲。对关键技术如熔体的特性黏度,复合组件,中心吹风参数等进行了探讨。     

醋酸纤维高速纺丝成形工艺研究

通过研究醋酸纤维的纺丝生产流程,探索纺丝原液细流成形条件对生产过程及产品质量的影响,实现纺丝速度由535m/min提高到600m/min,同时改善了醋纤的产品质量。