异形玻璃纤维及其研究进展

介绍了异形纤维的分类、横截面类型及评价方法,简述了异形玻璃纤维的成形方法。介绍了国内外喷嘴的设计、漏孔的设计和流股异形度的保持等装备和技术,综述了国内外异形纤维研究进展。最后认为,异形纤维具有广阔的应用前景,同时也具有较大的技术开发空间。     

中间相沥青熔纺异形纤维的工艺研究 Ⅱ.纺丝工艺及纤维形态

利用中间相沥青熔融纺丝法,制得中空、条形、Ｙ形等异形纤维,介绍了异形沥青纤维的纺丝特点。分析了影响纤维异形度的因素,纺丝温度降低时,熔体粘度大,流动阻力大,有利于提高纤维的异形度。研究发现,异形喷丝孔的截面积大,可以实现较大的拉伸倍数,同时其当量直径小,对熔体分子剪切作用大,纺出的异形纤维的取向度高于圆形纤维。     

吸湿排汗聚酯纤维的生产技术

介绍了吸湿排汗纤维的原理、制备方法及异形喷丝孔结构对聚酯纤维吸湿排汗性能的影响,分析了各道工艺对异形度的影响。生产实践表明:加入亲水性基团、降低纺丝温度、采用亲水性油剂等,不仅能增加纤维异形度,而且可提高纤维吸湿排汗效果。     

聚酰胺6纤维笔头的制备及其性能研究（英文）

采用异形截面的聚酰胺6(PA 6)纤维作为主体材料,聚氨酯胶黏剂作为粘合材料,制备了具有高吸水率的PA 6纤维笔头,主要用作软笔笔头。研究了PA 6纤维的异形度对纤维笔头的孔隙结构的影响规律,探讨了异形截面纤维的异形度对纤维笔头的硬度、孔隙尺寸及分布、吸水率、引水时间的影响。结果表明:PA 6纤维的异形度对纤维笔头的硬度影响较小;十字形截面纤维笔头的内部孔隙尺寸偏小,且分布集中,三角形截面的纤维,笔头内部存在尺寸较大的孔隙;随着PA 6纤维异形度的增加,纤维笔头的吸水率上升,引水时间受纤维截面异形度和截面形状的影响;其中十字形截面纤维异形度最高,达到61.71%,对应纤维笔头的吸水率最高,为61.86%,饮水时间最短为40.58 s。     

纺纱

加工异形纤维和中空纤维比加工普通合成纤维容易。异形纤维在梳毛(棉)机上梳理很少缠绕,纤维开松好,成条质量高。这种纤维经梳理后,所含短纤维的百分率较低,在精梳中精梳损耗小。而平均纤维长度较长。 异形中空纤维的纺纱,比异形截面纤维更为良好。在梳毛机上可制得整齐的纤维网,其     

异形纤维纺丝技术探讨

论述了异形纤维的纺丝技术 ,着重探讨了喷丝孔形状 ,聚合物摩尔质量、纺丝温度、熔体压力 ,喷丝板拉伸倍数 ,冷却条件与纤维异形度之间的关系。指出了不同孔形纺制的异形纤维 ,异形度相差很大 ;随着摩尔质量增加 ,异形度变大 ;温度和压力提高 ,异形度下降 ;纺丝速度影响不大 ;泵供量加大 ,冷却条件加剧 ,可使异形度上升     

拉伸对异形聚丙烯腈原丝截面形状的影响

研究了湿法和于湿法纺制异形聚丙烯腈(PAN)纤维过程中拉伸对纤维截面形状的影响。结果表明:喷丝头拉伸对湿法纺制的PAN初生纤维截面影响明显,随着喷丝头拉伸倍数的增大,纤维异形度逐渐增大;喷丝头拉伸对于湿法纺制的纤维截面形状和异形度影响较小;沸水拉伸对二者的纤维截面形状和异形度几乎无影响。     

化学纤维异形度指标的表征方法

通过分析FZ/T 50002—1991《化学纤维异形度试验方法》中的异形度测试、中空度测试和特征值测试的方法,提出了选择指标的思路:不仅要从几何角度,更要从功能角度考量。针对异形纤维因截面形状变化带来功能上的改变,进一步阐述了具体指标的改善设想,为建立新的指标体系,应对今后新型截面纤维的异形度测试,提供了研究基础。     

异形涤纶导湿性能研究

对异形涤纶的导温性能进行研究 ,设计了 7种异形孔并纺制纤维试样 ,分别测试它们的吸湿排汗能力、带液率、干燥速率。讨论同孔形不同尺寸的孔及不同孔形对异形纤维导湿性能的影响。结果发现 ,同孔形不同孔尺寸的异形纤维异形度随叶片长宽比的增加而增加 (控制在 7以下 ) ,纤维的吸湿功能与异形度有关 ,还与凹槽的深度、形状有关 ,H孔型的吸湿排汗功能最好     

异形异捻涤纶DTY的结构与性能研究

采用异形纺丝制备了6种不同规格的异形异捻涤纶拉伸变形丝(DTY),分析了纤维粗细节分布及截面形态对其结构与性能的影响。结果表明:异形异捻DTY中粗节的结晶度比细节的稍大,纤维的粗细节分布是影响其性能的主要因素;纤维中粗节率越大,其断裂伸长率和沸水收缩率越小,弹性回复率越好;在相同规格下,纤维粗节率越大,断裂强度和回潮率越大;圆形截面纤维的断裂强度较异形截面纤维的高;单纤维根数越多,截面异形度越大,纤维回潮率越大。     

Determination of refractive index profile of partially and highly oriented fibers using double refracting interference microscopy

Double refracting polarizing interference microscope designed by Pluta is used with a suggested method to determine the refractive index profile and birefringence profile of partially and highly oriented fibers. The application of this method depends on using Pluta polarizing interference microscope in two positions (crossed position for the duplicated images and subtractive position for the nonduplicated image of the fiber). The mathematical representation of the suggested method is given. The refraction of the light beam inside the fibers is taken into consideration while measuring the fringe shift profile. The refractive index profiles of polypropylene fiber with draw ratio 3.5 are determined using the conventional method. The results are compared with those obtained with the suggested method and found to be in good agreement. The suggested method is applied to determine the refractive index profile of poly(aryl ether ether ketone) partially oriented fiber and poly(ethylene terephthalate) highly oriented fiber. The diffraction of He–Ne laser beam is used to determine the average diameters of these fibers. Microinterferograms are given for illustration. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2341–2347, 2003     

Characterization of biodegradable core–clad borosilicate glass fibers with round and rectangular cross-section

Here, we report on core–clad bioactive borosilicate fibers, that we have prepared both with round and rectangular cross-section profile. The exposed approach, which relies on the stacking and drawing of glass slabs, demonstrates our ability to develop bioactive-based glass fibers with tailored cross-section profiles. Tens-of-meters-long fibers were successfully drawn, although suffering from elevated losses in the case of the rectangular ones. The response of the fibers in simulated body fluid was studied for both geometries. We found that a round cladding can act as protective layer, tempering effects of the corrosion. We also noticed that rectangular fibers are more prone to degradation, the enhanced corrosion beginning from their sharp corners as they accumulated residual tensile stress during drawing. To the best of our knowledge, this is the first report on the effect of residual tensile stresses from surface tension deformations applied to the corrosion of rectangular fibers. As geometry plays a critical role on the biodegradation behavior of the fiberglass, we believe the enclosed results could lead to the design of fiber devices with tailored cross-section profile in order to tune their rate of degradation on solely based geometrical effects.     

Birefringent approach for assessing the influence of the extrusion temperature profile on the overall orientation of as‐spun aliphatic‐aromatic co‐polyester fibers

Since the success of a production process depends on its good planning and having a clear plan from the raw materials until the final product, the focus of this research is in modeling of the extrusion temperature profile of as‐spun aliphatic‐aromatic co‐polyester fibers. The extrusion temperature profile affects the properties, productivity and product cost. In this work, as‐spun aliphatic‐aromatic co‐polyester fibers were spun under a fractional factorial design as a function of the extrusion temperature profile using appropriate statistical methods. The influence of the extrusion temperature profile on the optical birefringence of the as‐spun fibers was characterized. From the obtained results the overall orientation of the spun filaments has been modeled. For measuring the birefringence, an interferometric technique was employed and its microinterferograms were included for illustration. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

An overview on fabrication methods for polymer optical fibers

An overview of the most important materials and fabrication methods for polymer optical fibers is given. In addition to conventional fabrication methods a newly developed continuous melt spinning process for graded‐index fibers is presented that uses rapid cooling in a water quench for the profile formation. The approaches presented are divided into continuous and discontinuous processes for step‐ and graded‐index profile fibers as well as microstructured polymer optical fibers. The methods are described in detail and discussed concerning their efficiency, quality of produced fibers and scalability. © 2014 Society of Chemical Industry     

合成陶瓷纤维材料的制备工艺及发展趋势

作为先进复合材料的增强剂，高性能陶瓷纤维日益引起材料研究人员的广泛关注，并导致了纤维制备方法的不断发展。与其他制备方法相比，先驱体转化法更适用于制备细径、组成结构可调的陶瓷纤维，其中溶胶-凝胶法在制备陶瓷纤维方面已经显示出其优越性，并取得了巨大进展。论述了中国合成陶瓷纤维的起源、种类、性能以及应用，着重介绍了陶瓷纤维的制备方法，并指出了陶瓷纤维的发展趋势。     

添加共混方式对共混纤维成形及结构的影响

聚合物共混改性是制备功能材料最常用的方法,而对于纤维纺丝成形而言,直接共混和母粒添加共混的差异性未见有报道。以尼龙6为原材料,聚酯类添加剂为功能性共混物,分别研究了直接共混和母粒添加共混对纤维成形,共混纤维的物性的比较,结果发现,共混母粒纺丝成形所得共混纤维的机械性能优于直接共混纺丝成形共混纤维,且后处理效果优于直接共混纺丝成形,在添加的改性剂质量分数达30％以上时,后处理共混纤维的表面存在一定微细纤维结构,共混母粒纺丝成形所得共混纤维处理后纤维表面的微细纤维结构更为细小和均匀。     

Modeling birefringence in SiO2 glass fiber using surface stress relaxation

The retardance of silica glass fibers was evaluated using photoelastic techniques. Here, surface birefringence in glass fibers is shown to be a consequence of surface stress relaxation for as-received fibers drawn from Suprasil II. The surface features of the birefringent fibers were compared to a model of the residual axial stress profile resulting from a diffusion-controlled surface stress relaxation. Additionally, a uniform birefringence in the fiber equivalent to a constant tensile stress was recognized and attributed to structural anisotropy produced during fiber drawing. The contribution of structural anisotropy to the observed birefringence remained constant as the surface features were successively etched away. Surface compressive stress generation was also observed, as retardance corresponding to a surface compressive stress was found to increase with applied tensile stress during short heat treatments. Significant features of the retardance profile in as-received silica glass fibers, with a thin surface compressive stress layer and compensating interior tensile stress, agreed with the residual stress profiles predicted by the surface stress relaxation model after correcting for this observed structural anisotropy.     

微机图象技术及其在化纤异形度测试中的应用

本文通过对化纤异形度指标特点分析,给出了不同形状纤维截面的特征中心的数学定义,为用图象处理技术实测时,提供了方便。通过讨论理想三角形异形度指标间的相互关系,提出将D_R、D、T与C等指标及相应变异系数作为主要指标,S_T作辅助指标,其他指标不必列入标准。     

Simulation of polyimide fibers with trilobal cross section produced by dry‐spinning technology

As one type of high performance fibers, polyimide fibers can be prepared from polyamic acid (PAA) solution by dry‐spinning technology. The transformation from the precursor of polyamic acid to polyimides via thermal cyclization reaction in the dry‐spinning process is a main distinguishing feature, which is very different from other fibers produced by dry‐spinning such as cellulose acetate fiber and polyurethane fiber. In this report, the dry‐spinning formation of polyimide fibers with trilobal cross section from PAA solution in N,N‐dimethylacetamide is simulated via a one‐dimensional model based on a viscoelastic constitutive equation, combined with profile degree equation of cross section and imidization kinetics equation. The glass transition temperature, imidization degree and profile degree of the filament along the spinline are predicted by the model, as well as relative parameters such as solvent mass fraction and temperature. As a simulated result, solidification of polyimide fibers take place about 150 cm from the spinneret which is farther than for cellulose acetate fiber (70 cm). Moreover, the final profile degree of fiber is affected by many spinning parameters, such as spinning temperature, surface tension, spinning solution concentration, major, and minor axis length of the spinneret hole. POLYM. ENG. SCI., 55:2148–2155, 2015. © 2015 Society of Plastics Engineers