Effect of blending two fiber-grade polypropylenes with different molecular weight distributions on the physical and structural properties of melt-spun filament yarns

In this study, the structural and physical properties of polypropylene fibers produced from the blending of two types of polymers having similar melt flow index but different molecular weight distributions (MWD) were investigated. Polypropylene with broad MWD (V30S grade) was blended with polypropylene with narrow MWD (511P grade) in various fractions (from 0% to 100%) to produce melt-spun filaments. Although the fraction of 511P in blends is higher than 25%, the blending is effective. Increasing the fraction of 511P in the blend increases tenacity and decreases breaking elongation. Mechanical properties of drawn yarns show the same trend as those of as-spun yarns with the blend composition. For as-spun yarns, addition of 10% of 511P polymer increases birefringence in comparison with the V30S yarn. There is little or no effect of blend composition on the development of crystallinity. Drawing increased the birefringence and crystallinity of as-spun filament yarns, but the values of increase are different for the samples.     

Investigating the effects of draw ratio,hot-pin temperature,and overfeeding on the color values of air-jet textured polyester yarns

In this study, influence of draw ratio, hot-pin temperature, and overfeeding on the color values of air-jet textured yarns, which were produced from polyester partially oriented yarn, was investigated. Two different air-jet textured yarns were produced by setting the value of only one variable to its minimum and maximum, while the reference values selected for the production of the reference yarn were used for the rest of the variables. Six different air-jet textured yarns, which were produced by varying draw ratio, hot-pin temperature, and overfeeding, and the reference air-jet textured yarn were dyed with the same dyeing procedure. Some physical properties such as linear density, tenacity, and breaking extension of the air-jet textured yarns were measured and images of the cross-section of the yarns were taken. The color coordinates of the dyed yarn samples were also measured. The color differences of six yarn samples compared to reference air-jet textured yarn were calculated. Changing draw ratio, hot-pin temperature, and overfeeding affected the color values of the air-jet textured yarns according to the results. It was found that, overfeeding is the parameter that affects the color values of the air-jet textured yarn most.     

A comparative study on performance characteristics of multicomponent core-spun yarns containing cotton/PET/elastane

Abstract

This paper experimentally investigated the characteristics of different (filament and multicomponent) core-spun yarn type. Filament core-spun yarns comprised cotton covered drawn textured (DTY) polyester (PET) filaments with four different filament finenesses. Regarding the production of multicomponent (dual) core-spun yarns, both PET with four different filament finenesses and elastane with four levels of draft variable were fed simultaneously. Yarn samples were produced with modified ring spinning system at the same spinning conditions. As a control group, 100% cotton ring-spun yarn was also manufactured. Tensile properties, unevenness, imperfections and hairiness of yarn samples were determined. Also, fatigue characteristics of yarn samples were examined at two different loading of cycles. The results showed that filament fineness had a significant effect on all yarn properties being determined. Dynamic modulus and dynamic strain properties of yarns, filament fineness, elastane draft and number of cycle were found to be statistically significant at 0.05 level.     

Structure/Property Relationships of Poly(ethylene terephthalate) Continuous-filament Yarn

Two commercial PET yarns, one as-spun and the other highly crystalline and drawn, were annealed at l8°C under various conditions. Mechanical and thermal-response measurements were made under high transient-heating conditions by using a UMIST-built Universal Fibre Tester (UFT). Differential-scanning-calorimetry (DSC) measurements were also made. A middle endotherm was observed on DSC traces for both the PET samples that had been annealed freely (free to shrink). Further thermo-mechanical treatments of these pre-annealed samples were made and thermal, creep, tangent-modulus, and other mechanical properties are recorded. The experimental results show structural instability in the fibre morphology irrespective of the process histories.     

竹炭改性涤纶纤维／棉混纺纱线力学性能研究

为了研究竹炭改性涤纶纤维／棉混纺纱中竹炭纤维含量与混纺纱力学性能的变化关系,对不同混纺比混纺纱线在YG061电子单纱强力仪上进行拉伸性能、应力松弛性能测试,并对测试结果进行了分析和比较。结果表明：竹炭改性涤纶纤维／棉混纺纱的断裂强力随着竹炭改性涤纶纤维含量的增加先有逐渐减小的趋势,然后增大。竹炭改性涤纶纤维／棉的混纺比小于临界混纺比时,混纺纱的断裂伸长率变化趋于平直;一旦超过临界混纺比,随着竹炭改性涤纶纤维含量的增加,断裂伸长率迅速增大。在实际应用中,混纺纱最低断裂强度对应的临界混纺比在设计中应尽量避免选用。随着竹炭改性涤纶纤维含量的增加,混纺纱的弹性越来越好。     

Investigation on production,analytical models,and characteristics of monofilaments/staple fibers composite yarn

This study aims to develop a composite yarn comprising monofilaments/staple fibers with distinctive structures and performance. A modified ring spinning system was proposed for producing the composite yarn with three monofilaments and staple fibers. The spinning mechanism was analytically modeled, and the structures of composite yarn were studied by scanning electron microscopy and optical microscopy. The characteristics of polyester monofilaments/cotton composite yarns and the conventional cotton yarns were compared. Analytical and experimental results showed that three monofilaments were distributed around the yarn center forming a 3D spiral, and the staple fibers interlaced inside and wrapped outside of the composite yarn. Experimental results showed that the composite yarn had better tensile properties, less hairiness, and stronger abrasion resistance. As a result, the composite yarn exhibited a remarkable improvement over the conventional yarn, which could be a valuable proposition for specific purposes, such as offering fabrics with shape preservation based on good yarn’s rigidity, and even electromagnetic shielding effectiveness with metal monofilaments in yarns.     

丙纶高强丝的生产及应用

本文概述了丙纶及丙纶高强丝在国内外的发展概况、高强丝的性能及开发应用情况．介绍了丙纶高强丝的一步法和两步法生产工艺和设备，并就纺丝温度、纺丝速度、冷却成形、拉伸温度、拉伸倍数、拉伸速度等工艺参数进行论述。     

Polypropylene fibers modified by polyvinyl alcohol and montmorillonite

This paper describes the preparation of modified polypropylene (PP) fibers. The modified PP composite was prepared by compounding PP in the presence of polyvinyl alcohol (PVA), PP grafted with maleic anhydrate (PPMAH), and montmorillonite (MMT). The resultant PP/PVA/PPMAH/MMT nanocomposite was easily spinnable and the obtained fibers were able to undergo orientation, using the drawing process at which the PP matrix is oriented in the direction of the fiber axis. The thermal properties, degradation, and dyeability of the fibers were studied. The presence of PVA in the fibers supports both the formation of β-modification of PP crystallinity and facilitates the dyeability of the modified PP fibers.     

天然彩色棉/白棉混纺纱线色泽的预测

 为研究天然彩色棉/白棉混纺纱线的色泽与彩棉含量的关系,应用计算机测色配色系统Datacolour对5种不同彩棉含量的彩棉/白棉混纺纱线的色泽进行测试。结果表明随着彩棉含量的变化,色调的变化不很明显,明度随彩棉含量的增加而减小,饱和度随彩棉含量的增加而增大。根据5种试样的K/S值测试结果,运用Origin 6.1软件,经过曲线拟合得出混纺纱线的彩棉含量与K/S值的关系为一元线性关系。然后进一步运用回归分析,得出不同彩棉含量的彩棉/白棉混纺纱线的K/S值的预测范围。     

Bending and tensile properties of cotton/metal wire complex yarns produced for electromagnetic shielding and conductivity applications

Recently, there has been a growing interest in protective textiles that are produced in order to reduce detrimental effects that arise from electric and magnetic fields on biological organisms and particularly on human health. The main goal of this investigation is to develop conductive metal-based yarns with desirable properties. For the purpose of this study, by using copper and stainless steel wires and cotton yarns, core spinning technique was applied in order to manufacture hybrid yarns in modified ring spinning machine. Physical behaviour of complex yarns consisting of cotton yarn and metal wire was evaluated by investigating bending rigidity, tensile and hairiness properties of the samples.     

驱蚊芳香聚丙烯

已有许多在熔融阶段利用各种添加剂和其他聚合物改善合成纤维染色性和功能性的尝试性报道。为赋予聚丙烯驱蚊性,采用双螺杆挤出机,使全同立构等规聚丙烯分别与2.5%和5.0%（皆为质量分数）的β-萘-甲基酮共混,对生成的共混物进行熔融纺丝和拉伸,拉伸比为3。研究了熔体流动指数的变化对熔融共混纤维拉伸强力和染色性的影响;并用FTIR、DSC、WXRD、SEM和DTG分析法评估了改性聚丙烯纤维的结构变化、共混物的相容性等,分析了改性聚丙烯纤维的染色性,发现分散染料上染改性共混纤维染色性有所提高,并具有100%的驱蚊性,只是随着添加剂含量的增加,拉伸强力稍有下降。     

Analysis of mechanical and dimensional properties of the denim fabrics produced with double-core and core-spun weft yarns with different weft densities

Elastic structures are preferred for improving the elasticity and recovery properties of denim fabrics. With the intention of improving comfort during body movements in denim jeans, 10–35% elasticity is required. In this study, the effect of the composition of double-core (dual-core) and core-spun weft yarns and weft density on the mechanical properties of denim fabrics was investigated. For this purpose, different core materials were used in the production of elastic yarns. The sheath material was cotton for all yarn types. Yarn samples were spun with the same yarn count and twist coefficient. 100% cotton Ne 8/1 Ring slub warp yarns were used as warp yarn while double-core and core-spun yarns were used as weft yarns in weaving. The weaving process was performed with three different weft density values (16, 22, and 28 weft /cm) and the other production parameters were kept constant. Twill 3/1 woven fabrics were treated according to standard denim finishing procedures. After domestic washing processes, mechanical properties of the samples were tested and statistically evaluated.     

PP抗光氧老化纺粘非织物布的开发及其性能

利用ZN-P型紫外线耐气候试验机加速PP抗光氧老化纺粘布的老化过程,通过拉伸仪测试其老化实验前后的断裂强度和断裂伸长率,根据其损失率来判断抗光氧老化剂的种类、添加量及色母粒对所制备的PP纺粘布抗光氧老化性能的影响。结果表明,经阻胺类抗光氧老化剂改性的PP纺粘布,其抗光氧老化性能明显优于紫外线类抗光氧老化剂改性的PP纺粘布,当其质量分数为2%～2.2%时性价比最好。同时,色母粒的加入对PP纺粘布的抗光氧老化性能也有较大的影响。     

亚麻/聚丙烯针织结构预制件及其力学性能

为探讨制备环保型民用纺织复合材料的新途径,利用横机开发了以亚麻为增韧纤维,聚丙烯为基体的亚麻/聚丙烯针织结构复合材料预制件小样,并对其拉伸、弹性回复和顶破强力等力学性能进行测试,分析影响其力学性能的有关因素。研究表明:亚麻纱与聚丙烯长丝合股可有效改善其可编织性;亚麻与聚丙烯纤维体积分数比为50∶50的针织结构预制件的拉伸断裂性能、弹性回复性能及顶破强力都较优;四平结构预制件的拉伸断裂性能、顶破强力优于罗纹结构,而罗纹结构预制件的弹性回复性能优于四平结构;弯纱深度较小时,亚麻/聚丙烯针织结构预制件的力学性能较好。     

羽毛蛋白接枝共聚物对涤/棉经纱的上浆性能

为解决羽毛蛋白浆料对高比例含涤纶纱线上浆性能不佳的问题,在单体浓度相同的情况下,通过将不同量比的丙烯酸甲酯(MA)和丙烯酸(AA)单体共同接枝到天然羽毛蛋白的分子链上,制备出一系列具有不同分子结构的羽毛蛋白-丙烯酸-丙烯酸甲酯接枝共聚物。以此系列羽毛蛋白接枝共聚物对涤/棉(65/35)经纱进行浆纱实验,测试了浆纱的增强率、减伸率、耐磨次数及毛羽数量。结果表明:适量引入聚丙烯酸甲酯(PMA)接枝支链有利于提高羽毛蛋白对高比例涤/棉纱的上浆性能;与原纱相比,当MA与AA的量比为20∶80时,合成出的羽毛蛋白接枝共聚物浆料保持了良好的水溶性,涤/棉浆纱的强度提高了19.27%,断裂伸长率仅降低了19.76%,耐磨次数达到原纱的2倍有余,毛羽数量亦大为降低。     

Optimization of spinning parameters influencing the hairiness properties of polyester/cotton vortex yarn

The influence of vortex spinning parameters on the hairiness properties of polyester/cotton vortex yarn has been studied. Polyester/cotton yarn of 50:50 blend ratio has been produced in two different counts (Ne 20s and Ne 40s) each with four different spinning parameters (delivery speed, spindle size, feed ratio and nozzle pressure). Experiments are designed with the aid of response surface method. Accordingly, different samples are produced with three levels of each parameter. The hairiness index H and zweigle hairiness have been evaluated from the samples produced with these combinations. It is found that the hairiness index H of both coarser and medium count vortex yarns are influenced by all the spinning parameters considered for this study. Also, zweigle S3 values of both coarser and medium count vortex yarns are influenced by all the four parameters. The interactions of some of the spinning parameters have significant influence on the hairiness index, H of both coarser and medium count vortex yarn. Also, few of the interactions have significant influence on zweigle S3 values of both coarser and medium count vortex yarns.     

26—OPEN-END-SPUN CORE-SPUN YARNS

A mechanism for producing open-end-spun core-spun yarns is described, and the method of operation is explained. Examples of open-end-spun core-spun yarns are given. Yarn properties are discussed, attention being drawn to the different functions performed by the core and the sheath.     

Comparison between tensile and damage analysis of hybrid jute/polypropylene needlepunched nonwoven geotextiles produced from untreated and alkali treated jute fibers

The tensile properties of virgin and mechanically damaged samples are investigated for hybrid needlepunched nonwoven geotextiles consisting of untreated Jute/Polypropylene (PP) and alkali treated Jute/PP fibers in defined weight proportions. The damages in nonwovens were induced by two types of mechanical damages (circular hole and horizontal cut) in the center of hybrid nonwovens tested in the cross-machine direction. It was found that the horizontal cut was more detrimental than circular hole in nonwoven geotextiles consisting of jute (both untreated and alkali treated) and polypropylene fibers, specifically when the nonwovens were tested in the cross-machine (preferential) direction. Furthermore, Jute/PP hybrid nonwoven geotextiles were found to be notch-sensitive in nature. The ratio of damaged area of untreated and alkali treated Jute/PP nonwovens at the maximum level of tensile strain to that of the area of corresponding Jute/PP nonwoven determined in the beginning was found to be higher in untreated Jute/PP nonwovens. Similarly, Poisson’s ratio of untreated Jute/PP nonwovens was also found to be higher in comparison to alkali treated Jute/PP nonwoven geotextiles. The initial region of non-linearity of stress–strain curves matched well with that of volumetric deformation for both damaged nonwoven geotextiles. Accordingly, the initial region of stress–strain curves of damaged needlepunched nonwoven can be modeled as a linear region with constant volume deformation.     

Steam as an alternative fluid for air in spun-like texturing: effect of core-yarn draw and core-yarn heat setting on texturing performance

The objectives of this research work were to investigate the use of high-pressure steam in order to replace air in the production of spun-like textured yarns and to investigate the effect of core-yarn draw ratio and core-yarn heat setting on texturing performance. An existing air jet texturing machine was modified to supply either air or steam to the texturing nozzle. Using an identical nozzle, both air-jet and steam-jet textured yarns were manufactured. Results show that the core-yarn and textured yarn tension increase and the loop instability decreases when the core-yarn draw ratio is increased. Therefore, it can be predicted that the core-yarn draw ratio has influence on the performance of both air jet and steam jet texturing. Boiling water shrinkage of core-yarn as well as air-jet and steam-jet textured yarn increases when the core-yarn draw ratio was increased. However, steam-jet textured yarn has lower boiling water shrinkage than both core-yarn and air-jet textured yarn. Core-yarn heat setting does not have influence on core-yarn and textured yarn tension in the air jet texturing. In steam jet texturing, core-yarn heat setting reduces core-yarn and textured yarn tension. Therefore, it can be predicted that core-yarn heat setting is important for steam jet texturing.     

纺纱工艺对弹性转杯纱结构和性能的影响

描述了由上海东华大学开发的用以纺制不同结构性能弹性转杯纱的一种弹性转杯纱纺纱系统。研究了在改变加捻参数和氨纶丝牵伸倍数时弹性转杯纱的结构与性能。结果表明加捻参数和氨纶丝牵伸倍数对弹性转杯纱的结构和性能均有一定的影响,氨纶丝线密度也会影响纱线的性能。