Influence of process parameters on air speed in fibre transport duct of the DREF-III machine: Part I

Abstract

The present work deals with the measurement of air flow in the transport duct of the DREFIII friction spinning machine. In this work, the direction and speed of air inside the transport duct was measured with the help of a three-hole probe. Turbulence in the air flow was assessed with the help of a tuft probe. The influence of opening roller speed, drum speed difference and suction air pressure was studied on air speed inside the transport duct. The results show that air flow near the inlet zone of the duct is highly turbulent and there are large deviations in air velocity and direction of air flow. The middle zone of the inlet of the duct has much more streamlined flow. However, the variation in air speed and direction of air flow is comparatively less near the duct. It is also observed that air velocity in the duct is mainly influenced by the opening roller speed followed by suction air pressure. Drum speed difference does not have significant influence on the air velocity in the duct.     

涡流纺纱线的包缠加捻对其力学性能的影响

为探究涡流纺纱线的包缠加捻与成纱力学性能的关系,从理论上分析了涡流纺纱线拉伸过程中的纤维形变与受力,详细研究了涡流压力和纺纱速度对涡流纺纱线力学性能的影响.结果表明:外层纤维螺旋包缠特性对涡流纺成纱的力学性能起着决定性作用,涡流压力和纺纱速度为影响涡流纺包缠和加捻效果的主要因素;当纺纱速度为280 m/min时,随着涡...     

蜂窝光触媒纤维/棉混纺纱纺纱工艺及其性能

为了设计高质量的蜂窝光触媒纤维/棉混纺纱线,本文通过提高环境湿度,利用抗静电剂对蜂窝光触媒纤维进行预处理,纺出6组不同混纺比的蜂窝光触媒纤维/棉混纺纱线,在此基础上测试各组纱线断裂强度、断裂伸长率、毛羽指数和条干均匀度等指标并分析不同混纺比对成纱质量的影响,以探究最优混纺比。研究结果表明：当蜂窝光触媒纤维比例增加至35%之前,纱线的断裂强力和断裂伸长率将随之增加,当蜂窝光触媒纤维比例大于35%时,断裂强力下降,断裂伸长率依然呈递增趋势;条干均匀度和毛羽指数均呈先下降后增加的趋势。     

23—DEBLENDING IN ROLLER-DRAFTING

Roller-drafting causes fibre shear, and the consequential longitudinal migration of short fibres with respect to long ones leads to fibre-deblending. Furthermore, the drafting of a strand with a varying blend ratio along its length leads to variations in drafting-wave activity along its length. Thus, even with a perfectly autolevelled sliver, variations in blend become translated into irregularity in linear density in later processes. The textile material carries potential errors with it as it passes from one process to the next.

Data presented in this paper show quasi-harmonic variations in blend and in fibre properties along the length of slivers, rovings, and yarns. The error wavelengths of the variations were similar to those found in the normal testing of linear density. There is thought to be a connexion.     

工艺参数对喷气纱强力的影响

阐述了纺纱速度、前罗拉钳口与第一喷嘴隔距、纺纱气压三大工艺参数对喷气纱强力的影响 ,并通过实验找出了最优的参数。     

A study of the development and properties of carbon fiber bulk yarns

Initially, using carbon fiber tows as raw materials, the developed airflow dispersion method was adopted for bulking process. Subsequently, the bulk properties, the irregularity, the mechanical properties, the hairiness index and the ability to fix the resin of the carbon fiber bulk yarn were investigated. The results show that the basic variation range of the bulking intensity is 17.19–22.19%, the variation range of the irregularity is 21.65–29.11%, and the strength of carbon fiber tows after the blowing and spraying by the air is reduced by 18.7–25.6%. The tensile and breaking elongation of the carbon fiber bulk yarn is up to 13.80%; the length of the hairiness of the carbon fiber bulk yarn ranges between 1 and 3?mm. The hairiness level decreases dramatically with an increase of the hairiness length.     

浅谈三大工艺参数对喷气纱强力的影响

阐述了纺纱速度、前罗拉钳口与第一喷嘴隔距、纺纱气压三大工艺参数对喷气纱强力的影响,并通过实验找出了最优的参数     

Effect of key process variables on mechanical properties of blended vortex spun yarns

A study of significant factors and their interaction during vortex yarn spinning has been carried out to achieve desired mechanical properties of the polyethylene terephthalate/cotton blended yarns which can offer process and performance advantages. The key significant factors, i.e. feed ratio, air pressure and spindle size were varied in a mixed-level factorial design. The mechanical properties (count lea strength product, tenacity and elongation at break) were studied and feed ratio was found to significantly affect the tenacity and elongation at break of spun yarns. A significant effect of these parameters was observed on the diameter and hairiness of the Muratec vortex spun yarn.     

细纱机参数对混纺纱毛羽及其他特性的影响

就各种纺纱几何参数对混纺纱线毛羽产生的影响进行了研究。各种纺纱几何参数如升降动程、罗拉宽度、纺纱角度等是产生大量毛羽的成因。不同生产厂家生产的机器不同。处理材料的模式亦不同。为此提出了一个简单的理论估算方法，以分析各种因素的影响。机器不同，生产出的混纺纱中纤维组分亦不同。     

Investigation of the quality properties of open-end spun recycled yarns made from blends of recycled fabric scrap wastes and virgin polyester fibre

Recycled fibre obtained from fabric scrap wastes is characterized by its low quality properties in terms of inhomogeneous fibre type and non-uniformly distributed short fibre lengths, both of which negatively influences the production process and the quality of the recycled yarns made from it. One of the common ways to utilize recycled fibre in yarn production is to blend it with virgin fibres. In this research article, the quality properties of the open-end spun recycled yarns produced in different material and spinning parameters from blends of recycled fabric scrap wastes and virgin polyester fibres are investigated. As material and spinning parameters, yarn count, blend ratio, waste type, waste origin, twist coefficient and rotor diameter are selected and their effects on the quality properties of the recycled yarns are evaluated through statistical methods. Statistical results reveal that especially blend ratio, yarn count and twist coefficient significantly affect the quality properties. In general, incorporation of virgin polyester fibre to recycled fibre tends to bring about improvement in yarn quality.     

转杯纺复合纱与sirofil复合纱的性能对比分析

纺纱方式的不同使得纱线的结构和性能也不同。通过将转杯轴中心开孔,借助转杯负压的作用引入长丝的方法纺制转杯纺复合纱;通过在传统环锭细纱机上加装1个长丝喂入装置的方法纺制sirofil复合纱。测试分析这2种复合纱在相同规格和纺纱条件下其纵向形态、起毛性、毛羽、纱线表面纤维抽拔力和强力等相关性能。研究结果表明,转杯纺复合纱表面光洁,毛羽少,不易起毛起球,耐磨性能好,其强力稍低于sirofil复合纱。     

捻度对棉/氨纶/银丝包芯纱性能的影响

为了制备具有良好纺织特性的弹性导电纱线材料，以棉粗纱、氨纶、银丝为原料，通过设计原料的喂入方式及在环锭纺纱机的前罗拉与导纱钩之间附加定位装置，纺制以氨纶为纱芯、银丝与棉纤维螺旋包缠氨纶且棉纤维位于纱线表面的弹性导电包芯纱，探究捻度对纱线弹性、导电性、耐磨性和断裂强力的影响。以银丝紧贴氨纶表面包缠为模型，计算得到不同捻度下包芯纱中紧贴氨纶表面包缠的银丝长度的理论值。实验结果表明：包芯纱的弹性随捻度变化，在70捻/(10 cm)时包芯纱定伸长伸长弹性率、定负荷伸长弹性率较大；在包芯纱伸直(不伸长)状态下，纱线实测电阻值随捻度的增大而增大；在包芯纱伸长10%的状态下其实测电阻值小于伸直状态下等长度包芯纱实测电阻值，且在75捻/(10 cm)时伸长状态与伸直状态下的相同长度包芯纱的实测电阻值之差较小。     

The effect of air-jet nozzle structural parameters on new cotton rotor-jet spun yarn properties

In this paper, a hybrid spinning system the so-called “rotor-jet spinning method” which utilizes the air-jet nozzle in rotor spinning process is presented. Thus, air-jet nozzles with different structures of 90S, 90Z, 60Z, and 30Z (the values of 90, 60, and 30 are orifice angles and S and Z are air rotational directions) were designed and constructed and then mounted between the take-up nozzle position and doffing tube in a rotor spinning machine. The air-jet pressure was changed at 0.2, 0.5, 0.8, 1, 1.2 and 1.5 bar values. The physical properties of cotton rotor-jet spun yarns with yarn count 20 Tex and nominal yarn twist of 938 TPM were investigated and compared with that of normal rotor-spun yarn. The experimental results indicated that by utilizing a 90Z air-jet nozzle at 1 bar air pressure, the highest yarn tensile strength, abrasion resistance, and twist, and lowest elongation are obtained compared with those of normal rotor as well as rotor-jet spun yarns with 30Z, 60Z, and 90S air-jet nozzle types. However, the rotor-jet spun yarn irregularity produced with 90Z air-jet nozzle is almost identical to normal rotor-spun yarn. It is also shown that the rotor-jet spun yarn hairiness properties which were produced with a 90Z air-jet nozzle at air pressure values of 0.2, 0.5 and 1 bar is almost similar to normal rotor-spun yarn while the lowest yarn hairiness is achieved at air pressure value of 0.8 bar. The experimental results of this paper suggest that the newly developed rotor-jet spun yarn is superior to normal rotor-spun yarn from the point of view of yarn tensile, abrasion resistance, twist, and partially hairiness properties.

     

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.     

摩擦纺分梳、尘笼和输出速度对成纱强力的影响

提高摩擦纺纺制低线密度纱的成纱强力,是研究摩擦纺的一个重要课题。利用摩擦纺纺低线密度纱时,对分梳速度、尘笼速度和输出速度做了大量试验与分析。结果表明,纺纱线密度不同,应采用不同的分梳速度,纺低线密度纱时宜比纺中等线密度纱大些。在纤维输送状态一定的情况下,要合理确定摩擦比,以便获得最佳成纱强力值。在提高摩擦纺纱线强力方面,为确定分梳速度、尘笼速度和输出速度提供了依据。     

Influence of fibre strength and yarn structural characteristics on tensile failure of blended spun yarns: a prediction model

The study reports on the static failure behaviour of P/V blended ring, rotor and air-jet spun yarns explained on the basis of fibre failure coefficient. Fibre failure coefficient is an index introduced to represent fibre break and slip in combination occurring during tensile failure. Fibre break/slip during tensile failure is found dependent on fibre strength, fibre cohesiveness and internal structural developments in yarns. Tensile failure behaviour of ring, rotor and air-jet yarns found to be different owing to their difference in fibre consolidation mechanism. The contribution of individual components towards fibre failure coefficient varies with the spinning technology. An attempt has been made to develop mathematical models to explain the spun yarn failure behaviour under static condition. The developed mathematical models have incorporated the fibre property (fibre strength) and few structural characteristics of yarns which are strategically selected to justify the essence of models to enhance the prediction capability. Individual models are developed for ring, rotor and air-jet yarns owing to their structural changes caused by their inherent fibre consolidation mechanism. The developed mathematical models are free from assumptions and based on pure applied mathematics and have very high potential for prediction of spun yarn failure behaviour.     

The effect of core-sheath proportion on the characteristics of fabrics produced with hollow yarns: part II comfort and mechanical properties

The study aims to investigate the effect of hollow yarn structure and the sheath-core proportion of hollow yarns on the permeability properties of the knitted fabrics. In order to accomplish this, core yarns in the yarn count of 59 tex were produced by using cotton, viscose, wool, and polyester fibers in the sheath and different ratios of polyvinyl alcohol (PVA) in the core. After completion of yarn production on ring spinning frame, the yarns in the form of packages were used to produce plain knitted fabrics. Fabrics were then divided into two groups, one of which was washed during a time period in order to remove PVA from the core to obtain hollow yarn structure. Air and water permeability, and wicking properties of the knitted fabrics were measured before and after washing processes. Mechanical properties such as pilling and bursting strength of the fabrics were also examined. The results show that washing process and PVA proportion used to produce core spun yarns have a significant effect on the permeability and mechanical properties of the fabrics.     

Analysis of spinning process using the Taguchi method. Part V: Effect of spinning processvariables on physical properties of ring,rotor and air-jet yarns

Abstract

Effect of lap hank and drafts, of various spinning sequence of machines, was studied on physical properties of different yarns using Taguchi method and analysis of variance. The ring yarn is highly even and has the least number of thin places and neps but thick places are the least in rotor yarn. The air-jet yarn is the least even and has the highest number of thin places, thick places and neps. The total hairiness is the least on rotor yarn and number of hairs =3 mm (S3) the least in ring yarn. In air-jet yarn the total hairiness and S3 are the highest. The finer lap hank and higher card draft in preparatory process produces even ring and rotor yarns with lower hairiness. However, the higher speed frame draft improves the evenness of yarn produced from coarser lap hank and lower card draft. Lower ring frame, rotor and high air-jet draft improves the properties of the respective yarns. Increase in ring/air-jet draft increases S3.     

高光洁处理对聚酰亚胺短纤纱及其织物性能的影响

针对聚酰亚胺(PI)短纤维纺纱静电大、成纱毛羽多、后加工摩擦剧烈导致纱线品质大幅恶化的问题,创新提出了在后加工终端对多毛羽PI单纱进行高光洁处理的方法。通过研制纱线高光洁处理装置和理论模拟,分析了该装置引纱区与涡流包缠关键区的作用机制,应用装置的湿热涡流处理多毛羽PI单纱,并将处理前后的PI单纱实施倍捻和织造,获得PI股线及其织物。结果表明：与处理前相比,高光洁处理后的PI单纱有害毛羽去除率为97.69%、耐磨性提高48.84%,PI股线有害毛羽去除率为64.67%、耐磨性提高40.89%;处理后纱线所织造织物的柔软性、透气性、抗起毛起球性、抗静电性均得到改善。     

喷气涡流纺成纱工艺对色纺竹浆纤维针织物性能的影响

为研究喷气涡流色纺成纱工艺参数对色纺竹浆纤维针织物性能的影响,基于Box-Behnken设计方法,借助Minitab16软件,分析探讨了喷气涡流纺成纱工艺（喷嘴气压、纱线线密度、纺纱速度）对色纺竹浆纤维针织物断裂强力、透气性、悬垂性及耐磨性的影响。结果表明：纱线线密度减小,织物断裂强力下降,透气性和悬垂性先显著增加,而后略有下降;纺纱速度提高,织物断裂强力缓慢减小,透气性降低,悬垂性增加;喷嘴气压对针织物断裂强力、透气性、耐磨性均无显著影响,但当喷嘴气压增加时,织物悬垂性能先增加后降低;织物耐磨性主要受纺纱速度和纱线线密度的影响,且影响较为复杂。