Introducing and optimizing a novel mesh for simulating knitted fabric

In this paper, a mass spring system is developed to simulate the draping behavior of knitted fabric. A new type of mesh based on loop structure, which is called Loop mesh, is introduced. The effective properties on fabric drape are measured using the Fast system, and the experimental data are incorporated into the mass spring model to simulate the draping behavior of knitted fabrics. 3D shape of real drape behavior of fabric samples is achieved using depth camera. Then in order to reduce error value between simulated and real results, distances between mass points in the Loop mesh are optimized using the Imperialistic Competitive Algorithm (ICA). In order to investigate validity and accuracy of the Loop mesh, drape behavior of knitted fabrics falling over a square table are also simulated using common meshes. It can be found that the Loop mesh produced a closest drape shape to the real fabric drape than other mesh models. Finally, fabrics drape is simulated in other situations and compared with its real result to validate the proposed model. Results show that the optimized model is able to simulate the drape behavior of knitted fabric with error value of 4.29 percent.     

Enhancing accuracy of drape simulation. Part I: Investigation of drape variability via 3D scanning

The objective of this two part paper is to present a method of enhancing accuracy of fabric drape simulation using commercially available software. In Part I, we report results of an investigation of drape variability for a set of fabrics having varied mechanical properties, an essential step in defining accuracy for drape simulation. Results illustrate that fabric drape behaviour is highly variable and thus provide no single drape configuration to target with simulation. Development of a revolutionary method for capturing drape of actual fabrics and measuring that drape in a virtual three-dimensional (3D) environment is also presented. The method allows identical drape measurement processes to be implemented for actual and simulated fabrics and provides opportunity for use of additional measures to assess fabric drape in three dimensions. The accomplishments presented in this paper are utilized to demonstrate, in Part II, development of a relationship that enhances realism of particle model simulations generated using the commercial drape simulation software.     

A new approach to de‐curling force of single jersey weft‐knitted fabric

In this work, the curling behavior of cotton single jersey weft‐knitted fabric was studied using a new non‐destructive test method. Eighteen series of dry‐relaxed weft‐knitted fabric samples were produced with three different yarn twist levels (724.5 tpm, 807 tpm, and 890 tpm), two yarn twist directions (Z and S), and three different loop lengths (2.7 mm, 2.85 mm, and 3.2 mm). Curling behavior was characterized in terms of curling distance (CD), de‐curling force, and de‐curling energy. The results show that weft‐knitted fabric samples with a lower loop length and higher yarn twist level exhibited higher de‐curling force and de‐curling energy. It is indicated that the de‐curling force of weft‐knitted fabric samples produced from the Z‐twist cotton ring‐spun yarn is higher than that of the samples produced from the S‐twist cotton ring‐spun yarn. The regression analysis results also illustrate that de‐curling force and de‐curling energy are non‐linearly correlated with edge CD, and variation trends follow polynomial equations. The result of this research suggests that the curling behavior of weft‐knitted fabric can be predicted in terms of de‐curling properties.     

Investigation into the curling behavior of single jersey weft-knitted fabrics and its prediction using neural network model

This research investigates the effect of fiber, yarn, and fabric parameters on curling phenomenon of single jersey weft-knitted fabrics which is interpreted to have curling surface in both course and wale direction. Taguchi’s experimental design is used to estimate the optimum process conditions and to examine the individual effects of all controllable factors on curling one by one. The controllable factors are blending ratio of polyester to cotton fiber, yarn twist and count, fabric structure, knit density, and relaxation time. Results show that fabric structure and knit density have the most dominant effect on the fabric curling. The optimum conditions of minimum curling values were also determined. Finally, the curling surface in course and wale direction as a two features of curling phenomenon was predicted using artificial neural network which selects scale conjugate gradient learning algorithm based on process parameters of single jersey weft-knitted fabrics. Our findings confirm the good capability of artificial neural network algorithm to predict these features.     

纬编针织物耗纱量预测研究进展

针对纬编针织物在生产过程中耗纱量预测的问题,在研究单面和双面纬编针织物编织规律的基础上,选择面积法与累计线圈法预测织物生产中的耗纱量。探讨面积法与累计线圈法预测纬编针织物耗纱量的具体方式,并详细介绍了影响2种预测方法的主要影响因素--织物单位面积质量及基本组织线圈长度的计算方法,分析了2种方法的优点、不足及应用前景等,为进一步研究纬编针织物耗纱量预测提供理论基础,也为相关企业生产经营提供参考。     

纤维组分与针织组织对针织物悬垂性的影响

悬垂性对针织物的外观及内在性能都有重要影响,而不同纤维组分纱线和不同组织的针织物悬垂性能也有很大区别。选用相同支数的纯羊毛纱、纯腈纶纱、羊毛/腈纶70/30纱3种典型的针织纱和纬平针组织、1+1罗纹组织、2+2罗纹组织3种常规的针织组织,利用正交试验法分析纤维组分与针织组织对针织物悬垂性能的影响。研究结果表明:混纺比例不同的纱线品种对针织物的悬垂性有一定影响,针织组织对针织物悬垂性的影响特别显著,因此在设计针织服装时应该有针对性地选用不同组分的针织纱和针织组织,以实现理想效果。     

An elliptical model for lockstitch 301 seam to estimate thread consumption

A geometrical model for lockstitch seam 301 has been proposed based on elliptical profile to estimate the thread consumption. The realistic elliptical shape of a lockstitch 301 seam has been confirmed by observing cut section along seam line. In order to validate a model across the different fabric types, varieties of fabrics from woven shirting, woven jeans, knitted single jersey to nonwoven interlining fabric have been considered. The different number of plies (2, 3 and 4) of given fabrics have been stitched at different levels of stitch densities (3, 4 and 5 stitches per cm) to observe effects in prediction of these parameters. It is found that the error % is increasing with increase in stitch density and number of ply. The proposed elliptical model have been compared with other recent rectangular profile based models, it is found that the propose model is more accurate and generalised with less error %, as compared to other models across the different fabric types. Also there is a strong correlation obtained between practical (actual) thread consumption and predicted from model.     

3D打印纬平针面料的制备

为研究3D打印服装面料中纬平针组织的结构,预测打印效果,促进针织面料数字化和智能化生产,将3D打印技术应用到针织面料设计和生产中。采用3ds Max软件,根据NURBS曲线建模的方法,结合Peirce线圈模型对纬平针组织进行三维模拟,通过模拟实现了3D打印纬平针面料的可视化,可预测打印效果。采用Repetier-Host软件,对模拟的3D打印纬平针组织模型切片,采用熔融层积成型技术,通过设置打印参数对模型切片数据进行打印,得到3D打印纬平针组织针织面料。结果表明：该打印面料的效果与模拟效果高度吻合,线圈之间嵌套关系明显,打印面料光滑平整,打印精度高,属于环境友好型面料。     

Finite element modelling the mechanical performance of pressure garments produced from elastic weft knitted fabrics

Compression garments mainly produced from elastic knitted fabrics have attracted many attentions due to their medical care performances. Components’ characteristics of the pressure garments such as yarn and fabric structure affect significantly the pressure applied on the human body. In this paper, it is aimed to simulate the effect of yarn’s mechanical properties as well as fabric structure on mechanical performance of the compression garment. For this purpose, a precise geometrical model for fabric structure is needed by which the pressure applied to the body could be predicted. Accordingly, double jersey knitted fabrics containing elastane weft yarns were produced on an electronic flat knitting machine and the fabric tensile properties were measured in course direction. Using equations governing the fabric structural unit-cell, a real geometric model was created in a finite element software environment. Considering the linear visco-elastic properties for elastane weft yarn, stress-strain curve was extracted. The results obtained from numerical simulation were compared with the experimental data in order to validate the proposed geometrical model. The findings demonstrate a good agreement between experimental and simulation results.     

Permeability properties of single jersey fabrics made of hollow yarns

In this work effect of using hollow yarns on the permeability properties of the single jersey knitted fabrics were studied. Firstly yarns were produced by ring spinning machine using cotton, viscose and acrylic fibres in the mantle and water soluble polyvinyl alcohol (PVA) fibre in the core. Single jersey fabrics were knitted and PVA core was removed subsequently by washing process to create hollow yarn. Weight, air permeability and water transmission rate properties of fabrics were measured before and after washing and compared with reference fabrics. Due to the removal of PVA fibres from the yarn core after washing treatment, air permeability and water vapour transmission rate of the all kind of single jersey fabrics which were produced with hollow yarns increased as well as weight of the fabrics decreased which will cause more comfort during any exercise. It was also found that mantle fibre type and PVA ratio have significant effect on the fabric properties.     

纬编提花织物计算机辅助设计模型与算法

为方便快捷并准确地设计纬编提花织物,根据纬编提花织物的组织结构特点,通过数学建模的方法建立包括花型意匠图和工艺编织图的二维矩阵,分别对该类织物的花型意匠信息以及工艺编织信息进行数学描述,并根据不同种类提花织物的结构特点和形成原理总结出了由花型意匠信息向工艺编织信息转换的相应算法,包括单面均匀提花织物、横条反面双面提花织物、竖条反面双面提花织物、芝麻点反面双面提花织物以及空气层提花织物,并给出详细的转化算法。以芝麻点双面提花组织为例进行大量实验,结果表明本文算法实现了纬编提花织物的快速准确设计,为提花织物软件的开发奠定了基础。     

Understanding the influence of fibre,yarn and fabric parameters on UV protection of wool-knitted fabrics

This work investigated the influence of fibre, yarn and fabric parameters on the UV protection of fabrics. It proposed a model for UV interaction based on a theoretical hypothesis, targeted experimentation and statistical analysis. Undyed and untreated wool-knitted fabrics with varying mean fibre diameter, yarn linear density, yarn twist, fabric cover factor and fabric structure were examined. A statistical model was presented to report the relationship between fibre/yarn/fabric parameters and fabric UPF values. An optical model on the interaction between the UV light and a single jersey fabric was constructed to understand the penetration of UV light. The models were verified by the UV transmittance results of knitted wool fabrics. The results obtained from the statistical and optical models were used to propose a set of optimized parameters for lightweight summer/spring UV-protective knitted fabrics. Testing confirmed that these fabric parameters provided both high UV protection and good tactile comfort.     

基于ABAQUS的筒状纬编针织物拉伸力学性能模拟

为更好地了解筒状纬编针织物抵抗拉伸变形的能力,基于对织物试样尺寸测量得到的几何结构参数,借助Rhino 3D建模软件建立了纬编针织物线圈模型和筒状纬编针织物模型;同时利用有限元分析软件ABAQUS在单位线圈和筒状织物2个方面研究了筒状纬编针织物的纵向拉伸性能;对织物拉伸过程进行有限元模拟和实验验证,并对针织物拉伸过程中...     

影响竹浆纤维针织物起毛起球性的因素

为深入分析竹浆纤维针织物起毛起球性的影响因素,根据7种竹浆纤维纬平针针织物的基本结构参数和起毛起球性的测试结果,应用灰色关联分析法对织物基本参数与起毛起球性之间的关系进行了定性和定量分析.结果显示:对起毛起球性的影响程度依次为织物的面密度、纵密、厚度、纱线线密度、氨纶含量、织物横密和竹浆纤维含量;含氨纶纯竹浆纤维针织物...     

针织西服面料的挺括风格研究

为探讨针织面料在西服开发应用的要求与标准,寻找能够用于西服开发的针织面料,分别从弯曲长度、折皱回复性、悬垂性3个方面对针织面料的挺括风格进行量化分析。借助实验仪器以及数据处理得到弯曲刚度、折皱回复角、静态悬垂系数3项性能指标,以机织西服面料为参考标准,对针织面料的挺括风格进行研究分析。结果表明:6路变化罗马组织是较为适合针织面料开发西服的组织结构,其结构稳定性优于12路小提花组织以及变化间隔组织,降低纵向弯曲刚度与横向弯曲刚度的差异;织物厚度增加0.1 mm,折皱回复程度提高10%;织物密度控制在110~130线圈/(5 cm)时,悬垂程度达到机织西服面料的60%以上;6路变化罗马组织配合高织物密度能够使针织面料的挺括风格达到机织西服面料的80%。     

Impact of structural variations in hollow yarn on heat and moisture transport properties of fabrics

The use of hollow/microporous yarns plays an important role in enhancing the thermo‐physiological comfort properties of fabrics. Depending on structural variations in hollow yarn, heat and moisture regulation behaviours of fabrics can be affected significantly. In this study, three types of hollow cotton yarn fabrics, produced by introducing polyvinyl alcohol (PVA) filament in the core, PVA staple fibres in the blend and PVA filament in doubling with cotton spun yarn, are studied. All three types of pre‐hollow yarns and reference yarns are made with a variation in spinning technique (single roving/double roving) to prepare eight single jersey knitted fabrics. The hollow/microporous structure of the yarn is created by dissolving the PVA fibres using hot washing of the fabrics. On overall evaluation of the fabric’s thermo‐physiological comfort properties, the doubled hollow yarn fabrics are found to be better than other fabrics. In general, thermal resistance, thermal absorptivity, wicking and drying properties of all types of hollow yarn fabrics increase after repeated laundering, while air permeability, water vapour permeability and water absorbency of hollow yarn fabrics mostly decrease. In contrast with fabrics made from yarn produced through single roving technique, use of double roving technique only improves fabric water vapour permeability.     

Moisture Management Properties of Bamboo Viscose/Tencel Single Jersey Knitted Fabrics

Effect of bamboo viscose/tencel blend ratio on the moisture management properties of single jersey knitted fabrics has been studied. Moisture management properties, such as wetting time of top and bottom fabric surfaces, maximum moisture absorption rates of top and bottom surfaces, maximum wetted radii of top and bottom surfaces, spreading speeds of top and bottom surfaces, and cumulative one-way transport capacity and overall moisture management capacity have been considered and correlated to the blend ratio of bamboo viscose/tencel yarn single jersey knitted fabrics. It is observed that as the tencel content increases, the wetting time, absorption rate, spreading speed, overall moisture management capacity decreases but maximum wetted radius increases.     

竹浆纤维提花面料的开发和性能分析

在介绍竹浆纤维性能的基础上,阐述了采用28tex竹浆纤维纱线在四针道单面大圆机上编织提花面料的生产工艺,对面料的服用性能进行了分析,织物透气性和渗透性优于纯棉织物,面料有天然抗菌效果,光泽亮丽,手感柔软滑爽,悬垂性好,是一种高档服饰面料.     

几种特色单面纬编面料的开发

介绍了在4针道单面大圆机上开发特色单面纬编面料的编织工艺,包括六角网眼面料、斜纹面料、横竖条醋酸面料、起皱面料、乔赛面料。编织工艺包括原料规格、设备参数、织针排列、三角排列及面料参数等。从原料的角度出发,阐述了编织过程或染整过程中需要注意的事项,并对各个面料的特点进行了分析。     

Effect of blend proportion on thermal behaviour of bamboo knitted fabrics

This study presents the thermal comfort properties of single jersey knitted fabric structures made from cotton, regenerated bamboo and cotton–bamboo blended yarns. Cotton, bamboo fibre and blends of the two fibres (100% cotton, 100% bamboo, 50:50 cotton:bamboo, 67:33 cotton:bamboo, 33:67 cotton:bamboo) were spun into yarns of identical linear density (20?tex). Each of the yarns so produced was converted to single jersey knitted fabrics with loose, medium and tight structures. The thermal conductivity of the fabrics was generally found to decrease with increase in the proportion of bamboo fibre. The relative water vapour permeability and air permeability of the fabrics were observed to increase with increase in bamboo fibre content. Statistical analysis also indicates that the results are significant for air permeability, thermal resistance, thermal conductivity and relative water vapour permeability of the fabrics.