Influence of Wires Properties on Warp-Knitted Loop Geometry in Plane Based on Theory of Elastic Rod

Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this problem,further analysis of loop geometry is done based on the theory of elastic rod with theoretical calculation and experiments.The theoretical analysis found that the distance between the contacted points at the loop root affected the loop geometry,and the distance was affected by the ratio of bending rigidity and the friction between yarns.The experiments,forming simple loop by taking the yarn as an elastic rod,found that the bending rigidity affected the loop geometry.Then the relationships between warp-knitted loop geometry in plane of metallic fabrics and wires properties were studied.The results show that metallic fabrics are more suitable for the theory of elastic rod;the friction and bending rigidity of wire yarns affect the loop geometry in plane.Also,the elongation of yarn affects the loop geometry in the actual warp-knitted fabric.

Effect of Run - in Ratios on the Mechanical Properties of Two - Guide Bars Warp - Knitted Fabrics

Warp knitting technology gets rapid development at present and becomes one of the most important parts of the textiles.But it is less known how the parameters of warp knitting technology affect the mechanical properties of warp-knitted fabrics.This paper presents discuss a research on the relationships between run-in ratio and mechanical properties of the two-bar warp-knittedfabrics through the measurement and analysis of the mechanical properties of various samples with different run-in ratios.The optimal run一in ratios for the reasonable mechanical properties are obtained from above dis-

Computer-aided Pattern Design of Multi-bar Warp Knitted Fabrics

To meet the development trend of multi-bar warp knit-ting machine towards high-speed,advanced technologyand computer control and the requirements of variousproducts with small quantity,there are many researcheson the computer-aided pattern design of multi-barwarp knitted fabrics.In terms of the special propertiesof the computer-aided pattern design of multi-barwarp knitted fabrics,the Object Oriented Program(OOP)programming-Object Windows class Library(OWL)programming is selected.According to thecharacters of the OWL programming,various functionsare defined.Pattern design and technical parameters canbe output,which offers a great convenience for the fac-tory.

The Mechanical Behaviour of Rubber Hose Reinforced with Warp Knitted Fabric

A new process for the rubber hose reinforced with warp knitted fabric was introduced, and the relation between the inside pressure and the radial expansion ratio of four kinds of rubber radiator hose reinforced with warp knitted fabric was investigated. The result showed that the bursting pressure and the radial direction expansion ratio of the hose could meet the requirement of ISO4081 for auto radiator hose. A new model was built up to analyse the relation between the inside pressure and the radial expansion ratio of the hose based the reinforced fabric structure parameters and yarn properties.

Manufacture of Single Cotton Fabric with New Composition, Specified Bend from Yarn Gathered from Local Raw Material Cotton Fiber

The article created 21 types of fabrics for the new composition of dublerin. Tests of various types of weave, fiber composition and yarn count are shown in various ways. The physical and mechanical parameters of the test samples were determined and analyzed at the “Accredited Testing Laboratory for Light Industry Products” at the State Unitary Enterprise “Namangan Center for Testing and Certification”. The reason for such a low performance of the motos of number 15 produced in the scientific research work is that the linear densities of the body and the yarn are four times different, despite the weaving of the fabric. Elongation at break is also dependent on penetration.

Research on Tearing Property of Reinforced Plastic Film with Bi-axial Warp Knitted Fabric Skeleton

The specification of laid-in and warp yams,thedensity of fabric and the specification of groundyam are of great importance when the bi-axialwarp knitted fabric being knitted.In this paper,the tearing property of the reinforced plastic filmwith bi-axial warp knitted fabric skeleton istested and analyzed.The resuits show thatamong the three factors,the specification of laid-in and warp yam has the greatest influence onthe tearing strength of the reinforced plastic film,while the rest of them has secondary and lesseffect respectively,and there is exponential re-lation between the tearing strength of the rein-forced plastic film and the number of yams in thedirection of force.

The Impact of Fabric Weave and Anisotropy on the Poisson’s Ratio in Technical Fabrics

Poisson’s ratio changes during the tensile stress of technical fabric samples due to the anisotropy of technical fabrics.This paper examines the effects of the type of weave and the anisotropic characteristics of the technical fabric on maximum tensile force,corresponding elongation,work-to-maximum force,elasticity modulus,and Poisson’s ratio when axial tensile forces are applied to samples cut at various angles in the direction of the weft yarns of the technical fabric.In the lab,3 cotton fabric samples of constant warp and weft density with different structural weave types(plain weave,twill weave,atlas weave)were subjected to the tensile force until they broke at the following angles:0°,15°,30°,45°,60°,75°,90°.Based on the different measured values of technical fabric stretching in the longitudinal direction and lateral narrowing,Poisson’s ratio is calculated.The Poisson’s ratio was calculated up to a relative elongation of the fabric of 8%,as the buckling of the fabric occurs according to this elongation value.According to the results presented in this paper,the type of weave of the fabric,the direction of tensile force,and the relative narrowing of the technical fabrics all play important roles in the Poisson’s ratio value.The Poisson’s ratio curve of a technical fabric under tensile stress(i.e.elongation)is primarily determined by its behaviour in the opposite direction of the elongation.The change in the value of the Poisson’s ratio is represented by a graph that first increases nonlinearly and then decreases after reaching its maximum value.

3D间隔织物/改性空心微珠复合材料吸声性能研究

将3D经编间隔织物加入到空心微珠增强聚氨酯基复合泡沫塑料中,制备出新型3D间隔织物/改性空心微珠复合材料,并对所加入微珠进行界面改性,以改善其与聚氨酯基体的界面结合及吸声性能。采用阻抗管传递函数法对4种具有不同规格的试样进行吸声系数测试,对试验结果分析可知,改性后微珠在一定程度上提升此种新型复合材料的吸声性能,改性S60微珠增强的复合材料样品吸声性能更优。此外,该复合材料在中低频率下的吸声系数要小于高频率下的吸声系数。

填充物的力学性能对坐垫舒适性影响的仿真分析

将经编间隔织物和不同密度的海绵材料作为坐垫的填充物,通过分析坐垫上的人体体压分布情况,深入探讨坐垫的整体舒适度。首先,选择中密度海绵(28 kg/cm^(3))、高密度海绵(50 kg/cm^(3))及新型弹性材料经编间隔织物,分别对其进行力学性能实验。随后,采用有限元仿真法,对三种材料分别进行单轴压缩仿真,分析得出拟合度最高的本构模型;对经编间隔织物材料进行微元变形仿真,分析该材料变形量、压强、厚度三者关系的数学模型。最后,建立弹性坐垫和中国50百分位男性的人体臀部(软组织+骨骼)仿真复合模型,分析臀部与垫面的体压分布数据,并利用体压测试仪验证仿真数据的有效性。结果发现:仿真结果显示,中密度海绵、高密度海绵及经编间隔织物体压-应变拟合度最高的本构模型选低密度泡沫较合适;经过MATLAB进行二次多项式拟合可得出经编间隔织物的变形量、压强、厚度三者之间的数学模型;经编间隔织物弹性坐垫垫面的峰值比中密度海绵弹性坐垫垫面的体压峰值大,比高密度海绵弹性坐垫垫面的体压峰值小,整体垫面体压分布情况较海绵坐垫更均匀;体压测试仪验证仿真数据与实际测试数据小于5%,表明仿真实验可行。研究表明,经编间隔织物比海绵材料具有更好的支撑性和压力舒适性。这些实验结果以及虚实结合的方法可为未来弹性坐垫产品的材料选择及开发提供参考。

三维圆筒织物的织造工艺研究

为解决织造大直径三维圆筒织物时存在的边缝、缺经等问题,提出了一种三维圆筒机织法。根据三维圆筒织物结构,设计添经工艺,绘制纹板图,并在三维圆筒织机上进行织造。结果表明:采用三维圆筒机织法,应用弧形分布开口机构中的综眼和打纬优化后的纬密,并合理设计不同层的经纱数量,能够较好地织造出大直径的三维圆筒织物。认为:织物的尺寸以及规格由工艺结构、每次的卷曲长度、经纱纬纱数量及规格等决定,可以应用于大型筒状结构预制体的规格化、连续化生产。

基于印织工艺的图案变形问题研究

为了解决印织工艺中规整图案难控制的问题,选择不同织物组织结构与纱线密度为实验探究变量,通过在织机上进行丝网印花探究图案变形规律,并进行4个系列产品设计实践。结果表明:在相同纱线密度条件下,平纹、斜纹、缎纹组织纬向尺寸织造前后基本不变,但经向尺寸上,平纹变化较大(12.80%~14.50%),5枚3飞缎纹图案变化较小(8.50%~9.00%),2上2下斜纹变化波动范围也相对较小(10.25%~10.33%);同一纬密及组织结构下,经密为346根/(10 cm)时,纬向尺寸变化较大,且纬向尺寸与经向尺寸数据稳定性较差;经密为504根/(10 cm)和583根/(10 cm)时,纬向尺寸接近设定值且数据稳定;经向尺寸波动与经密成正相关性。通过研究与设计实践,根据不同织物组织结构及经纬密选取织缩率范围内的中间值计算出需要印花的尺寸,织造后可获得接近设定尺寸的图案,关于图案变形问题基本做到可控,并为新产品开发提供参考依据。

基于变截面复丝模型的机织物模拟

为解决机织物模拟时因纱线截面不变而导致纱线互相渗透、模拟效果失真等问题,提出一种变截面复丝模型作为机织物模拟时经纬纱的模型。从空间圆参数方程中受到启发,建立空间椭圆参数方程作为纱线的截面模型;提出一种椭圆等分算法,通过等分弧长的方式建立了复丝模型。从受力分析的角度分析纱线中心线上不同位置截面的受挤压程度,建立了平纹及非平纹组织的交织模型,并以压扁系数表示不同截面的压扁状态。研究结果表明:变截面椭圆与复丝相结合构成的经纬纱模型模拟效果逼真;交织模型在减少纱线渗透的同时,也更符合实际情况;模拟的机织物表层纹理清晰,达到了预期效果。

间隔织物-羊毛角蛋白气凝胶复合材料研究

采用羊毛角蛋白制备有机气凝胶,存在结构不稳定、力学性能较差等问题。为提升材料的性能,通过还原C法从废旧羊毛中提取R-角蛋白并制备角蛋白气凝胶,将特殊的三维立体结构经编间隔织物引入气凝胶中,开发出经编间隔织物增强废旧羊毛角蛋白气凝胶复合材料,并对废旧羊毛的溶解率、提取率以及材料的密度、力学及隔热性能进行测试与分析。结果表明,通过还原C法得到的羊毛溶解率为89.4%,R-角蛋白提取率为72.6%。复合材料的密度不超过28.23 mg/cm^(3),具备传统气凝胶低密的优良特性,同时经编间隔织物与角蛋白气凝胶原位复合后,材料的压缩性能显著提升,并仍具有良好的隔热性能。

基于Spline算法经编间隔织物的仿真建模

现阶段大多建模方法得到的模型保形性差,且缺少光照处理。文章提出一种基于Spline插值算法的建模方法,该方法保证曲线经过所有控制点,在三维空间上建立与实际织物基本相同的空间曲线,解决了以往所得模型保形性差的问题,并且通过VC++以及OpenGL开发工具,可以加上环境光照渲染、纹理处理等,使仿真模型更为写实,得到的仿真模型可以节省人力和物力及时间,能够在短时间内为设计人员提供更为准确的设计思路和方案。

经编间隔织物增强亚麻纤维/硅橡胶复合材料的压缩性能

通过将亚麻纤维/经编间隔织物与软质硅橡胶进行复合,制备8种具有不同结构参数的经编间隔织物增强亚麻纤维/硅橡胶复合材料试样。对复合材料进行平板压缩试验,探讨经编间隔织物结构参数、亚麻短纤维长度和质量分数对复合材料压缩性能和压缩能量吸收性能的影响。结果表明:由结构正切值较低的间隔织物和较长的亚麻短纤维制成的复合材料具有较好的抗压缩能力;亚麻短纤维质量分数过高时,复合材料内部摩擦增加,材料压缩性能降低,亚麻短纤维质量分数过低时,则无法有效增强复合材料的压缩性能。基于Spence不变量本构理论建立压缩状态下复合材料的细观压缩力学理论模型,对其压缩性能进行模拟分析与预测,结果表明,所建立的细观压缩力学理论模型可有效模拟20%形变内复合材料的压缩演化过程。

防暴雨面料的基材制备及其无氟防水整理工艺研究

为进一步提高户外面料的防暴雨性能,通过分析防暴雨面料基材结构对户外面料防暴雨性能的影响,优化无氟防水整理工艺,测试面料的防暴雨性能,确定防暴雨面料基材结构及无氟防水整理工艺。结果表明:在确定面料基材其他结构参数的情况下,无弹和机械纬弹面料的防暴雨性能相较于机械四面弹更优异;防暴雨性能随着纱线纤度和面料经纬密的增加而增加,面料组织结构对防暴雨性能影响较小。选定机械纬弹、纱线纤度为167 dtex、经纬密度为376×300根/(10 cm)的平纹面料作为防暴雨面料基材,对其进行防水整理,整理工艺为无氟防水剂R3质量浓度40 g/L、交联剂TF-569P质量浓度12 g/L、带液率60%,一浸一轧,焙烘温度170℃,焙烘时间90 s。经防水整理后,洗前防泼水评分为100分,耐水洗测试20次后防泼水评分仍然可保持在95分,进一步对单布进行邦迪斯门防暴雨测试,测试10 min时的防水等级可达3~4级,吸水率为12.5%,透水量为10 mL。该研究结果可为防暴雨户外运动面料的制备提供参考。

基于线圈结构的双针床经编毛绒织物三维仿真

为实现高效率、低成本双针床经编毛绒织物开发,在分析了双针床经编毛绒织物形成及运动规律的基础上构建了垫纱数码数学模型、穿经数学模型,由数学模型自动生成垫纱运动轨迹。探讨了成圈及衬纬结构形成的毛绒织物的编织规律及其工艺,在研究其线圈结构及毛绒形态的基础上,建立了理想状态下的成圈及衬纬毛绒线圈模型,结合毛绒仿真关键因素及生成工艺参数,利用C#和JavaScript程序设计语言在Visual Studio平台上进行编程,实现了双针床成圈型及衬纬型毛绒织物的三维仿真。通过与实物图对比,验证了该模型可以真实模拟实物花色效果,仿真效果相似度高,可有效解决毛绒花型设计局限性的问题,降低设计难度和生产成本,解决设计周期长的问题,提高了生产效率,使双针床经编毛绒织物的应用得到广泛推广。

基于非线性本构的织物膜材梯形撕裂数值分析

为提高针对织物复合膜材撕裂力学响应数值分析的精确性,本文基于连续损伤力学理论,建立了PVDF涂层织物膜材的非线性损伤本构模型。结合梯度为15°的偏轴拉伸试验,验证了非线性本构模型的精确性;并将非线性本构模型纳入数值分析,与传统三折线本构模型及梯度为15°的梯形撕裂试验结果进行对比,验证非线性本构在撕裂力学响应方面的精确性。结果表明:非线性本构模型可有效跟踪膜材实际应力-应变曲线。在撕裂力学响应方面,两种模型均能体现系列参数变化对撕裂性能的影响规律及相应撕裂机理,但非线性本构模型在破坏形态上能更好地体现膜材撕裂过程中拉剪耦合复杂应力影响。

基于汽车内饰用三梳经编织物3D模型的构建

针对复杂的三梳栉经编织物,文章采用Rhino建模软件对其几何结构进行3D建模。首先,基于NURBS曲线对三梳经编织物线圈部分和延长线部分分别建模,通过确定曲线控制点拟合得到精度较高的空间纱线中心曲线;其次,根据纱线直径通过扫掠完成各组线圈单胞模型的3D建模,并组装得到完整的织物模型;最后,根据织物的线圈轨迹,拟合得到经编织物的曲线方程,使得线圈轨迹数值化。结果表明,采用Rhino对经编织物进行三维仿真,方法简单可行,模拟得到的效果图线圈嵌套紧密且相互之间并无干涉,可以达到较好的织物效果。

基于PhabrOmeter^(■)的汽车顶棚用经编针织物复合材料风格研究

设计了4种不同结构的经编针织物,并与不同厚度的海绵软泡层和水刺非织造材料复合形成“三明治”结构的顶棚面料,基于PhabrOmeter^(■)法宝仪分别探讨了织物的结构参数和顶棚面料复合结构对顶棚面料手感风格的影响。发现,3把梳栉编织的织物硬挺度一般优于由2把梳栉编织的织物,但编织纱在部分横列缺垫时,织物硬挺度会大幅下降,柔软度增加,悬垂性变差。相较于经编针织物,复合2.0 mm海绵软泡的顶棚面料硬挺度、光滑度、悬垂系数和褶皱回复率降低,柔软度整体呈增加趋势。相较于复合2.0 mm的海绵软泡,当海绵软泡厚度增加到2.5 mm时,顶棚面料硬挺度、光滑度和悬垂性增加,柔软度和褶皱回复率降低。