机织间隔织物的结构设计及其织造

间隔织物是一种特殊的三维机织物结构,首先探讨了间隔织物结构的影响因素,主要包括面板组织、垂向组织、垂纱跨距、垂纱密度等。以三维正交组织或平纹组织作面板组织,利用单根纱线或平纹组织来形成织物的垂向组织,改变织物的垂纱跨距或垂纱密度设计并成功制织了8种经向截面结构不同的间隔织物试样。阐述了织造间隔织物时上机张力的处理方法,最后呈现了试织成功的间隔织物的实物效果图。     

RS2DS—V型多轴向拉舍尔机

RS2DS—V型拉舍尔机可用于生产带有沿织物横向、纵向和斜向铺展的承重纱的织物,这四种方向的纱线由一编链结构(第五种)加以结接,这种织物对塑形加工十分灵活,因而织物可制成各种所要求的形状。这一点明显地区别于这些纱线被粘合或热熔,即硬直地固定起来的技术。由于使用了多轴向技术,使用者可根据     

蜂窝形和T字形立体机织物的织造要点

探讨蜂窝形和T字形立体机织物的织造要点。介绍了蜂窝形和纬向T字形立体机织物的设计与织造方法,包括截面形状设计、上机参数选择、上机图设计和织造步骤等。最终在普通小样织机上成功织造出了蜂窝形和纬向T字形立体机织物,节省了生产成本,织造的织物可控性好。认为:该类织物的规模化生产还需较长的时间才能实现。     

玄武岩长丝/芳纶双层间隔纱织物及其复合材料的制备

设计并试织了玄武岩长丝/芳纶双层机织间隔纱织物。双层机织间隔纱织物是一种特殊结构的三维立体机织物,其潜在的应用领域之一是纺织复合材料风机叶片的增强材料,根据风机叶片对增强材料性能的特殊要求,选择玄武岩长丝、芳纶做基本原料,设计并试纺了玄武岩长丝/丙纶包缠纱。试验结果表明:玄武岩包缠纱在300捻/m时断裂强力达到最大,可用于面层组织织造;选用芳纶纱线作为接结纱,以平纹作为面层组织和接结组织的基础组织。探讨了双层机织间隔纱织物结构的影响因素,形成了双层机织间隔纱织物的织造技术,丰富了三维立体机织物的组织结构库,采用手糊法制备了复合材料。     

包覆乳胶条的三维立体机织物的设计

本文设计的是一种包覆乳胶条的立体机织物,立体机织物由经纱、纬纱和乳胶条组成。采用的是一种柔软、回弹性好的圆柱形乳胶条和具有良好透气性能和透湿性能的棉纤维作为经纬纱。立体机织物由若干个重复的管状机织物单元组成,管状机织物为双层机织物,每相邻两个管状机织物单元共用一段机织物,用机织物将上下表面连成一个整体,得到一种整体性好、结构稳定、增厚容易、抗压更大,且具有良好透气性能和透湿性能的包覆乳胶条的立体机织物。     

纬编双轴向多层衬纱织物的几何结构

介绍了MBWK织物(纬编双轴向多层衬纱织物)的发展现状和性能特点,深入研究了MBWK织物的几何结构,在假设衬纱和绑缚纱在织物中具有理想截面形状的条件下,建立了MBWK织物的单胞几何模型.针对该织物结构的特殊性,文中首次提出了绑缚紧度的概念,即绑缚纱线圈实际长度与其几何长度之比,它和衬纱紧度共同影响着MBWK织物的成形性能.     

间隔机织物结构对复合板材平压性能的影响

探讨间隔机织物结构对复合板材平压性能的影响。分别设计织造了不同接结纱密度、接结纱高度和面层组织密度的间隔机织物,并制备了三明治型复合板材。对不同结构复合板材进行平压性能测试。结果表明:复合板材的平压强度随着接结纱密度的增加先增大后减小,存在最佳接结纱密度;复合板材的平压强度随着间隔机织物接结纱高度的增加而减小,随面层组织密度的增大稍有下降。认为:间隔机织物的接结纱密度控制在1.2根/cm2左右,接结纱树脂柱和泡沫填充材料可以协同作用,共同承压,此时板材的抗压能力较好。     

一种双锥体结构立体织物的设计与试织

为了得到双锥体结构立体织物,设计其结构为2.5D法向增强顶端封闭,由内外两层织物截面渐增或渐减形成双锥体,两层织物之间以纱线接结形成2.5D结构,其底面呈圆形或菱形,有正织和反织两种方法,正织方法通过逐渐减少两侧经纱得到锥体形状,反织方法通过逐渐增加两侧经纱得到锥体形状,同时反织采用了特殊的整经方法,把一根纱当从胸梁折回当两根使用,顶端完全封闭。     

玻璃纤维衬经衬纬纬编管状织物的制备及其拉伸性能

为获得结构稳定且紧密的玻璃纤维衬经衬纬纬编管状(WKBT)织物，探讨了机上及机下因地组织捆绑线圈织缩造成衬纱弯曲起拱的衬纱露丝问题。采用添纱工艺及扩布装置制备了4种地组织结构及捆绑纱种类不同的WKBT织物，并分析了其外观形貌、横纵密及拉伸性能。结果表明：添纱组织可改善脱圈后捆绑线圈周向的织缩，但衬纱起拱现象仍存在；扩布装置的应用解决了衬纱起拱的问题，结合添纱工艺可制备结构稳定且紧密的WKBT织物；4种WKBT织物经扩幅后衬纱仍具有较高的拉伸模量和衬纱强力利用率，证明本文方法在消除织缩的同时，可制备性能优异的WKBT织物。     

基于网眼结构的负泊松比经编间隔织物模型及其拉伸性能

为采用经编间隔编织技术构建具有较好负泊松比效果的三维结构,对负泊松比经编间隔六角网眼织物的结构建立几何模型进行数学分析,并采用拉舍尔双针床经编机进行试样织造。综合数学模拟计算和实际织造效果表明：经编间隔六角网眼织物的负泊松比性能主要取决于初始状态下3个轴向（尤其是y轴向）的收缩变形,在织造工艺参数方面主要由原料粗细、经编机机号、织物密度、网眼织物的组织,以及线圈纵行的歪斜角度决定,同时也受原料和织物刚度、间隔纱倒伏性的影响;间隔纱组织的连续同向垫纱更有利于织物ｙ 轴向的收缩变形,即更易于获得明显的负泊松比效果。     

Physical properties of ring,compact, and air vortex yarns made of PTT/wool/modal and wearing comfort of their knitted fabrics for high emotional garments

This study examined the physical properties of PTT/wool/modal yarns according to the yarn structure and the wearing comfort of their knitted fabrics for high emotional garments. For this purpose, the air-vortex, compact, and ring yarns and their knitted fabrics were prepared to analyze the wear comfort according to the yarn structure and the possibility of applications of the PTT/wool/modal blend fibers to air-vortex yarn. The wicking and drying rates of the air-vortex yarn knitted fabrics were superior to those of the ring and compact yarns fabrics, and the heat-keeping capability of the air-vortex yarn knitted fabric was higher than those of the ring and compact yarns fabrics due to the low thermal conductivity and maximum heat flow rate. In addition, the pilling of the air-vortex yarn knitted fabric was less than those of the ring and compact ones due to the air-vortex yarn structure with parallel fibers in the core part and the periodical and fasciated twists on the sheath part of the yarns. The tactile hand of the air-vortex yarn knitted fabric was harsher than those of the ring and compact yarns knitted fabrics because of the low extensibility and compressibility, and the high bending and shear rigidities.     

接结经纱对三维正交机织物结构的影响

以经纱接结的三维正交机织物为研究对象 ,在 3种接结纱张力下制织了 2种接结纱浮长的 6种正交机织物。通过比较织物的接结纱织缩率、纬纱密度和织物厚度 ,发现适当的接结纱张力既有利于形成较为理想结构的正交织物 ,又有利于织造的顺利进行 ;较小的接结纱浮长 ,有利于织物结构的均匀。     

飞轮缠绕用圆环织物的设计

为提高复合材料飞轮的径向强度,设计了径向也存在纱线的圆环形织物,它是按照飞轮层状展开得到的形状,经纱沿圆环的圆周方向,纬纱沿半径方向。分析圆环形织物在织造过程中经纬纱间的剪切变形,从织口到织物被织机的卷取成形辊握持,剪切变形角逐渐增大。剪切变形的存在,使机上圆环形织物的大小半径比设计值要小,而经纱密度变大。推导出织物机上尺寸与设计尺寸之间的关系,并可用于圆环织物的设计。实际制织了一种碳纤维圆环形织物,下机后经相反方向的剪切变形,得到了与设计相一致的结构。     

圆环形织物的织造原理与设计

研究了圆环形仿形织物的织造原理和设计。改造了现有织机的送经和卷取机构,采用纱架送经可满足仿形织物经纱不等长的要求;采用圆台形成型控制辊,既控制织物的卷取,又控制织物的形状结构,形成圆环形机织布,织物的纬纱沿圆台体的母线方向,经纱沿圆周方向。不等纬密仿形织物织造简单,但织物结构不均匀;等纬密仿形织物要求织机的开口机构复杂,纬纱分为与全部经纱交织的长纬和仅与部分经纱交织的短纬,应合理设计纬纱的完全组织循环和短纬在长纬中的分配,以使织物的结构均匀。     

The use of micro-computed tomography to determine the fabric cross-sectional area and stress

Accurate measurement of the cross-sectional area of porous fabric is quite important to determine fabric strength. Many models using yarns cross-section were built to calculate the strength of woven and knitted fabrics, and the spaces between fibres in the yarns were always considered to be part of the cross-sectional area. In our previous study, using micro-computed tomography (CT) and reconstructed three-dimensional (3D) images and based on the evaluation of the pore diameter distribution across the thickness direction, a new method was established to accurately determine the fabric ‘surface’ and fabric thickness. In this study, we used this method to calculate the cross-sectional area of fabrics and the resulting fabric stress. Using a plain weave and a flat knit fabrics showed that the cross-sectional areas in warp (or wale) and weft (or course) directions of the fabrics change regularly based on fabric structures and yarns. The fabric stress, when calculations were based on the least cross-sectional area, were greater than that calculated based on the other methods, such as the stress calculated based on the Peirce yarn model, where yarns are regarded as solid cylinders. Other research and properties related to the fabric thickness and cross-sectional areas will benefit from this accurate determination.     

Determinants of electrical resistance change of in situ PPy-polymerized stretch plain woven fabric under uniaxial tensile strain

Although the conductive stretchable woven fabric has been widely used as the sensitive material of strain sensors monitoring human motion, it is lack of a deep understanding of the determinants of its electrical resistance change under uniaxial tensile strain. This study chose two kinds of typical stretchable plain woven fabric, i.e. cotton/spandex core-spun yarn fabric and polyester/spandex filament yarn fabric, and they were coated by in situ polymerization of polypyrrole. Their electromechanical responses under certain uniaxial tensile loadings were measured and compared. Meanwhile, by a multi-architecture analysis, i.e. the intrinsic resistance of yarns, the contact resistance of interlacing yarns and the contact resistance of adjacent yarns in parallel, several hypotheses were proposed and tested to determine the determinants of electrical resistance change under tensile strains. The results showed that the resistance change in woven fabric with in situ polymerization of polypyrrole mainly depends on the contact resistance of the adjacent conductive yarns in tensile direction, and the electromechanical responses of the cotton/spandex core spun yarn are significantly different from those of the polyester/spandex filament yarn. It was concluded that the conductive yarn density and fabric structure are critical parameters of woven fabric as resistive strain sensor.     

纬编间隔床品面料的结构及性能分析

采用3.3 tex涤纶单丝为间隔纱,8.3 tex涤纶和2.2 tex氨纶交织为表层,制备4种不同密度、厚度及间隔纱连接方式的纬编间隔织物。分析织物组织结构和编织工艺,并测试力学性能和热湿舒适性能,分析面料厚度、密度与各项性能关系,用数学模糊分析法对面料进行综合分析。结果表明,间隔纱连接方式对面料拉伸断裂性和顶破性有一定影响,对透气透湿性无明显影响;厚度、密度较小且间隔纱交叉连接的织物综合性能最好;选择床垫面料时考虑厚度、密度及间隔纱连接方式对面料性能影响。     

2.5维机织复合材料的几何结构模型与验证

为验证2.5维机织复合材料结构与其力学性能的关系,基于对材料断面显微照片的观察和分析,假定纤维束截面为为跑道形,建立了2.5维机织复合材料的单元结构模型。借助模型推导出纱线在几种典型结构（浅交弯联、浅交直联、深角联）的单元体结构内的纱线长度、接结经的取向角和纤维体积分数,并对材料进行拉伸、压缩性能预测。制作了满足要求的2.5维机织复合材料实验件并对其进行力学性能测试,通过试验值和预测值的对比,验证几何模型的正确性。     

Sheet forming of woven fabric composite by combined cyclic stretch and deep drawing

The manufacturing of composites often requires transformation of 2-D fabrics into various structural 3-D shapes through preform processing without over straining of the yarns or wrinkling. Sheet forming of woven fabric composite by combined cyclic stretch and deep drawing was suggested. In order to prevent the wrinkling, the geometrical and mechanical properties of fabric should be chosen to get the final form of the prepregs beforehand. Geometrical investigation of the final bagged form dimensions are based on geometrical aspects of the wrapping of the fabric. In this study, an approach was proposed to form the reinforcement fabric composite through the dynamic bagging of the fabric by the application of cyclic stretching on the fabric during formation of 3-D reinforcement structure in hot environment. The dimensions of the flat fabric were calculated and the parameters of the forming process analyzed in two cases: hemisphere and flat top cone shape.     

三维正交机织复合材料的冲后压缩性能

为揭示纱线张力对三维机织复合材料抗冲击及冲后压缩性能的影响规律,基于多剑杆织造工艺,配置不同接结纱张力(25、50、100 cN)织造三维正交机织物,通过真空辅助树脂传递模塑成型工艺制备复合材料,并在室温下进行低速冲击及冲后压缩性能测试。结果表明：当接结纱张力为100 cN时,试样在冲击载荷下发生表层树脂大面积破裂和剥离并使纬纱失去支撑,同时,试样表层纬纱发生较大卷曲,促使压缩载荷发生屈曲失效;接结纱张力为100 cN试样的压缩性能相比接结纱张力为25 cN试样下降约50%;接结纱张力较高时易导致纬纱卷曲增大和树脂富集,并由此降低试样的弯曲刚度和冲后压缩性能。