共查询到18条相似文献,搜索用时 843 毫秒
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基于ANSYS CFX的网络喷嘴内部流场计算 总被引:3,自引:1,他引:2
为设计出性能优良的用于化纤长丝网络加工的网络器,采用商业计算流体力学软件ANSYS CFX对网络器丝道内的可压缩流体进行模拟,并将模拟结果和以往的实验数据进行比较。结果表明,除了少数几个点外,计算结果和实验结果具有较好的一致性。此外,通过考察丝道纵向截面上的速度矢量的分布,认为丝道纵向截面上对称漩涡的分布有利于网络结的形成;通过考察横向截面上速度矢量分布,认为在较大的张力条件下,网络结不易形成;丝道中心处速度的大小决定了化纤长丝的开松程度。 相似文献
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网络器内空气压力平衡点的研究 总被引:3,自引:1,他引:2
用流场相似原理,将网络器尺寸按几何相似放大,定量测出丝道管内上下两股气流的压力,确定两股气流交叉处的压力平衡点位置及该位置与网络器丝道和气道直径比的关系,证明了丝道管内存在涡流现象。 相似文献
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正1油涂膜器导丝器生产和加工特殊长丝,如微细、超细长丝、特殊的原液染色纱线(纺前染成黑色和碳黑)和由包含添加剂(消光、碳钢、抗菌剂)的原料制成的长丝,对生产、机器和组件的要求较高。油涂膜器导丝器在熔纺过程中是一个决定性的组件,易受到极端磨损,为此需对其进行特别设计,提高其抗磨损性能,以使油涂膜器导丝器在使用期间有助于为纱线提供较好的表面 相似文献
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为探讨由多根单丝组成的长丝纱在受到拉伸作用时,发生单丝断裂的性能及其测试与表征方法,对一种锦纶6 无捻长丝纱进行了拉伸试验,获取了断丝发生的典型拉伸断裂曲线;通过分析该断裂曲线特征,建立了基于断丝频次和应力条件的表征长丝纱断丝性的指标体系;对3 种不同长丝纱进行了拉伸不同验,分别计算出表征长丝纱断丝性的指标并对其进行分析。结果表明:长丝纱在拉伸至断裂过程中,部分试样会发生单丝断裂现象,且可能不只发生1 次;每次单丝断裂均会在拉伸断裂曲线上形成一个锯齿状波形;长丝纱的断丝性可用一定次数拉伸试验中断丝发生的频次类指标和断丝发生时的应力类指标进行表征,发生第1 次断丝时的应力值越低,断丝频次越高,表明长丝纱越易发生断丝。 相似文献
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包芯纱线是双组份纱线的一种。它由位于纱的中心的芯丝和包覆层所组成,芯丝可以是化纤长丝、金属导线或其他纱线。包覆层可以是棉、毛、麻或其他纤维层。包芯纱线及其产品既具有天然纤维的外观和手感,也有化学纤维耐磨,耐拉伸、弯曲痨劳等特性,因而可以改善产品服用性能,促使机织、针织和装饰布产品品种的发展。本文介绍苏联的几种包芯纱线的制造方法及其工艺。一、用环锭精纺机生产包芯纱在普通环锭精纺机上加装长丝筒管架、导丝器、张力装置和断头时的长丝停喂装置(如图1)。长丝经导丝杆1、张力装置3和导丝器 相似文献
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双组份Tencel纤维复合纱的研制 总被引:1,自引:0,他引:1
介绍了在FA50 6环锭细纱机上纺制Tencel纤维、涤纶长丝双组份复合纱的方法及导丝轮、张力装置对成纱质量的影响 ;论述了合理的导丝器形式及长丝与外包纤维在钳口处的位置是提高包覆效果的重要条件之一。通过正交实验运用层次分析法 ,确定了成纱综合性能最佳时的捻系数及第二组份———涤沦长丝预张力的大小。 相似文献
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为研究旋流喷嘴纺纱方法对不同线密度纱线的减羽效果,借助计算流体软件模拟旋流喷嘴内部气流特性及不同线密度纱线在气流作用下的压强与速度分布,并用纺纱试验进行验证。模拟结果表明,进入纱道后的气流沿顺时针方向分别朝纱道入口及出口方向运动,纱线表面毛羽主要受到气流的包裹力和由于纱线自转而产生的相对包裹力作用。气流的旋转特性使得纱道管壁附近的压强高于轴线附近,因此不同线密度纱线的表面所处涡流的位置不同,受到的气流包裹力也不同。纱线线密度较小,表面受到的压强分布密集,x、y、z 向速度波动较大,其中20 tex 纱线表面的压强和速度分布情况优于10、30、40 tex 的。研究结果表明,旋流喷嘴压强在0.2 MPa 下,对20 tex 大麻/ 棉(40/60)的减羽效果最优,达到了87.6%,与数值模拟结果一致。 相似文献
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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. 相似文献
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An investigation of the effects of different weft–insertion–system parameters on yarn velocity is reported. Increasing the air–supply pressure, initial loop length, and running speed decreases the total insertion time and hence increases the average yarn velocity. To examine the effects of yarn characteristics on yarn velocity, several yarns were tested under the same laboratory conditions. For every yarn, relations between total insertion time, yarn velocity, and air velocity and distance were obtained. It was found that open–end–spun (OE) yarns had a higher yarn velocity than ring–spun (R) yarns owing to the bulkier structure. However, R yarns had a higher initial acceleration than OE yarns. Murata air–jet–spun yarns had a higher velocity than R yarns. Increasing the yarn linear density and twist increased the insertion time. Texturing of continuous–filament yarns increased the yarn velocity by comparison with straight continuous–filament yarns. 相似文献
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为探讨亚麻/有色涤纶丝包缠复合纱的混色特征,以及包缠捻度对混色效果及复合纱性能的影响,以有色涤纶网络丝为外包缠纱,亚麻漂白纱为芯纱,纺制不同颜色和捻度的包缠复合纱;分析了复合纱的外观特征,测试了纱线的拉伸性能、条干、纱疵和毛羽。结果表明:复合纱具有麻彩外观,芯纱粗节处包缠捻度大呈色浅,细节处捻度小呈色深,复合纱沿长度方向有弱段彩效果;改变外包缠纱的包缠捻度,可改变复合纱的混色质地和颜色深度;包缠复合可提高亚麻纱的断裂强力和断裂伸长率,改善纱线条干,减少纱疵和毛羽;包缠复合纱受到拉伸作用会发生芯纱和外包缠纱不同时断裂现象,但随着包缠捻度的增大,不同时断裂的发生比率会降低。 相似文献
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The torque in single-spun yarns is an inherent property of the twisting and bending of staple fibres during the formation of yarn combined with the effect of applied tension on the yarn. The consequences of yarn torque are well known and are widely observed as yarn instability, e.g., yarn rotation under tension; local snarling and entanglement at low loads, and as distortion in fabric, i.e., edge-curl and skewing in knitted fabric. In this paper, a method for predicting the yarn torque based on the radial basis function networks is presented and evaluated. This method uses a “universal approximator” based on neural network methodology to minimize noise during training of the network and to approximate the yarn torque as a function of the geometrical and physical parameters of yarns (twist, linear density) and the applied load. The current method is an integral radial basis function network-based approach suitable for textile engineering and gives very good prediction of yarn torque across a range of yarn structural parameters and test conditions. 相似文献