转杯纺捻度传递长度的解析研究

通过转杯凝聚槽内须条的运动和受力分析,对转杯纺捻度传递长度进行解析研究,建立了数学模型.并分别以棉和涤纶为纺纱原料对捻度传递长度进行了数值计算,分析了影响捻度传递长度的各种因素.     

转杯纺自由纱段形态对其捻度分布的影响

通过对自由纱段的运动及受力分析，对自由纱段形态以及纺纱工艺参数对自由纱段捻度分布的影响进行了研究。研究表明：因自由纱段在杯内成弯曲形状，从而使得自由纱段捻度自假捻盘入口处向剥离点处不断减少，真至剥离点处纱条捻度甚至降到只有设计捻度的40%-80%。为了保证凝聚槽内一定的捻度传递长度，则须适当提高设计捻度，这就揭示了转杯纱设计捻度高于环锭纱的一个主要原因。高速细支时的剥离点纱条捻度相对于低速粗支而言要高，说明只要一些纺纱工艺参数如转杯直径、转杯速度、假捻盘规格等配合得当，转杯纺也可高速稳定地纺制细支纱。     

长丝/短纤维复合纱捻度测试方法的探讨

提出用最大长度法测定长丝／短纤维复合纱的捻度，对两种羊毛、聚酯短纤维混合须条／聚酯长丝Sirofil纱的捻度进行了测试并同解捻法、一次退捻加捻法的试验结果进行了比较分析。结果表明：最大长度法捻度测试结果大于一次退捻加捻法而小于解捻法，与解捻法比较接近；一次退捻加捻法捻度试验结果明显偏低，不太适合于长丝／短纤维复合纱的捻度测试。     

驼绒/水溶性维纶包芯纱的包覆效果及性能

采用改进的环锭纺细纱小样机,试纺了9种不同规格参数的驼绒/水溶性维纶包芯纱,考察芯纱张力、芯纱含量和捻度等因素对包覆效果的影响,并测试包芯纱的拉伸性能、条干均匀度和毛羽指数等指标,获得了最佳纺纱工艺参数.研究结果表明:适中的芯纱张力可以提高包芯纱的包覆效果;芯纱含量越小,纱线包覆效果越好,断裂强力越高;捻度越大,包覆效果越好,毛羽指数越小,但断裂强力先增加后降低.优选工艺参数:芯纱含量为19.1%~19.9%;捻度为300~325捻/m;在芯纱不断裂的情况下,提高芯纱张力有利于改善包覆效果.     

Coolmax复合纱线毛细效应与纱线捻度的关系

为了更好的发挥Coolmax复合纱线在改善织物干爽舒适性方面的作用，对Coolmax复合纱线在不同捻度下的毛细效应进行了测试，分析了Coolmax复合纱线的毛细芯吸效应与捻度之间的关系．结果表明：Coolmax复合纱线的捻度对其毛细芯吸高度的影响较大．随着复合纱线捻度的增大，其毛细芯吸高度先增大后减小，它们之间也存在一个临界捻度，可以通过选取适当的捻度来获得较高的毛细吸水高度。     

集聚纺集聚区须条变截面部分的力学分析

通过对集聚区内须条的集聚过程分析，建立须条变截面部分的力学模型，可以得出此部分须条是有附加捻度的，并且对影响这部分须条附加捻度的因素：须条与网格问的摩擦因数和负压的大小进行了分析，结果表明集聚区须条的附加捻度随着须条与网格问的摩擦因数和负压的增加而增加。     

高强涤纶三股绳制绳工艺探讨——高强涤纶三股绳的捻度与强伸关系

本文以高强涤纶为原料,进行三股高强涤纶绳索的试制工作。通过对加捻预张力、捻度、捻度方向及小支股加捻与否等一系列工艺参数对绳索强伸性能的影响试验,从中得出6mm三股高强涤纶绳较理想的工艺参数,并作了分析。     

转杯纺自由纱段形态对其捻度分布的影晌

通过对自由纱段的运动及受力分析,对自由纱段形态以及纺纱工艺参数对自由纱段捻度分布的影响进行了研究.研究表明因自由纱段在杯内成弯曲形状,从而使得自由纱段捻度自假捻盘入口处向剥离点处不断减少,直至剥离点处纱条捻度甚至降到只有设计捻度的40%～80%.为了保证凝聚槽内一定的捻度传递长度,则须适当提高设计捻度,这就揭示了转杯纱设计捻度高于环锭纱的一个主要原因.高速细支时的剥离点纱条捻度相对于低速粗支而言要高,说明只要一些纺纱工艺参数如转杯直径、转杯速度、假捻盘规格等配合得当,转杯纺也可高速稳定地纺制细支纱.     

低捻转杯纺纱理论分析——阻扭件、阻扭矩及其捻度分布模型

转杯纺纱过程中断头的主要部位在成纱形成过程的一段,此段捻度小、强力低.如果为了扩大转杯纱的应用范围以及改善转杯纱的有关性能,纺制低捻度转杯纱,则断头率进一步提高,生头成功率进一步降低.这里研究在转杯纺加捻区中加装阻扭件后,讨论分析加捻区中纺纱张力的变化,进而构成阻扭件产生的阻扭矩以及形成阻扭件前后区域捻度分布的变化并建立捻度分布模型.理论分析结果表明,加装阻扭件后,成纱捻度不变,但提高了自由端成纱形成过程一段的捻度,这对降低断头率、提高生头成功率有利.     

集聚纺集聚区须条等截面部分的力学分析

通过对集聚区内须条的集聚过程分析，建立须条的受力模型，发现须条在集聚过程中会产生附加捻度，并且对影响须条附加捻度的各种因素：异型管开槽长度、负压大小、须条和网格套圈间的摩擦因数以及异型管的曲率半径进行了分析。设计相关实验对集聚区内须条的力学模型进行了验证。结果表明所建立的集聚区内须条的力学模型是正确的。     

Analysis on the Characterization of the Twist Insertion Level and Its Effect of the Compact and Ring Spun Yarns

In this paper,the difference of the twist insertion levels of the compact and ring span yarns of the same count is analyzed based on the relationship of the yarn twist factor to the twist angle and the bulk density.It is proposed that the relationship of the twist angle,twist level,and the yarn diameter should be synthetically considered when evaluating the twist insertion level of the compact yarn.The twist angle of the compact yarn is smaller than that of the ring yarn with the same twist insertion level.This results from the ordered fiber arrangement and compact structure of the compact yarn.Experiment was conducted to verify the conclusions.It is also discovered that the selection of the twist factor of the compact yarn,which can be usually lower than that of the ring yarn by 10％-15％,can be determined based on the yarn tensile strength.     

转杯纺假捻盘作用现状研究

介绍了转杯纺假捻盘对纱线加捻过程影响作用的研究现状,分析和评价了几项比较具有代表性的研究,说明了假捻盘在转杯纺纱加捻过程中具有假捻、阻捻或捻陷作用的不同观点及其相应的分析方法,并对今后分析假捻盘在转杯纺加捻过程中作用的研究思路提出了建议。     

纱线动态加捻的理论研究 第一部分:动态加捻基本方程的建立

动态加捻过程的描速是成纱原理研究的基础,它能够帮助我们理解纱线结构和特性的形成过程并揭示一些提高生产效率、改善纱线质量的途径。在本文第一部分,我们从捻度流概念和纱线微元分析入手,推导动态加捻所遵从的运动学和动力学方程。运动学方程描述了纱线回转运动与捻度分布之间的关系,而动力学方程则给出了加捻力矩与纱线捻度以及运动学参数之间的联系。将这两个方程结合起来可以描述捻度波在运动纱线中的传播过程。     

Study of the Twist Distribution inside Rotor

In this paper, the kinematics and dynamics of the yarn on the navel were studied. A series of twist distribution curves were obtained by numerical calculation. The results show that the navel is essential to the false twist development on the yarn arm. The fiber surface properties, yarn linear density, rotor speed and diameter, navel design are all the parameters having remarkable effects on the false twist level inside rotor.     

Theoretical Study of the Peripheral Twist Extent Length in Rotor Spinning

The mathematical model of peripheral twist extent(PTE) length was set up by studying the kinematics anddynamics of the yarn in rotor groove. The value of PTElength was calculated by using numerical method, andthe factors affecting the PTE length were also discussed.The results show that the theoretical predicted value ofPTE length seems to be consistent with the measured val-ue. The yarn linear density and rotor speed have re-markable effects on PTE length. The parameters includ-     

Experimental Investigation of Yarn Twist Blockage

In twisting a yarn running over a guide surface, the twist inserted into the part in front of the guide is impeded to transmit freely to the part behind the contact zone. A new device has been set up for investigating twist blockage and yarn torque - twist simultaneously. Measurements of twist blockage in relationship to different parameters have been carried out by using a monofilament yarn and a multifilament yarn. The factors under consideration include the wrap angle, yarn tension and input twist.     

Effect of Static False Twist on Rotor Spinning

Many practices of the rotor spinning show that the false twist effect of the navel is much more complicated than that of the one point based friction model. Both ends of the yarn＇s twist and torque changes were analyzed under the static effect of the navel, and then established yarn twist ratio on both ends. It verified its correctness through simulation experiment by designing the experimental device, and analyzed the effect of navers radius on twist ratio.     

STRUCTURAL VARIATIONS OF HOLLOW SPINDLE WRAP SPUN YARNS

The structure of a hollow spindle wrap spun yarn depends greatly on the steadiness of bindertension and of balloon rotation.The two commonly used binder bobbin forms,the cop type andthe flanged type,both as sources of spinning condition fluctuation,are examined in order to revealtheir effects on the wrap spun yarn structure.False twist is introduced on hollow spindle spinningmachines in order to avoid strand breaks before it is tightly wrapped up.However,an investigationof the false twisti g-wrapping process shows that this inevitably causes irregular yarn tortuosity.     

静电纺纱加捻效率的初步研究

本文对静电纺纱的加捻机理和加捻效率进行了分析。通过实验测得了加捻管的机械加捻撩效率,从而得出了影响纱线捻度和加捻效率的主要因素。并采用二次回归通用旋转组合设计方法建立成纱捻度与加捻效率的回归方程。通过理论分析和实验结果所得结论是:在自由端须条上的假捻是影响加捻效率的主要因素,而机械滑溜相对来说比较小。影响纱线捻度和加捻效率的主要工艺参数是加捻管的转速和引纱速度。这两速度越高,总的加捻效率越低。