喷气纺喷嘴中气流场的分布规律

喷气纺纱中,喷嘴是决定成纱加捻包缠程度的关键,直接影响成纱质量,本文运用激光多普勒测速仪对喷气纺喷嘴中的气流场以及有关参数对喷嘴中气流场分布的影响作了测试分析,所得的结果对掌握喷气纺喷嘴中的气流场的分布规律、合理地设计喷嘴、优化有关参数等提供了依据。     

喷气纺纱条动态气圈的转速与成纱强力的关系

喷气纺纱是利用旋转气流作用推动纱条形成气圈运动,使头端自由纤维加捻成纱。本文采用本组研制的纱条气圈转速仪对喷气纺纱纱条动态气圈的转速进行了测试,并就改变加捻成纱过程中的第一喷嘴和第二喷嘴的气圈转速,探讨其与成纱强力的关系。     

双纱纺成纱区几何状态和单纱捻度的试验研究

在双纱纺纱中,交汇区中的单纱捻度和交汇角对成纱的性能有很大影响,我们将相隔一定距离的两股黑白复丝从前罗拉后方喂入加捻卷绕机构来模拟双纱纺纱过程,并利用高速照相对纺纱过程中的纱线进行动态摄影,分析了一些主要纺纱工艺参数对纺纱过程和纺捻线性能的影响。     

喷气纺纱成纱机理研究

从50年代末美国 Du Pont 公司提出利用缠绕方法纺纱到现在,喷气纺纱在设备上得到了很大的发展。但是,对于这种纺纱方法的加捻与成纱机理的研究却是非常少的。本文提出了喷气纺纱过程中假捻区捻度形成的一种机理,可以用来解释单、双喷嘴情况下的捻度分布情况。通过对村田(孪生双喷嘴)及 Du Pont(单喷嘴)纺纱原理的对比研究,提出了包缠纤维的形成机理。分析表明,由于村田原理喷嘴的安排使第1喷嘴与前罗拉钳口之间纱线的自转与气圈回转的方向相反,推后了边缘纤维被纱线夹持的位置,使较多的边缘纤维有可能在纱线中成为有效的包缠纤维。进而阐述了喷气纱的特点:毛羽的单向性、包缠纤维及纱芯捻度的不均匀性、单、双喷嘴成纱条件和成纱质量的区别,主要纺纱参数对纱线强力的影响等。     

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.     

管道纺纱主要工艺参数的优化

管道纺纱是一种新研究出来的自由端纺纱方法,要能实际纺纱还必须合理地选择其工艺参数.本文分析了影响管道纺纱的主要工艺参数.采用二次旋转组合设计方法,通过实验,建立了主要工艺参数与成纱强力的数学模型,确定了相应的约束条件.并采用惩罚函数法进行优化计算,求得最佳工艺条件.再根据优化计算出来的工艺条件,在管道纺纱单头试验机上实际纺制28tex纯棉纱.不仅能稳定地纺纱,而且其纱强力与优化计算结果基本一致.     

摩擦—喷气复合纺纱主要工艺参数的优化

分析了影响摩擦—喷气复合纺纱的主要工艺参数。采用二次旋转组合设计方法,通过实验建立了主要工艺参数与成纱强力的数学模型。并采用惩罚函数法进行优化计算,求得最佳工艺条件,根据优化工艺条件,在摩擦—喷气复合纺纱试验机上实际纺制32tex纯棉纱,纱的实测强力与理论结果基本一致,达到同类环锭纱的80％以上。     

Richcel纤维转杯纱的工艺特征及纺纱性能分析

介绍Richcel纤维的基本技术性能,对Richcel纤维转杯纺纱工艺特征和纺纱性能进行了分析,并通过Richcel纤维与棉混纺,确立了Richcel纤维与棉纤维混纺转杯纱的工艺流程和主要工艺参数,使设计的Rich-cel纤维转杯纱达到了较理想的质量要求.为规模生产Richcel纤维转杯纱积累了经验.     

喷气纺纱工艺参数的优化选择

从优化喷气纱性能入手，通过确定目标值域，对喷气纺纱的主要工艺参数进行了试纺优选，找出了达到目标值域的优选参数。对于实际生产，有一定指导意义。     

棉/涤纶长丝Sirofil复合纱成纱工艺性能研究

以低弹涤纶长丝和精梳纯棉粗纱为原料,纺制不同捻度、不同喂入间距、不同长丝预张力的Sirofil复合纱,并测试了纱线的强力、条干和毛羽.通过正交试验分析方法,得到实验范围内棉/涤纶长丝Sirofil复合纱的优化纺纱工艺参数为捻系数321,长丝须条间距6mm,长丝张力片重量3g.     

转杯纺纯棉竹节纱的工艺探讨

通过在BD200SN转杯纺纱机上加装伺服驱动自控系统,控制纤维喂入量来改变牵伸倍数的方式实现纺制转杯纺纯棉竹节纱.通过工艺实验,分析了纤维性能、纺纱工艺等因素对转杯纺纯棉竹节纱质量的影响,探讨了生产转杯纺纯棉竹节纱的工艺措施,纺制了符合质量要求的转杯纯棉竹节纱.     

TENSILE BEHAVIOUR OF ROTOR SPUN YARNS

This paper deals with the tensile behaviour of rotor spun yarns. Having regard to the spe-cial construction of rotor spun yarn, some modifications for Hearle's theory have been made inorder to apply Hearle' s theory to rotor spun yarn. The paper then goes into calculating thetensile curve and investigating the effect of main parameters and spinning conditions on thetensile behaviour of rotor spun yarn. It was found that the following facts are noteworthy forimproving the mechanical properties of rotor spun yarn: (1) Selecting suitable navel so as tocontrol the P. T. E. length within a reasonable range. (2) Improving the design of single fibresupply device to decrease the amount of spoiled fibre and hence increase the effective fibrelength. (3) Increasing spinning yarn tension without yarn break to enhance the fibre migrationratio. (4) For the rotor spun yarn of industrial use, it is the way to increase the yarn strengththat the rotor groove should be designed with the groove angle beneficial to decrease the yarnspecific volume.     

REPORT ON A PROJECT AIMED AT INCREASING THE STRENGTH OF FRICTION SPUN YARN BY USING A FALSE TWIST PROCESS

The lower strength of friction spun yarns has became a key problem that hinder the develop-ment of friction spinning,especially in high speeds and fine yarns.In this paper a project aimed atincreasing the strength of friction spun yarns by using a false twist process has been made.In re-ported experiment false twist was inserted into the yarn which has been formed on a friction spin-ning machine,so that it made the yarn untwist at first,then regain the twist.In the meantime draftwas applied to generate more tension than that which had been experienced during yarn formationon the friction spinning machine.It made the yarn reforming and the loosely bound fibres in thefriction spun yarn formed due to extremely low tension on the friction spinning machine becametighter.Results indicate that with the proper draft,tension and false twist the tenacity of processedyarn will increase more than 10%.This project is an attempt to discover whether improvements can be made and whether it isworth pursuing research into modifications of yarn structure.The results imply that if the yarntension can be raised during yarn formation on the friction spinning machine or a chance is offeredto the yarn to reform after the yarn formation the yarn tenacity will be increased obviously.     

Characterizing and Analyzing the Airflow Field inside the Nozzle Block of Murata Vortex Spinning

A three-dimensional computational fluid dynamics model is developed by software Fluent 6.2, to simulate the flow field inside the nozzle block of the Murata vortex spinning. The flowing state and the distribution law of static pressure and velocity are characterized and analyzed. The relationship between the flowing state and the structure of the vortex spun yarn is also discussed. The research results can enhance the understanding of the yarn formation principle from viewpoint of the airflow field law inside the nozzle block of Murata vortex spinning.     

摩擦－喷气复合纺成纱结构的研究

从理论和实际上论述了摩擦－喷气复合纺纱的加捻过程，并利用电子显微镜和示踪纤维方法对摩擦－喷气复合纱和色芯摩擦纺分别进行了分析和测量，发现摩擦－喷气复合纱的芯纱比包芯摩擦纱的芯纱具有较多的包缠纤维和较高的包缠捻度，表明摩擦－喷气复合纺纱有利于提高成纱强力．     

杠杆补偿式张力器的分析及其在气流凝聚包芯纺纱中的应用

杠杆补偿式张力器是一种具有自行调节补偿能力的张力装置.本文从静力和动力两个方面对它的特性进行了分析和讨论,并将其应用于气流凝聚包芯纺纱中作芯丝的张力装置.由实验知,当输入张力在一定范围内变化时,该张力器的输出张力能基本保持恒定,从而满足了工艺的要求.     

气流纱的拉伸特性研究

本文讨论气流纱的拉伸特性。Hearle曾对具有理想结构纱线的拉伸特性进行过比较完整的研究工作。本文则根据气流纱独特的成纱结构,对Hearle理论在气流纱中的应用作了一定的修正,并在此基础上对气流纱的拉伸特性作了分析计算。计算结果与实测结果基本相符。最后还从气流纱的应力-应变关系式中,就影响气流纱强力、初始模量以及断裂功等等力学特性的一些主要工艺参数进行了分析讨论。得出合理选用阻捻盘、很好控制捻度传递长度;合理设计与选用分梳及输棉机构,在不断改善单纤维供应的同时,尽量减少纤维损伤,提高纤维有效长度;适当提高纺纱张力,增加纤维转移等等都是改善气流纱强力等力学特性、提高成纱质量的有效途径。对工业用气流纱,还可通过合理设计凝棉槽,以提高气流纱紧密度的途径来提高气流纱强力。     

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.     

低档兔毛纺纱工艺路线探索

低档兔毛纤维短,本文采用棉型纺纱系统,可以纺制18 tex以细的纱,这样有利于开发薄型产品。但纯兔毛纱强力较小,可用涤丝包芯方式采加固。产品经济实惠,适合内销市场需要。本文工艺采用短流程,基本上在棉纺设备上加以改装后纺制成纱。