经编针织物双向拉伸性能研究

测试了5种经编针织物的双向拉伸性能,考察了拉伸方向、拉伸速率及织物结构对拉伸性能的影响。当织物结构相同且一个方向固定、另一个方向拉伸时,横向拉伸的断裂强力与断裂伸长大于纵向拉伸的。随着拉伸速率提高,织物的断裂强力与断裂伸长先增大后减小。当织物组织结构与参数相近时,双向拉伸的各项指标相差不大。单梳经绒织物的断裂伸长比经绒平、经平绒、菱形及四角网孔4种双梳织物的大。     

Multi-response optimization of mechanical and comfort properties of bi-stretch woven fabrics using grey relational analysis in Taguchi method

The present paper envisages the multi-response optimization of certain factors like elastane linear density, fabric thread density and weave float on some mechanical, (i.e. stretch %, recovery %) and comfort (i.e. air permeability) properties of bi-stretch woven fabrics, under L₁₈ orthogonal array in Taguchi design. Fabric samples were produced using elastane core-spun cotton yarns both in the warp and weft. The elastane linear density, fabric thread density and weave float size were used as predictor variables, while fabric air permeability, stretch and recovery were taken as response variables. Two different elastane linear densities, i.e. 44 dtex and 78 dtex, 3 different thread densities and 3 different weave designs, i.e. 1/1 plain, 2/2 z-twill and 3/3 z-twill were used. The results have been analysed using grey relational analysis for the identification of an optimum level of process factors. Furthermore, using analysis of variance method, significant contributions of predictor variables were determined.     

Microstructural transformations in anisotropy and melt-stretch properties of low moisture part skim mozzarella cheese

Mozzarella cheese is primarily consumed in its melted form due to its desirable melt and stretch characteristics when heated. Understanding the relationship between the anisotropic structure and melt-stretch properties is critical for controlling functionality. A novel ex situ sample extraction system was developed to produce melted and stretched mozzarella. New structure analytics were established to reveal transient changes during deformation of mozzarella under dynamic heat-shear conditions. Transformations in anisotropy were examined using various microscopy techniques coupled with image analysis. Coalescence of milk fat aggregates into large droplets upon heating caused loss of anisotropy. However, fat droplets broke down into channels on stretching, comprising agglomerates of smaller droplets, and anisotropy was regained. When stretched further, adhesion between agglomerated fat droplets was broken by forces exerted from the contracted protein fibres. Large fat droplets are necessary as they act as shock absorbers that enable protein fibres to become pliable, allowing greater stretch.     

机织物透气性能的预测研究

利用哈根伯肃叶定律,推导出机织物的纱线间孔隙透气量与织物结构参数的关系式。对于无法从理论上阐明的影响因素用逐步回归方法讨论它们的定量影响,得到织物透气量与纱线间孔隙透气量的理论计算值及织物紧度间的回归方程,并用新的试样验证此公式的准确性。     

几种不同组织结构的衬衫面料保形性研究

根据常见的衬衫面料组织结构,使用JC9.7 tex纱线设计了6种不同组织结构的面料,研究不同组织结构对织物保形性的影响。对面料的保形性(尺寸稳定性、抗折皱性、外观平整度、抗起毛起球性、顶破性、悬垂性)及舒适性(透气、透湿性)进行了测试。结果表明:组织结构对织物的折皱回复角、外观平整度等级、顶破强力、透湿量与透气率有直接影响;织物紧度太大、太小都不利于织物的折皱回复,相同紧度下斜纹组织的抗皱性比平纹好;6种组织结构中2/2斜纹组织抗折皱性最好,2/2方平组织的顶破强力、抗起毛起球等级最高,2/2破斜纹透气、透湿性最好,2/2斜纹组织具有良好的保形性。     

Air permeability of multilayer woven fabric systems

A model to predict the air permeability of a multilayer woven fabric system from the air permeability and construction parameters of a single fabric has been developed. A new factor to account for the distortion of the threads in the fabric due to the flow of air through the layers of the fabric is proposed. This model incorporates the fabric cover factor (determined using an image‐processing method) and the proposed distortion factor (determined based on yarn linear density and fabric structure). The performance of the proposed model has been successfully validated by using it to predict the air permeability of other multilayer woven fabric systems and comparing it to experimentally determined values. The model can thus be used as a valuable tool in the engineering design of multilayer woven structures with desired air permeability performance requirements.     

织物电极监测心电信号与穿戴压力作用机制分析

为探索穿戴压力对纺织结构心电电极采集心电图(ECG)信号质量的影响,开发了基于镀银锦纶丝束和涤纶的平纹和缎纹交织结构的4种导电织物电极。从皮肤-电极接触阻抗、舒适性以及织物方阻与穿戴压力的关系等方面评价了织物电极的性能,并测试了不同穿戴压力(2、5、10 kPa)下4种不同织物电极采集ECG信号的性能。结果表明:在不同穿戴压力下,不同结构的织物电极表现出不同的ECG信号采集能力和舒适性能;随着穿戴压力增加,所测试的导电织物方阻先呈下降趋势,然后趋于稳定,ECG信号质量不断增高;纯导电缎纹结构织物具有更好的透气透湿性,并且舒适性优于平纹结构织物;然而在舒适的穿戴压力(2、5 kPa)下,平纹结构织物电极表现出更好的ECG信号质量。     

羊毛与37.5涤纶混纺针织物的热湿舒适性研究

选择8种不同的羊毛与普通涤纶、37.5涤纶混纺针织物试样,测试试样的密度、面密度、未充满系数和厚度等基本参数,以及回潮率、透气率、芯吸高度、瞬间接触凉感(Q-max)及恒定加热条件下的干、湿态升温性能等织物的热湿舒适性能,分析和评价了针织物的基本参数对其热湿舒适性能的影响。试验结果显示,与普通涤纶相比,采用37.5涤纶有助于提高织物的回潮率、芯吸高度和Q-max;透气率随针织物未充满系数的增大而增大;当织物的纤维组成成分基本一致,组织结构相同时,针织物的面密度越大,透气性越差;含37.5涤纶的纬平针织物的瞬间接触凉感性能较好。     

BP神经网络预测降落伞绸透气性的研究

透气性是降落伞绸的重要性能指标。降落伞绸织物的纱线线密度和织物密度、厚度、面密度及织物组织等结构参数与其透气量存在非线性的关系,由于织物结构各参数间的非线性关系及多个影响因素共同对织物的透气性能的作用,织物结构参数与其透气性能之间很难用传统数学、力学的方法来描述。人工神经网络能够处理复杂的非线性关系。本课题研究了利用人工神经网络来预测降落伞绸织物的透气性能,以期代替传统的测试方法,从而在新品种设计时对织物的参数设定提供指导。     

针刺非织造布渗透性能的探讨

针对针刺非织造布的结构探讨了其渗透机理，并通过非织造布透气性，透水性及在不同法向压力下渗透系数的测试，分析了透气性与透水性的相互关系及法向压力对针刺非织造布渗透性能的影响。     

28—THE PRODUCTION OF WEFT-STRETCH COTTON FABRICS BY SLACK MERCERIZATTON

In the production of weft-stretch fabrics by slack mercerization, weft shrinkage was assisted by the application of high warp tension during mercerization and washing. The addition of a polyethylene lubricant to the post-mercerization resin bath reduced the warp stiffness of the fabric and slightly improved its stretch, performance. At specific warp and weft cover factors, plain weave gave a better stretch performance than twill weaves, although the differences were less than expected. The choice of finer weft than warp yarn facilitated the development of weft crimp. Unless the weft yarn spacing was adequate, however, the weft crimp could not be fully utilized on stretching, because of jamming of the fabric structure during crimp interchange.     

聚乙烯针织物的热湿舒适性能

为研究织物结构参数对聚乙烯针织物热湿舒适性能的影响,选取3种规格的聚乙烯长丝织成双罗纹针织物,并选用涤纶、凉感涤纶长丝制备相同结构双罗纹织物作为对比试样,研究构成织物的原料种类、未充满系数、捻度对织物孔隙率、透气性、导热及导湿性能的影响。结果表明:在织物结构相同的情况下,构成织物的原料、未充满系数与织物透气、导湿、导热等热湿舒适性能显著相关;纱线捻度与织物的导热及导湿性能显著相关;与涤纶、凉感涤纶织物相比,聚乙烯长丝表面存在沟壑,结晶度、取向度较高,其织物具有优良的透气、导湿和导热性能,是制备凉爽舒适功能纺织品良好原材料。     

机织物透气性预测的投影寻踪回归模型

针对机织物透气性预测中存在非线性建模困难的问题,选择机织物总紧度、厚度、面密度及平均浮长等结构参数作为机织物透气性预测的影响因素,建立机织物透气性预测的投影寻踪回归模型.对模型训练样本的拟合值及检验样本的预测值以相对误差的均值及标准差为指标进行分析,并与BP神经网络及多元线性回归模型进行对比.结果表明,投影寻踪回归模型...     

The effect of moisture and air gap on the thermal protective performance of fabric assemblies used by wildland firefighters

The thermal protection performance (TPP) provided by fabric assemblies used by wildland firefighters is greatly affected by both the moisture and the air gap trapped in multilayer fabrics. In this paper, the effect of moisture, coupled with air gap on TPP was analyzed under radiant heat exposures of 21 kW/m². The air gap sizes from 0 to 5.2 mm were analyzed using an air gap height regulation device; the moisture content of the multilayer fabric combinations around 0–70% were obtained by spraying distilled water to simulate varying amounts of sweat absorption. The results obtained indicate that certain air gaps entrapped in multilayer fabric system have a positive effect on TPP for both dry and wet multilayer fabric combinations. However, obvious trend changes in thermal protection were observed among dry and wet configurations when the air gap was moved to different positions. For the wet configurations, the second-degree burn time increased as the air gap moved further from the heat source, which was contrary to burn time response under dry conditions. These findings suggest that the complicated reciprocal effect of air gap and moisture on thermal protection should be both considered in analyzing the TPP of fabric assemblies.     

SmartStretch™ technology. II. Improving the tenderness of leg meat from sheep using a meat stretching device

This study evaluated the effect of stretching hot-boned sheep hindlegs from 40 sheep carcases, classified as mutton, using a prototype device (SmartStretch™). Left and right legs were collected pre-rigor and randomly allocated to one of four treatments; 0 days ageing + SmartStretch™, 0 days ageing + no stretch, 5 days ageing + SmartStretch™ and 5 days ageing + no stretch. There was a significant interaction between stretch treatment and ageing (P < 0.05) for shear force of the m. biceps femoris such that stretched and aged samples were the most tender. By contrast stretched m. semimembranosus (SM) had a significantly (P < 0.05) lower shear force only at 0 days of ageing. Stretching produced longer sarcomeres (P < 0.001) for both the SM and m. semitendinosus muscles. Myofibrillar degradation indicated by particle size analysis or histology was not affected by stretching, but there was an ageing effect (P < 0.001). SmartStretch™ provided significant improvements in tenderness of the individual muscles.     

Effect of structural parameters on thermal protective performance and comfort characteristic of fabrics

In an attempt to understand the influence of basic structural parameters of fabrics on thermal protection and comfort, present study mainly focuses on analyzing effect of fabric weaving pattern and fabric weight. Fabric samples of three basic weaving patterns (plain, twill, and satin) and three different weights were prepared. Air permeability of the developed fabric samples was measured. Thermal protective performance of fabrics against radiant heat and flame exposures of two different intensities were measured. Spectral transmission behavior of fabrics was also studied. It was observed that for same fabric weight, protective performance and air permeability of satin woven fabrics were better as compared to the fabrics of other patterns. Protective performance increased and air permeability decreased as fabric weight increased for each type of woven structure included in this study. A new structural parameter is proposed which primarily influences the protective performance of fabrics exposed to either radiant heat, flame, or combined convective/radiant heat exposure.     

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.     

超细中长大豆蛋白纤维性能及其混纺产品风格

基于对超细中长大豆蛋白纤维的力学、电学、吸湿、热学等物理性能的实验研究,应用MATLAB软件对相关实验数据进行曲线拟合,探讨了超细中长大豆蛋白纤维与超细棉型涤纶混纺产品的纺织工艺;研究了漂白织物在可见光谱下的反射和吸收性能及织物在低负荷下的拉伸、抗弯、折皱回复性、吸湿透气等综合风格,为大豆蛋白纤维的性能改进及产品开发提供了借鉴。     

织物组织对服用舒适性能的影响

研究织物组织对服用舒适性能的影响。在其他结构参数均相同的条件下,测试了4组不同组织织物的保暖率、透湿量、透气率、抗弯刚度和折痕回复角,并运用灰色关联分析法得出这5个性能参数与织物厚度、浮长线长度和单位面积质量3个结构参数的关联度。结果表明:厚度对织物舒适性能的影响较显著,其次是单位面积质量和浮长线长度。指出:在织物原料和经纬密相同的条件下,可通过选择较厚的织物来提高织物的保暖率、透湿量、透气率和折皱回复性。     

Total porosity,theoretical analysis,and prediction of the air permeability of woven fabrics

Air permeability is one of the most important properties of textile materials that ensure their comfort. For many materials for technical applications (filters, sails, vacuum cleaners, parachutes, etc.), this is one of the main properties that determine their quality. The air permeability of woven textile fabrics depends on many parameters of fabric. Thus, the determination of air permeability of woven fabric is highly complex and difficult. In this study, we attempted to establish a theoretical model for the porosity and predicted the air permeability of woven fabrics. A theoretical model was created to predict the total porosity and the air permeability of a fabric structure depending on the geometrical parameters such as pore size, warp density, weft density, fabric thickness, number of yarn, diameter of yarn, and fiber density. For the purpose, a theoretical model of porous systems on D’Arcy’s law was used, and the validity of the model was confirmed by experimental results using 100% cotton and 97/3 cotton/lycra woven fabrics. Since the amount of air passing through both the pores between yarns and the interstices in the fibers constituting the yarn structure was calculated, theoretical values of air permeability were obtained very close to the experimental values.