Characterization of needle-punched nonwoven fabrics for industrial air filter application

Needle-punched nonwoven fabrics with three different areal weights have been developed using micro-denier (0.8 Denier) and fine-denier (3 and 6 Denier) staple polyester fibers, separately. Process parameters such as punching density and depth of penetration have been changed according to the fabric areal weight. Effect of fiber fineness and areal weight on air permeability, tensile strength, bursting strength and compressibility of the fabric has been analyzed. It has been observed that air permeability decreases with the increase in areal weight of the nonwoven. The micro-denier fiber nonwoven gives 40% lower air permeability as compared with fine-denier fabrics. 6 Denier nonwoven provides 44% higher tensile strength as compared to 0.8 Denier nonwoven fabric and 23% higher tensile strength than 3 Denier fabrics. Compressibility and compression recovery of 6 Denier fabrics are also better as compared with other fabrics. However, micro-denier fabric shows 24% improvement in bursting strength and very good air dust filtration efficiency.     

棉及棉麻混纺织物的服用性能研究

以纯棉纱、黄麻/棉混纺纱为原料,采用相同的上机工艺参数,分别试织了纯棉及两种配比的黄麻/棉混纺织物,对3种织物进行了吸放湿性能、芯吸效果、拉伸性能、透气效果、悬垂性、折皱回复性及织物风格等方面的测试与比较。研究结果表明:用18texJ30/C70纱制织的织物的拉伸断裂强力及撕破强力与棉织物基本接近,两种棉麻混纺织物相对纯棉织物均具有更为优良的吸湿性能、芯吸性能及透气性能,弯曲刚度大于纯棉织物,而折皱回复性及织物悬垂性差于纯棉织物。     

混纺比对竹炭改性涤纶纤维/棉混纺针织物性能的影响

为了研究竹炭改性涤纶纤维/棉混纺针织物的性能,对5种不同混纺比例的竹炭改性涤纶/棉混纺针织物的各种性能进行了测试分析。结果表明,随着竹炭改性涤纶纤维含量的增加,混纺针织物的断裂强力下降,断裂伸长率下降,顶破强力逐渐下降,纵向、横向弯曲长度和织物的硬挺系数逐渐下降,柔软性提高,悬垂性和保暖性越来越好。     

经编贾卡提花间隔织物的顶破性能

为探讨不同经编提花间隔织物结构的顶破性能差异,采用在拉舍尔双针床贾卡经编机上编织的8种不同提花结构的织物进行顶破性能试验,分析不同织物的顶破强力大小和顶破曲线特征,解释了经编间隔织物的顶破机制,并从提花面结构角度讨论对织物顶破强力的影响。结果表明：平布层和提花层分别影响间隔织物顶破过程的第1、2阶段;间隔层结构决定间隔织物顶破高度;提花面结构决定间隔织物顶破强力大小,厚组织顶破强力大于薄组织,顶破强力与网孔尺寸成反比关系;在鞋用经编提花间隔织物的设计中,可根据鞋面部位和功能需求进行灵活的组织搭配,丰富鞋材的花纹图案。     

Theoretical and experimental investigation of tensile properties of net warp-knitted spacer fabrics

Abstract

This work aimed to investigate the tensile behavior of net warp-knitted spacer fabrics using the experimental and theoretical approaches. Tensile behavior of the warp-knitted spacer fabrics is one of the fundamental parameters which rarely considered in the literature. Therefore, the net spacer fabrics were made with three different variables (fabric thickness, size of meshes, and the position of meshes of the outer layer with respect to each other) in order to study the effects of structural parameters on the tensile behavior. A 2D net-fabric which used for the outer fabrics was made for in-depth considerations and also the comparison between the 2D fabrics and spacer fabrics. The initial linear elastic modulus of the 2D fabrics and the initial linear elastic modulus of the spacer fabrics were selected for the assessment of the tensile characteristics. First, a mechanical model was developed based on the geometrical structures and material properties of the 2D fabrics using energy method and Castigliano’s theorem. Then, the effects of spacer yarns on the tensile behavior of spacer fabrics were taken into account. The latter model was proposed using the bending theory of a curved bar. Experimental data were compared with the values obtained from the theoretical approaches and the end results showed that the developed models can predict the modulus reasonably. Moreover, the results indicated that the tensile behavior of the spacer fabrics are independent of the position of the holes in the outer layer whilst the fabric thickness and size of meshes affect the tensile modulus.     

蜂巢棉织物力学性能的测试与分析

为使蜂巢组织类织物在增强复合材料中得到更合理的应用,采用相同的原料和经纬密度织制不同蜂巢类组织织物,并对织物的拉伸强度、撕裂强度和顶破强度进行测试,分析不同蜂巢组织对其织物力学性能的影响。结果表明:在织物原料和经纬密度相同的情况下,不同蜂巢组织的织物其力学性能有明显的不同;纱线的交织次数越多,蜂窝越小,织物的断裂强力越大;而织物断裂伸长率、撕裂强力和顶破强力随着蜂窝尺寸的变小,先增加后减少。     

Development and characterisation of polyaniline/polyamide (PANI/PA) fabrics for electromagnetic shielding

In this study, novel conductive fabrics were developed by polymerising of aniline onto the polyamide (PA)-knitted fabrics. The fabric treatment was done by the chemical polymerisation method at 0.5, 0.8 and 1.2?M aniline concentrations. Hydrochloric acid as acidic medium and ammonium per sulphate as oxidant were employed during the polymerisation process. The polyaniline (PANI)-treated PA fabric structures were fully characterised and evaluated in terms of their electromagnetic shielding effectiveness, absorption and reflection characteristics and tensile properties. Additionally, the fabrics were examined by scanning electron microscope (SEM) for the surface morphology and Fourier transform infrared spectroscopy for the chemical functionality. The electromagnetic shielding effectiveness, absorption and reflection characteristics were determined by Network Analyzer with a frequency ranged from 15 to 3000 MHz. The electrical characteristics were measured by the two ends method. It has been concluded that the bursting strength values of the treated fabrics reduced when the amount of monomer in the concentrations decreased as compared to the untreated fabrics. It is interesting to note that 1.2 M treated fabric had the highest bursting strength values as compared to the other treated fabrics. It was also found that 0.5 M concentration of PANI-treated fabric had the lowest surface resistivity due to this it showed the highest conductivity value. Another important finding is that the 0.5 M-aniline treated fabric had the highest shielding effectiveness.     

Interface treatment and performance study on fiber tube reinforced polyvinylidene fluoride hollow fiber membranes

Abstract

The fiber tube reinforced hollow fiber membranes are widely used in membrane bioreactor (MBR) due to their excellent mechanical and filtered properties. However, the poor adhesive power between fiber tubes and membranes restricted their service life in practice applications. Herein, we supply a facile and feasible surface coating modification methods for optimizing the interfacial bonding ability. The outer surfaces of the braided and knitted tubes were modified with silane coupling agent KH570 and acrylate adhesive before the fiber tube reinforced hollow fiber membranes were fabricated. The effects of different modifiers dosages on the morphology, tensile strength, bursting strength, pure water flux, porosity and mean pore size of the braided and knitted tubes reinforced hollow fiber membranes were evaluated respectively. Moreover, the effects of different modifiers on the fabric tubes with different structure were analysed. The results showed that the optimum dosage of the two modifiers was 3?g/5m. It is revealed that the minute quantities of modifiers applied to the tubes could improve not only the interfacial combination of the reinforced membrane, but also their strength and penetration performance.     

聚偏二氟乙烯（PVDF）经编疝修补片的力学性能研究

无张力疝修补是当前治疗疝气的主要手术方式,研究和应用最多的手术用修补材料是聚丙烯（PP）补片。近期有研究表明,聚偏二氟乙烯（PVDF）是一种理想的替代PP的补片材料。采用PVDF单丝,选择三针开口经缎结构和热定型工艺,制备了PVDF疝修补片,测试了该补片的硬挺性、拉脱性、拉伸性、弹性回复性及顶破性等力学性能,试验结果显示该补片具有良好的力学性能。     

柔洁纺粘胶强捻纱及其织物性能

为更好地探究柔洁纺技术对粘胶强捻纱质量和其机织物服用性能的影响,对相同工艺参数下粘胶强捻柔洁纺纱线与环锭纺纱线的均匀度、毛羽、单纱强力、捻缩率和表观结构进行测试对比,同时分析了相同规格柔洁纺和环锭纺粘胶强捻纱织物的强伸性、顶破性能、撕破性能、透气透湿性、吸湿性、柔软性和抗起毛起球性能。结果表明:柔洁纺粘胶强捻纱的毛羽少,条干均匀,强力高,捻缩率低;相比环锭纺粘胶强捻纱织物,柔洁纺粘胶强捻纱机织物的强伸性、顶破性能、撕破性能、透气透湿性、柔软性和抗起毛起球性显著提高,但吸湿性有所降低;柔洁纺粘胶强捻纱具有柔顺、整洁、牢固等特点,其机织物的综合服用性能优于环锭纺。     

Introducing and optimizing a novel mesh for simulating knitted fabric

In this paper, a mass spring system is developed to simulate the draping behavior of knitted fabric. A new type of mesh based on loop structure, which is called Loop mesh, is introduced. The effective properties on fabric drape are measured using the Fast system, and the experimental data are incorporated into the mass spring model to simulate the draping behavior of knitted fabrics. 3D shape of real drape behavior of fabric samples is achieved using depth camera. Then in order to reduce error value between simulated and real results, distances between mass points in the Loop mesh are optimized using the Imperialistic Competitive Algorithm (ICA). In order to investigate validity and accuracy of the Loop mesh, drape behavior of knitted fabrics falling over a square table are also simulated using common meshes. It can be found that the Loop mesh produced a closest drape shape to the real fabric drape than other mesh models. Finally, fabrics drape is simulated in other situations and compared with its real result to validate the proposed model. Results show that the optimized model is able to simulate the drape behavior of knitted fabric with error value of 4.29 percent.     

球形天线球面材料的力学性能研究

为研究球形天线球面材料所需具备的力学性能,在标准试验室环境中对TPU涂层高强涤纶机织布进行单向拉伸、抗撕裂及顶破等力学性能测试,并测试2种拼接方式对球形天线球面材料单向拉伸性能的影响,以及TPU涂层高强涤纶机织布经质量分数皆为20%的盐酸和氢氧化钠溶液腐蚀后的单向拉伸性能。结果表明:TPU涂层高强涤纶机织布经向拉伸断裂强力大于纬向;曲面拼接的球形天线球面材料的拉伸断裂强力大于平面拼接的球形天线球面材料;TPU涂层高强涤纶机织布耐碱蚀性能优于耐酸蚀性能。     

室外环境下涤纶织物的性能变化

将涤纶织物暴露于室外环境下处理,测试处理前后涤纶织物透气性、透水性、颜色特征值、光泽度、拉伸性能、撕裂强力、顶破强力、耐磨性、硬挺度等性能的变化情况,采用扫描电子显微镜观察处理前后纤维表面形貌.结果表明:涤纶织物长期暴露于室外环境下会产生老化现象,尤其是超过8个月后,老化现象明显,从而影响涤纶织物的使用寿命.因此,在以涤纶为材料的室外产品设计时应充分考虑这一现象,以免产生不必要的损失.     

Reactive dyeing of a pretreated jute fabric using minimum application technology

Abstract

Grey jute fabrics were given pretreatment such as scouring which was followed by enzyme treatment. These pretreated jute fabrics were subsequently bleached with hydrogen peroxide. Dyeing of these bleached jute fabrics was carried out with four different classes of reactive dyes, namely cold- brand, hot-brand, vinyl sulphone and HE-brand reactive dyes, following the conventional exhaust method and pad-batch method, i.e. minimum application technology method. With respect to dyeing behaviour, it was found that dye uptake and wash fastness property of a dyed fabric produced by the pad-batch method is well comparable with that produced by the conventional exhaust method. Irrespective of the methods of dyeing, scoured–bleached and scoured–enzyme treated–bleached jute fabrics show better dye uptake and fastness property compared to grey-bleached fabrics. Weight loss and strength loss increase while bending length decreases with the increase in pretreatment stages. Enzyme treatment of a scoured jute fabric before bleaching produces the minimum bending length among all the samples. The pretreatment process is found to have some detrimental effect on the tensile properties of a jute fabric and as the number of pretreatment steps increases, the tenacity of the fabric decreases. Reactive dyeing of pretreated jute fabrics further reduces their tensile strength by around 10% irrespective of the method of dyeing and the pretreatment process. So, minimum application technology can be well adopted for dyeing of a jute fabric with reactive dyes. The process is simple, cost effective as it utilises dye to its maximum extent, requires minimum energy and is suitable for use in cottage and small-scale industries.     

Air permeability and bursting strength of weft-knitted fabrics from glass yarn. Part I: cam setting and number of yarn ply effect

This study revealed the effect of cam setting and number of yarn ply on air permeability and bursting strength of weft-knitted fabrics from glass yarn. Change in cam setting from loose to tight level increased fiber content, and stitch-density; while it decreased loop length. Fabrics with 3-ply yarn exhibited higher fiber content; lower stitch-density; and longer loop length than fabrics with 2-ply yarn. Cam setting showed more pronounced effect on physical properties of fabric than number of yarn ply. Fabrics knitted via tight cam setting level exhibited less air permeability, and higher bursting strength than fabrics knitted via loose cam setting. Fabrics from 3-ply yarn showed less air permeability and higher bursting strength than fabrics from 2-ply yarn. Loop length, wale density, and fiber content were determined as the most effective physical properties on permeability and bursting strength. A negative correlation was detected between air permeability and bursting strength.     

A review on fabric bagging: the concept and measurement methods

Fabric bagging is a three-dimensional permanent deformation which can deteriorate aesthetical appearance and mechanical properties of garments. This review presents a brief look at the concept of bagging deformation consisting basic definitions, theories and modelling, objective and subjective evaluation and the parameters affecting fabric bagging. The effects of both fabric structural properties and bagging test parameters have been also explored. A thorough knowledge of bagging measurement by different laboratory tests such as unidirectional tensile, bursting strength, ball penetration tests and devices resembling an arm having an elbow point for simulating human movements in static or dynamic conditions was reviewed in details.     

无捻纱织物的性能分析

对无捻纱针织物的透气性、吸湿性、缩率等进行测试,并与有捻纱针织物的相应指标进行对比。无捻纱针织物的透气性几乎是传统棉针织物的2倍,说明无捻纱针织物有良好的透气性能。无捻纱针织物的干燥速度要比普通的棉针织物快,说明无捻纱针织物的水分散失能力比普通棉针织物好。同时对无捻纱机织物的透气和透湿性能、拉伸性能、顶破性能、悬垂性等进行测试,证明无捻纱织物具有良好的服用性能与开发前景。     

含水凝胶夹层保湿袜的制备及性能研究

采用71.4 tex美利奴羊毛与低起球腈纶混纺纱(50∶50)和76.9 tex仿腈纶毛羽纱,在岛精SWG061N型电脑横机上分别编织纬平针织物,然后通过钩编方式将两种织物结合。采用普鲁兰多糖与γ-聚谷氨酸制备水凝胶并包覆在两层织物中,设计一款具有保湿护肤功能的针织袜,并测试织物的拉伸断裂性能、弹性回复率、顶破强力、透气性、透湿性。结果表明,在相同条件下,复合织物的顶破强力比单层织物提高了至少19.0%,但透湿能力下降,加入水凝胶后,织物透湿率下降超过40.0%,透气率下降超过20.0%,通过加入水凝胶可制备兼具力学性能和保湿性能的袜品。     

木素磺酸钠作为添加剂的研究

研究了木素磺酸钠作为一种添加剂加入到针叶木浆中对纸张的性能的影响.结果表明:木素磺酸钠可以增加纸页的施胶度、平滑度、耐破度、耐折度、抗张强度及不透明度,对撕裂度影响不大,但白度、透气度下降.     

棉/单芯涤纶长丝包芯纱织物的力学性能研究

文章对棉/单芯涤纶长丝包芯纱织物的力学性能指标进行了测试分析与比较,其断裂强度和撕裂强度均高于同规格纯棉环锭纱织物,经向的拉伸强度和撕裂强度比纬向的要大,而顶破性能则比纯棉环锭纱织物差。