A STUDY OF THE SPECIMEN SIZE OF STRIP TENSILE TEST FOR NEEDLE-PUNCHED NON-WOVEN GEOTEXTILES

In this paper,the failure features of strip tensile specimen were observed and analysed for need-le-punched non-woven geotextiles.A mechanical model which expresses the relation between thetensile modulus,the strip specimen size,contraction factor and the tensile strength of non-wovenfabric was derived.The theoretical prediction showed that the main factor influencing tensilestrength of non-woven geotextile specimens with different size is the contraction factor of specimenor the specimen aspect ratio(width/length).The larger the aspect ratio,the higher the tensilestrength test value of geotextiles,but the experiments showed that the specimen tensile strength isnot increased with increasing the width of specimen.The reason was discussed and it seemed thatthe deviation could be served as an indication of the degree of imperfectness of the non-wovenstructure.

High Oil-absorptive Composites Prepared from Non-woven Fiber and Sponges with 4-tert- butylstyrene-EPDM-divinylbenzene Graft Polymer

4-tert-butylstyrene-EPDM-divinylbenzene graft terpolymer (PBED) was prepared by graft cross-polymerization in toluene using BPO as an initiator. The gel-PBED and solPBED were isolated from extraction of tetrahydrofuran (THF), and then they were identified by IR spectroscopy. The maximum oil-absorptivity of gel-PBED produced from the optinum reaction conditions was 8 420% but its swelling rate was very low. The highest oil-absorptivity of photocrosslinked sol-PBED film was 5 800%. Although its oil absorbency was not as high as gel-PBED' s, swelling rate was higher than that of gelPBED and was suitable for commercial purpose. After swelling in oil, neither gel PBED nor photocrosslinked sol-PBED film having high oil-absorptivity had sufficient mechanical strength to be taken out of oil wholly. As is known, composite technique is one of the useful methods for reinforcing them. Fibers, sponges and non-woven cloths were used as reinforcers or supporters in this work. Oil-absorptivities and swelling kinetics were evaluated by method ASTM (F726 - 81 ) and an experimental equation. The mechanical properties and the morphologies of some composites were measured by tensile tester and SEM , respectively.

Preparation of UV-curable Nano-silver Antimicrobial Agent and Its Application in Non-woven Fabric

Nano-silver and waterborne polyurethane(WPU)composite emulsion was synthesized.The average diameter of silver nanoparticles(SNPs)was about 20 nm,and the average diameter of WPU was 101.32 nm.The anti-bacteria finishing of a polypropylene non-woven fabric(NWF)was carried out by ultraviolet finishing technology and the double dipping twin-roll method.The standard AATCC100 was used to test the antimicrobial activity of the samples.The results showed that the antimicrobial rates of Klebsiella pneumoniae(K.pneumoniae)and Staphylococcus aureus(S.aureus)were above 90%,which indicated that the NWF finishing had good antimicrobial activity.In addition,the thermal stability,mechanical properties,whiteness and contact angle of antimicrobial finishing nonwovens were characterized.The results showed that the performance of antimicrobial nonwovens was stable at 300℃.The breaking strength was better than that of untreated nonwovens,and the contact angle reached 119.1°.

Hygrothermal/UV Aging Effect on Visual Aspect and Mechanical Properties of Non-Woven Natural-Fiber Composites

This work aims at studying the effect of hygrothermal and UV cyclic aging on the tensile properties and esthetic characteristics of non-woven composites.The composite materials were thermo-compressed from non-woven mats made up of PP and flax or kenaf fibers.This works included evaluating the change in color appearance and analyzing the variations in tensile properties and damage mechanisms,depending on the aging time.The presence of the UV protection film on the composite surface showed its effectiveness against aging.From visual observations and measurement of colorimetric parameters,it has been proved effective in the reduction of the bleaching and yellowing of the composites.As regards the tensile tests,the UV protection film enabled to stabilize the Young’s modulus after 1-week aging for Kenaf/PP and after 3-weeks for Flax/PP.After 4-weeks aging,it halved the number of acoustic emission events related to interfacial decohesion and fiber slippage/pull out for Flax/PP and Kenaf/PP composites.

A Cell-Based Smoothed Finite Element Method for Modal Analysis of Non-Woven Fabrics

The combination of a 4-node quadrilateral mixed interpolation of tensorial components element(MITC4)and the cell-based smoothed finite element method(CSFEM)was formulated and implemented in this work for the analysis of free vibration and unidirectional buckling of shell structures.This formulation was applied to numerous numerical examples of non-woven fabrics.As CSFEM schemes do not require coordinate transformation,spurious modes and numerical instabilities are prevented using bilinear quadrilateral element subdivided into two,three and four smoothing cells.An improvement of the original CSFEM formulation was made regarding the calculation of outward unit normal vectors,which allowed to remove the integral operator in the strain smoothing operation.This procedure conducted both to the simplification of the developed formulation and the reduction of computational cost.A wide range of values for the thickness-to-length ratio and edge boundary conditions were analysed.The developed numerical model proved to overcome the shear locking phenomenon with success,revealing both reduced implementation effort and computational cost in comparison to the conventional FEM approach.The cell-based strain smoothing technique used in this work yields accurate results and generally attains higher convergence rate in energy at low computational cost.

Beijing Dayuan Non-woven Fabric Co.Ltd

Situated in the Shilong Industrial District of Mentougou, Beijing, the Beijing Dayuan Non-woven Fabric Co. Ltd is a Sino-foreign joint venture producing non-woven fabrics, set up in 1991.

Comparative Study of Polypropylene Non-Woven Surgical Mask and Locally Manufactured Woven and Knitted Fabrics Facial Masks

The outbreak of coronavirus has led to an increase in the demand for facemasks globally. Unavailability of appropriate polypropylene non-woven fabrics face masks as a result of inadequate supply to satisfy the growing population has brought about the manufacturing of locally fabrics masks to augment or substitute standard medical class facemasks. The study aims at analyzing airflow of these locally manufactured fabrics to determine possible means of transmitting the virus as well as establish comfort of the user of these masks. Standard polypropylene non-woven, woven and knitted fabrics were considered for the study. Air permeability test was conducted on these fabrics using Frazier Air permeability tester. Depending on the property significant variation in the textile fabrics, polypropylene non-woven is widely accepted for facial masks. Nevertheless, this study illustrates that woven and knitted fabrics have more open structures, which allow a high rate of air penetration and so may require two or three layers to prevent antimicrobial or antiviral potential.

Modelling the Influence of Air Jet Configurations on Non-Woven Steel Fibre Mixing in the Melt Overflow Process

The mixing of non-woven steel fibres in melt overflow process for use in automotive muffler systems was simulated. The aim was to identify optimum parameters for achieving a good fibre mix. Numerical models of mixing chambers of melt overflow process were developed. Multiphysics analyses involving heat transfer, fluid flow and particle tracking were carried out using COMSOL code. The influence of air jet configurations on the fibre distribution was studied. The fibres settled on the moving bed within the mixing chamber were examined for their uniformity. The effect of additional air jets to the existing chamber in a range of regions was explored. An optimum configuration was identified by analyzing the compactness of the particle clusters deposited in the simulation and validated using pixel data acquired from real time imaging. The results showed that by employing dual air jets at the front end of the chamber, the density of the fibre material has improved. We conclude that through multi-physics modelling, it was possible to identify the optimum air-jet configurations leading to fibre uniformity and its distribution. This work also paves the way for incorporating a vision system to evaluate fibre density in real time.

Cost analysis and comparison of plain cotton and disposable non-woven treatment towels

Objective: To choose a reasonably priced and low-cost treatment towel suitable for clinical application of hospital so as to reduce the cost of the hospital and make a reasonable use of resources through the cost analysis and comparison of the plain cotton and disposable non-woven treatment towels. Methods: The cost of the single pack plain cotton towel and disposable non-woven towel were analyzed and at the same time, 49185 packs of plain cotton towels which were the total consumption quantity of our hospital in 2017 and the same quantity of disposable non-woven towers were analyzed in the cost for comparison. Results:A single pack of disposable non-woven towel was RMB 2.50 cheaper than the plain cotton towel and the use of disposable non-woven towel can save the cost of RMB 2.50 per pack. In 2017, 49185 packs of plain cotton towel were used in total, which cost RMB 122962.50 less than the same quantity of disposable non-woven towels and using the disposable non-woven towel could save RMB 122962.50 annually. Conclusion: Compared with the plain cotton towel, the non-woven shares the advantages of none flocculation, longer storage time and better antibacterial effect as well as the material, cleaning and labor costs-saving. The cost of the disposable non-woven treatment towel is lower than that of the reusable plain cotton towel. Therefore, it is recommended to use the disposable non-woven treatment towel.

Non-wovens Satisfy the Textile Industry at the Beginning of 2006

The economic performance of China’s non-woven industry in the first two months of

Non-woven Industry Weaves a Beautiful Pattern

As one of the three backbone con- sumptions (apparel, home-textile, tech- textile or industrial applications), non- woven textile industry performed well in 2005, but problems still remain. An official from the State Development and Reform Commission - China’s top planner, mapped out economic blue- prints for this fast-growing sector in 2006.

多色无纺布包装材料在手术器械灭菌管理中的应用效果

目的:分析多色无纺布包装材料在手术器械灭菌管理对手术周转效率、手术器械准备情况及外科医护人员与患者满意度等影响。方法:选取2016年3月至2021年12月首都医科大学附属北京友谊医院消毒供应中心的31589件手术器械,根据管理方法不同,将2016年3月至2019年1月的71007例手术患者及患者使用的16224件手术器械纳入对照组,采用传统的纱棉布包包装手术器械管理方法。将2019年2月至2021年12月的62548例手术患者及患者使用的15365件手术器械纳入观察组,采用多色无纺布包装材料手术器械管理方法,比较两组手术周转效率、手术器械准备情况及患者与外科医护人员的使用管理满意度。结果:观察组患者手术的入室时间、入室-切皮时间、接台手术入室-切皮时间及手术延误率均低于对照组,差异有统计学意义(t=52.681、37.167、72.524,χ^(2)=9.605,P<0.05)。与对照组比较,观察组外出送物品次数、装配错误和器械丢失明显降低,器械完好件数明显提高,差异有统计学意义(χ^(2)=107.345、11.782、8.727、66.223,P<0.05);观察组患者及医护人员器械使用管理的满意度显著高于对照组,差异有统计学意义(t=100.723、6.756,P<0.05)。结论:手术器械运用多色无纺布包装材料有助于提高手术周转率,通过降低外出送物品次数、装配错误及器械丢失提高消毒供应中心工作效率,改善外科医护人员与患者对手术器械多色无纺布包装材料的满意度。

“无机粒子-无纺布”协同改性碳纤维复合材料及其增韧机理

针对碳纤维复合材料层间性能较差、易发生分层损伤的问题,提出一种采用SiC粒子和热塑性共聚酰胺(PA)无纺布对碳纤维/环氧树脂基复合材料(CFRP)进行增韧改性的技术,在层间构筑一种“无机颗粒/热塑性纤维/树脂基体”多组分多尺度增韧相体系,对比分析改性前后复合材料的Ⅰ型、Ⅱ型层间断裂韧性和耐热性,借助扫描电子显微镜(SEM)和动态热机械分析仪揭示其增韧和耐热性机制。结果表明,与未改性的CFRP材料相比,当SiC填充量(质量分数)为1%、PA无纺布面密度为25 g/m2时,改性CFRP材料Ⅰ型层间断裂韧性(GⅠC)和Ⅱ型层间断裂韧性(GⅡC)分别提高了52.7%和222.6%。无机粒子的阻滞效应、纤维的桥连效应和基体树脂的塑性变形是其主要增韧机制。

GN-g-MAH/PPy多功能PET非织造布的制备及应用

为提高聚酯(PET)非织造布的性能,将导电材料通过表面改性引入PET非织造布,采用单宁酸(TA)作为桥联剂,功能化石墨烯(GN-g-MAH)和聚吡咯(PPy)作为导电功能层,制备得到多功能PET非织造布,并使用SEM、XRD、TG等测试了PET/GN-g-MAH/PPy的微观结构和热稳定性。结果表明:通过循环自组装法及低温化学聚合法成功制备了PET/GN-g-MAH/PPy非织造布,表现出良好的导电性,表面电阻率低至3.11×10^(-2)Ω·m,表面由疏水转变为亲水。基于此,非织造布也表现出优异的电热性能,对其施加3 V驱动电压时,可在20s内产生约40℃的饱和温度。此外,还具有良好的光热转换性能,当光照强度为300 mW/cm^(2)时,照射20 s后,表面温度可稳定到105.8℃,非织造布还表现出优异的光热抗菌性,当大肠杆菌的菌液浓度为1.6×10^(8)CFU/mL时,使用氙灯模拟太阳光源照射后,抗菌率达到99.6%。

空气净化技术研究(1):纤维过滤

纤维过滤是目前使用最广泛的空气净化技术,主要滤材有无纺布、玻璃纤维、驻极体静电纤维、聚四氟乙烯(PTFE)膜和纳米纤维。本文比较了国内外主要空气过滤器标准中的效率规格,介绍了这5种纤维过滤器的特点,分析了国内外文献报道的这些过滤器的主要性能和优缺点。对3种空气过滤器,即用驻极体静电纤维、PTFE纤维和静电纺丝纳米纤维制造的空气过滤器进行了测试,其中静电纺丝纳米纤维和PTFE纤维空气过滤器虽然仍存在不足,但是已实现了高效低阻的目标。面对全球肆虐不断的各种流行性疾病,空气过滤器不但需要实现高效率、低阻力,更应具备杀灭细菌和灭活病毒的功能,新的、性能更优的纤维过滤材料和空气过滤器有待开发和应用。

纯棉无纺布低温近中性练漂体系构建及其工艺优化

纯棉无纺布练漂在高温强碱中进行,能耗高、排污大、纤维损伤严重。针对该问题,试验构建了三种低温近中性练漂体系,通过对比三者练漂无纺布的颜色特征值、亲水性能和机械性能,选出最优体系;采用XRD、FT-IR、SEM分析体系对棉纤维微观结构与形貌的影响;通过中心复合设计(CCD)优化该体系漂白工艺,并寻求影响织物白度(WI)的关键因素。研究表明:四乙酰乙二胺/过氧化氢(TAED/H2O2)体系练漂织物WI最高,亲水性优良,强力损伤最小(<20%);练漂体系对棉纤维晶型结构与官能团无影响,能有效去除纤维表面杂质,保护纤维不受损伤。CCD结果显示,温度对WI影响最显著,其次是H2O2浓度与NaHCO3浓度;在最优条件下,得到的理论最优WI为90.38,比原布WI高39.32%。

超吸水织物的制备及性能研究

以丙烯酸为单体,过硫酸钾、亚硫酸氢钠为氧化还原引发剂,与聚乙烯醇共混,采用溶液聚合法制备了丙烯酸高聚物溶液,浸轧丙纶热熔无纺布织物,经烘干得到超吸水织物,通过傅里叶变换红外光谱仪、场发射扫描电子显微镜、同步热分析仪对超吸水织物的结构、形貌和热性能进行分析,考察了聚合反应水浴温度、丙烯酸中和度、聚乙烯醇添加量、带液率对吸水倍率的影响,并对吸水机理进行探讨。结果表明:在聚合反应水浴温度为75℃,丙烯酸中和度75%,聚乙烯醇添加量(对单体)为5%(质量分数),带液率为500%,烘干温度为120℃条件下,制备的超吸水织物吸蒸馏水倍率为109.82g/g。

CNT/rGO复合三维非织造材料基柔性压力传感器的制备及性能

针对织物基柔性压力传感器灵敏度低、响应范围窄和制备工艺复杂的问题,以自制的三维热熔纤维非织造材料为基材,采用超声波辅助浸渍碳纳米管(CNT)和还原氧化石墨烯(rGO)协同修饰纤维表面,构建出具备高灵敏度和耐久性的三维热熔非织造材料基压力传感器,并对该传感器的结构形貌、传感性能和健康监测性能等进行测试。结果表明,该传感器具有高灵敏度(在0~9.28 kPa监测压强范围内,灵敏度为2.33×10^(-2) kPa^(-1))、快速响应/回复时间(70 ms/90 ms)、宽感测范围(0~227 kPa)和优异的循环耐久性(约16000次循环)。该传感器可以用于人体健康监测、运动监测和语音监测等领域。