非织造布气流成网横向重量不匀率的测试与分析

本文作者为提高非织造布SW-63型气流成网机的成网质量,测试了在不同进风方式下风速与纤维网横向重量不匀率的关系;在此基础上研讨了影响气流成网横向不匀的因素;并认为提高纤维开松程度、梳理程度,控制补风方式是降低纤维网横向不匀率的有效途径.     

气流成网过程中几个问题的理论分析

在气流成网机典型化的风道结构基础上,对纤维从锡林上脱离的影响因素、纤维网的形成结构,气流分布及流量进行了理论分析,并推导出了上述问题的理论模型。     

木浆纤维水刺复合不同加固结构纤网时的流失现象

木浆纤维经气流成网后,分别与PP/PE(聚丙烯/聚乙烯)纺黏热轧非织造布、PP/PE短纤热轧非织造布、PP/PE短纤热风非织造布和涤纶水刺非织造布纤网叠合形成试样,通过水刺复合,观察水针冲击过程中不同加固纤网结构条件下木浆纤维的流失现象,研究木浆纤维的流失过程和机理,并分析非织造布纤网结构对木浆纤维流失的影响.试验表明:木浆纤维与非织造布纤网中的纤维缠结以摩擦作用为主,当水针冲击力大于纤维之间的摩擦力,纤维互相分离,木浆纤维易脱离纤网而流失;在相同压力的水针冲击条件下,木浆纤维与PP/PE纺黏热轧非织造布、PP/PE短纤热轧非织造布及PP/PE短纤热风非织造布纤网复合时其流失严重,流失率均高于8%,而涤纶水刺非织造布纤网适于与木浆纤维的缠结,木浆纤维的流失率低,仅为2.95%.     

从粉末粘结非织造布中抽拔纤维的研究

研究了单根纤维从粉末粘结非织造布中的抽拔行为．大批抽拔时纤维的抽拔力与根数的频数之间基本符合伽玛分布规律．平均抽拔力与粉末含量的关系趋势基本呈“Ｓ型”曲线．计算了粘结纤维网中纤维的强度利用率，发现提高粘结纤维网的强力还大有潜力．     

精梳落棉非织造吸油材料的制备及性能

以精梳落棉纤维为吸油主体,三维卷曲涤纶为骨架构造,ES纤维作为黏结成分,分别通过梳理成网和气流成网方式制备不同结构的纤维网,并进行热风黏合加固,表面喷洒硅油,制备精梳落棉非织造吸油材料.通过正交试验的方法探索原料混比、硅油用量对吸油材料吸油性能的影响.结果显示,成网方式和纤维配比对材料吸油性能有显著影响,在气流成网方式下,当棉/涤纶混比为80/20、ES纤维含量为10%、硅油含量为15%时,材料的吸油倍率、保油率和吸水率达到最优值.     

秸秆纤维气流成网过程中工艺参数的影响

采用气流成网技术将稻草纤维制成纤维网，在成形过程中对气流和喂给量两个工艺参数进行了试验，研究和评价了这两个参数对成形过程中稻草纤维脱落以及最终纤维网的质量均匀度偏差的影响。     

射流喷网非织造布工艺技术的研究

本文研究了最新的非织造布加固技术——射流喷网工艺,其基本原理与针刺加固相似,采用高压水针替代机械针刺,纤网在水流直接和反弹的双重作用下,纤维缠结加固。实验表明:预水刺时,各注射器的水压能量须逐个提高,纤维的缠结效果好,并提出了原料、速度、压力、温度等关健技术参数。纤网定量降低,注射器数量增加,涤纶射流非织造布机械性能比棉纤维的好,纤维种类和强力对非织造布性能有较大的影响。随着纤网定量的增加,断裂强度,撕破强度和顶破强度增加。漂白棉射流非织造布手感比涤纶纤维差,射流法非织造布的撕裂强度曲线呈锯齿形。     

空气净化用角蛋白非织造材料的制备及性能

为实现空气过滤材料既能过滤微细颗粒物又能去除有害气体的多功能化，采用非织造工艺和冷冻干燥技术相结合的方式，制备双组分热熔黏结(ES)纤维和角蛋白再生纳米纤维双峰纤维嵌合结构的多功能空气过滤非织造材料。以聚丙烯/聚乙烯(PP/PE)双组分纤维为原料，经过杂乱凝聚成网技术制备蓬松纤维网，再分别经针刺、热风加固技术加工获得非织造材料；采用浸渍和冷冻干燥技术使角蛋白纳米纤维均匀生长于非织造材料内部，制成具有双峰纤维嵌合结构的非织造过滤材料。结果表明，经角蛋白纳米纤维嵌合的非织造材料的过滤效率由27.9%增加至93.9%,甲醛去除效率达54.2%。     

粘合剂粒径对非织造布性能的影响

探讨了粘合剂粒径对非织造布力学性能的影响。实验表明,随着粒径变细,非织造布的拉伸强度和弯曲模量呈非线性增加。分析认为由细旦纤维制成的非织造布可具有较高的拉伸强度和较低的抗弯模量,这些概念也适用于热熔纤维粘合和热轧非织造布。     

分裂型纤维水刺非织造布的双向拉伸开纤方法

采用双向拉伸的方法对分裂型纤维水刺非织造布进行处理,研究该拉伸方法对分裂型纤维开纤效果的影响.结果表明:双向拉伸法可以有效提高分裂型纤维的开纤率;拉伸负荷越大、拉伸速度越快,则纤维平均直径越小,开纤率越高;经小负荷双向拉伸处理后,非织造布材料强力有所降低,但当拉伸负荷较大时,处理后的非织造布强力明显提高.双向拉伸开纤方法适用于交叉铺网的水刺非织造布,与化学开纤法相比,不但纤维损伤小,而且工艺简单、无环境污染.     

Adhesion of PBO Fiber in Epoxy Composites

The high mechanical and thermal performance of poly p-phenylene- 2, 6-benzobisoxazole ( PBO ) fiber provides great potential applications as reinforcement fibers for composites. A composite of PBO fiber and epoxy resin has excellent electrical insulation properties, therefore, it is considered to be the best choice for the reinforcement in high magnetic field coils for pulsed magnetic fields up to 100 T.However, poor adhesion between PBO fiber and matrix is found because of the chemically inactive and/or relatively smooth surface of the reinforcement fiber preventing efficient chemical bonding in the interface, which is a challenging issue to improve mechanical properties. Here, we report the surface modification of PBO fibers by ultraviolet (UV)irradiation, O2 and NH3 plasma, as well as acidic treatments. The interfacial adhesion strength values of all the treatments show the similar level as determined for aramid fibers by pull-out tests, a significant impact on fibermatrix-adhesion was not achieved. The surface free energy and roughness are increased for both sized and extracted fibers after plasma treatments together with maleic anhydride grafting. The sized fiber shows marginal improvement in adhesion strength and no change in fiber tensile strength because of the barrier effect of the finish.For the extracted fiber, different surface treatments either show no apparent effect or cause reduction in adhesion strength. Atomic force microscopy (AFM) topography analysis of the fracture surfaces proved adhesive failure at the fiber surface. The fiber surface roughness is increased and more surface flaws are induced, which could result in coarse interface structures when the treated fiber surface has no adequate wetting and functional groups. The adhesion failure is further confirmed by similar adhesion strength and compression shear strength values when the fiber was embedded in various epoxy resins with different temperature behavior. The tensile strength of fiber is sensitive to surface treatment conditions as revealed by a bimodal Weibull statistical distribution analysis. Considerable strength reduction occurred, particularly for cases of acidic and plasma treatments, while UV irradiation shows the better ability to retain fiber strength.     

超高相对分子质量聚乙烯纤维的表面粘结性能研究

在萃取阶段用表面改性剂溶液对超高相对分子质量聚乙烯（UHMWPE）冻胶纤维进行表面处理，然后经过多级热拉伸制得改性纤维。对萃取液进行了紫外吸光度分析，并对改性前后纤维的表面化学结构、力学性能和表面粘结性能进行了比较。结果表明；经表面处理的纤维表面引入许多极性基团，纤维粘结强度随拉伸倍数增加而提高，纤维粘结性能得到较大改善；表面处理对纤维的力学性能影响不大。其中EVA的改性效果最为明显，3级拉伸后纤维的粘结强度提高了100％．     

Influence of Fabric Geometrical Structure on Bonding of the Fabric Reinforced Cement Composites

Influence of fabric geometrical parameters,including the number of filling yams per 10 cm, yarntwist and fiber type, on bonding of the fabric reinforcedcement composites is studied by fabric pull-out test andSEM microstructure analysis. The results show that thebonding strength increase with the increase of the numberof filling yams per 10 cm in the range of this study. Butthe influence of fabric count on the interfacial bonding isdual and there is a critical value. The twist of yarns hasa little effect on the bending strength and interfacialbonding behaves of nylon fabric reinforced cementcomposites. There is an optimum twist range. Withinthis range, the bonding strength increase slowly with theincrease of yarn twist. Beyond this range, it is versus.The bonding strength is strongly affected by the fabriccharacter. The bonding between the nylon fiber fabricand cement is good; that of between glass fiber fabric andcement is moderate and that of between the carbon fiberfabric and cement is poor.     

The Surface Properties and Tensile Strength of HSPE Fiber Treated by Controlling Oxidation in Chromic Acid

This work reported on the surface modification of high strength polyethylene(HSPE)fiber by chemical etching in chromic acid.The surface chemistry,the functional group contents, the wetting ability, the surface morphology and the tensile strength of modified fibers were investigated. The results show that, the surface roughness,surface wet properties and active functional group can be introduced on the HSPE fiber surface by this method,which will improve the interface adhesion in the composites, and the decrease of the tensile strength of modified fibers can be controlled.     

集成光子器件封装形式对器件性能的影响

集成光子器件封装过程中,波导芯片与阵列光纤对准耦合完成之后,需用紫外光固化胶进行固接,从而实现光路的互连。针对1×4通道平面波导芯片与阵列光纤的固接,以粘接区域为研究对象,通过-40~80℃的温度循环,采用有限元法分析各种固接形式的应力集中点、应力双折射、耦合损耗的变化规律及其因素;最后通过比较各种固接形式的仿真结果,得出结论,从而指导实验。结果表明:在-40~80℃范围内,温度对粘接面的应力双折射和耦合损耗的影响很小;双盖板固接形式对器件性能的影响最小,斜8°固接形式的效果最差。     

竹浆纤维再回收利用及纸张强度改善

 研究了竹浆纤维的循环再利用及超声波处理对竹浆纤维和纸张特性的影响;评价了竹浆纸张的密度、抗张强度等特性,探讨了单纤维强度和纸张纤维间结合力的关系。结果表明,竹浆纸张的密度和抗张强度随着循环再利用次数的增加而降低,超声波处理纸浆纤维提高了纸张的抗张强度。Page理论表明,纸张抗张强度的提高主要是由于超声波处理增强了纸张内部的纤维间结合力。光学显微镜结果显示,超声波处理通过切断纤维、润胀纤维、细纤维化纤维的作用,有效改善了纸张的强度。研究表明,纸张的循环再利用会降低竹浆的保水值,而利用超声波处理可以有效提高纸浆的保水性能,改善纸张的抗张强度。     

酶改善二次纤维结合性能的研究

以二次纤维为研究对象，分别用半纤维素酶和纤维素酶对其进行处理，以改善二次纤维的结合性能，寻找酶处理的最佳条件．并用扫描电镜(SEM)观察二次纤维处理前后表面形态的变化．研究结果表明，提高纸页强度主要靠改善二次纤维的结合性能．半纤维素酶处理时半纤维素与纤维表面的木聚糖反应，打开半纤维素之间氢键的联结，使纤维表面细纤维化并增加润胀，改善了其结合性能．纤维素酶处理时其C1酶破坏纤维素链的结晶结构，使纤维易于润胀，因此增强了二次纤维的结合性能．     

高石粉含量下C80混凝土力学性能数值模拟研究

为研究石粉含量和纤维掺量对C80混凝土基本力学性能（包括立方体抗压强度、轴心抗压强度、抗折强度、劈裂抗拉强度和弹性模量）的影响,本文结合Digimat和Abaqus建立2D随机骨料模型、3D纤维混凝土细观模型。将不同石粉含量、纤维掺量下混凝土的数值模拟与同等条件下基本力学试验结果进行对比分析：2D随机骨料模型中过高（石粉含量大于5%时称为高石粉含量）的石粉含量会降低混凝土的整体力学性能,石粉含量越低模拟值与试验值越接近,当石粉含量为5%时混凝土的整体力学性能达到最佳。3D纤维混凝土细观模型中不同纤维类型对高石粉含量混凝土的强度有不同影响,与玄武岩纤维相比,铜镀纤维的掺入对高石粉含量下混凝土力学性能的增幅更明显。铜镀纤维体积分数为4%和6%时均能提高混凝土力学性能,当体积分数为6%时,混凝土数值模拟与试验结果误差小于7.1%且力学性能达到最优;玄武岩纤维混凝土的抗压性能随纤维体积率的增加而降低,当纤维体积率为1 kg/m3时数值模拟结果与试验结果误差范围在0.4%-8.7%,但对混凝土整体力学性能的提升较小。     

Enhancement of Adhesive Strength of Ultrahigh Molecular Weight Polyethylene Fibers Prepared by Polar Polymer Implantation

A new technique was proposed to enhance the adhesive strength of ultrahigh molecular weight polyethylene （UHMWPE） fibers. Polar polymer was implanted into UHMWE gel fibers during extracting process and can then be trapped on the surface of the fibers after subsequent ultra-drawing. The physical and chemical changes in the fiber structure were examined with scanning electron microscopy （SEM） and Fourier transform infrared （FTIR） spectroscopy. The mechanical and interfacial adhesion properties of UHMWPE fibers were investigated with tensile testing. The results showed that there were polar groups on the smface of pretreated UHMWPE fiber. The interracial shear strength of UHMWPE fibers with epoxy resin was greatly improved without sacrificing the excellent mechanical p~perties of fibers. After pretreated with ethylene/vinyl acetate copolymer （EVA）, the shear strength of the interface between fiber and epoxy resin increased from 1.06 to 2.49 MPa, while the integrated mechanical properties d the pretreated UHMWPE fibers were still optimal.     

纳米二氧化硅修饰玻纤表面对玻纤增强聚丙烯复合材料性能的影响

基于纳米颗粒比表面积高的特性，将超声震荡分散后的纳米SiO₂通过化学接枝方法修饰玻璃纤维表面制备玻璃纤维/聚丙烯热塑性复合材料。通过扫描电子显微镜（SEM）表征纳米SiO₂在玻纤表面的分布状态及其与纤维树脂的结合情况，结果表明纳米颗粒在纤维表面分布状况良好，纤维与树脂能较为紧密地结合。通过动、静态力学测试表征复合材料的界面结合情况及整体力学性能，结果表明复合材料在动态热机械分析（DMA）测试下具备良好的综合界面性能；与空白组对比，复合材料的层间剪切强度最高提升约86%，拉伸强度最高提升约300%，弯曲强度最高提升约94%。