Frictional and Tensile Properties of Conducting Polymer Coated Wool and Alpaca Fibers

Wang Lijing,Lin Tong,Wang Xungai,Kaynak Akif The Korean Fiber Society 2005 Fibers and polymers Vol.6 No.3

Wool and alpaca fibers were coated with polypyrrole by vapor-phase polymerisation method. The changes in frictional and tensile properties of the single fibers upon coating with the conductive polymer are presented. Coating a thin layer of polypyrrole on the alpaca and wool fibers results in a significant reduction in the fiber coefficient of friction, as the conducting polymer layer smooths the protruding edges of the fiber scales. It also reduces the directional friction effect of the fibers. Depending on the type of fiber, the coating may slightly enhance the tensile properties of the coated fibers.

Compressive and Flexural Properties of Hemp Fiber Reinforced Concrete

Li, Zhijian,Wang, Lijing,Wang, Xungai The Korean Fiber Society 2004 Fibers and polymers Vol.5 No.3

The compressive and flexural properties of hemp fiber reinforced concretes (FRC) were examined in this paper. Natural hemp fiber was mixed using dry and wet mixing methods to fabricate the FRC. Mechanical properties of the FRC were investigated. The main factors affecting compressive and flexural properties of the FRC materials were evaluated with an orthogonal test design. Fiber content by weight has the largest effect. The method for casting hemp FRC has been optimised. Under the optimum conditions, compressive strength increased by 4 %, flexural strength increased by 9 %, flexural toughness increased by 144 %, and flexural toughness index increased by 214 %.

Effects of Bleaching and Dyeing on the Quality of Alpaca Tops and Yarns

Liu, Xin,Wang, Lijing,Wang, Xungai The Korean Fiber Society 2004 Fibers and polymers Vol.5 No.2

This paper reports the effects of bleaching of alpaca tops and dyeing of bleached alpaca tops/yarns on the quality of tops and yarns. A dark brown alpaca top was bleached with hydrogen peroxide. Two bleaching methods were tried for effectiveness of color removal. A portion of each bleached top was dyed after bleaching. Color parameters were examined for unbleached, bleached and bleached/dyed tops, these tops were then converted into yarns of different twist levels and counts using a worsted spinning system. Some of the bleached yarn from each bleaching method was dyed in a package dye vat to compare the difference of top dyeing versus yarn package dyeing on yarn quality. Fiber diameter, yarn strength, yarn evenness, yarn hairiness and fiber degradation were tested to examine the effects of bleaching and dyeing on these properties at top and yarn stages. A processing route for bleaching and dyeing alpaca fiber was recommended.

STRONG CONVERGENCE OF HYBRID METHOD FOR ASYMPTOTICALLY NONEXPANSIVE MAPPINGS AND SEMIGROUPS

Liu, Li,Wang, Lijing,Su, Yongfu The Korean Society for Computational and Applied M 2011 Journal of applied mathematics & informatics Vol.29 No.3

In this paper, some strong convergence theorems are obtained for hybrid method for modified Ishikawa iteration process of asymptotically nonexpansive mappings and asymptotically nonexpansive semigroups in Hilbert spaces. The results presented in this article generalize and improve results of Tae-Hwa Kim and Hong-Kun Xu and others. The convergence rate of the iteration process presented in this article is faster than hybrid method of Tae-Hwa Kim and Hong-Kun Xu and others.

Diameter Variations of Irregular Fibers under Different Tensions

Deng, Chuanming,Wang, Lijing,Wang, Xungai The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.6

The cross-section area of animal fibers varies along the fiber length, and this geometrical irregularity has a major impact on the mechanical properties of those fibers. In practice fibers are often subjected to tensile stresses during processing and application, which may change fiber cross-section area. It is thus necessary to examine geometrical irregularity of fibers under tension. In this study, scoured animal fibers were subjected to different tensile loading using a Single Fiber Analyzer (SIFAN) instrument. The 3D images of the fiber specimens were first constructed, and then along-fiber diameter irregularities of the specimens were analyzed for different levels of tensile loading. The changes in effective fineness of the fiber specimens were also discussed. The results indicate that for the wool fibers examined, there is considerable discrepancy in the fiber diameter results obtained from the commonly used single scan along fiber length and that from multiple scans at different rotational angles, and that the diameter variation along fiber length increases as fiber tension increases. The results also show that when diameter reduction treatments are applied to wool by stretching, the reduced average fiber diameter is associated with an increase in both within-fiber and between-fiber diameter variations. So in terms of effective fineness, the change is much smaller than the difference between the average diameters of the parent and treated wool. These results have significant implications for improving the accuracy of fiber diameter measurement and evaluation.

First principles studies on the elastic, thermodynamic properties and electronic structure of Ti15−xMoxSn compounds

Chunmei Chen,Wei He,Lijing Ding,Xiaohui Song,Jinhui Huang,Tao Wang,Guoren Huang 한국물리학회 2018 Current Applied Physics Vol.18 No.3

The structural, elastic, thermodynamic and electronic properties of the Ti15−xMoxSn compounds were systematically investigated by means of first-principles calculations based on the density functional theory (DFT). The calculated results demonstrate the Ti15−xMoxSn compounds still remain the stable β phase structure. The calculation of cohesive energy shows that the structural stability of the Ti15−xMoxSn compounds increases apparently with the increase of Mo content. According to Hooke's law, the single crystal elastic constants were obtained and show that all the calculated compounds keep mechanical stability. Then the bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio ν of polycrystalline aggregates were calculated at zero pressure. The calculated results show that among these Ti15−xMoxSn compounds, Ti4Mo11Sn exhibits the largest stiffness while Ti12Mo3Sn shows the greatest ductility. The compounds Ti12Mo3Sn and Ti11Mo4Sn with the two lowest elastic Young's modulus of 61.01 GPa and 65.59 GPa are expected to be promising metallic biomaterials for implant applications. Besides, the Debye temperature ΘD and the electronic density of states (DOS) are also investigated and discussed.

An Experimental Investigation of Yarn Tension in Simulated Ring Spinning

Tang Zheng-Xue,Wang Xungai,Fraser W. Barrie,Wang Lijing The Korean Fiber Society 2004 Fibers and polymers Vol.5 No.4

Yarn tension is a key factor that affects the efficiency of a ring spinning system. In this paper, a specially constructed rig, which can rotate a yam at a high speed without inserting any real twist into the yarn, was used to simulate a ring spinning process. Yarn tension was measured at the guide-eye during the simulated spinning of different yarns at various balloon heights and with varying yarn length in the balloon. The effect of balloon shape, yarn hairiness and thickness, and yam rotating speed, on the measured yarn tension, was examined. The results indicate that the collapse of balloon shape from single loop to double loop, or from double loop to triple etc, lead to sudden reduction in yarn tension. Under otherwise identical conditions, a longer length of yarn in the balloon gives a lower yarn tension at the guide-eye. In addition, thicker yarns and/or more hairy yarns generate a higher tension in the yarn, due to the increased air drag acting on the thicker or more hairy yarns.

RFID in textile and clothing manufacturing: technology and challenges

Rajkishore Nayak,Amanpreet Singh,Rajiv Padhye,Lijing Wang 한국의류학회 2015 Fashion and Textiles Vol.2 No.1

In the field of textile and clothing, radio frequency identification (RFID), which is one of the most promising technological innovations, is used in manufacturing, inventory control, warehousing, distribution, logistics, automatic object tracking and supply chain management. Various retailers and manufacturers (of clothing as well as consumer goods) such as CVS, Tesco, Prada, Benetten, Wal-mart and Procter & Gamble, are now implementing the technology and exploring the impact of the technology on their business. RFID technologies may improve the potential benefits of supply chain management through reduction of inventory losses, increase of the efficiency and speed of processes and improvement of information accuracy. The basic of success lies in understanding the technology and other features to minimize the potential problems. Although the technology existed for several years, the technological challenges and cost issues are the major hurdles for the widespread use of RFID. In this paper, the authors have addressed the technology of RFID and various applications related to inventory management, production control, retail management, brand segregation etc. in textile and clothing industry. In addition, the disadvantages, challenges and future directions of RFID technology have also been highlighted.

Impact Resistance and Comfort Properties of Textile Structures for Sportswear

Rajkishore Nayak,Sinnappoo Kanessalingam,Arun Vijayan,Lijing Wang,Rajive Padhye,Lyndon Arnold 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

Protective padding is commonly used in many sporting activities to prevent impact related injuries. In rugby,shoulder pads absorb and disperse the force and energy of an impact with a playing surface or another player. Although themajority of the commercial shoulder pads currently available can reduce the impact force during a front-on tackle, theyprovide limited amount of thermal comfort to the wearer. In this research, flexible textile structures were designed andinvestigated for their potential to effectively dissipate the force of impact over a wider area, thus reducing the risk of injury. The impact resistance of these textile structures placed over a body simulant was compared against commercial foam padsusing a ‘drop test’ method. The results indicated that all the flexible textile structures reduced the impact force. Although theirprotection level was not as high as the commercial foam, the textile structures showed a higher level of thermal comfort asmeasured by air permeability, thermal resistance and water vapor resistance. The results were analyzed using onewayANOVA followed by post-hoc analysis using IBM SPSS software. The Post-hoc analysis showed a significant differenceamong the test results of various fabrics for impact absorption, air permeability, thermal resistance and water vaporresistance, which are also discussed in this paper.

3D Bioprinted GelMA/PEGDA Hybrid Scaffold for Establishing an In Vitro Model of Melanoma

( Jiahui Duan ),( Yanyan Cao ),( Zhizhong Shen ),( Yongqiang Cheng ),( Zhuwei Ma ),( Lijing Wang ),( Yating Zhang ),( Yuchuan An ),( Shengbo Sang ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

Due to the high incidence of malignant melanoma, the establishment of in vitro models that recapitulate the tumor microenvironment is of great biological and clinical importance for tumor treatment and drug research. In this study, 3D printing technology was used to prepare GelMA/PEGDA composite scaffolds that mimic the microenvironment of human malignant melanoma cell (A375) growth and construct in vitro melanoma micro-models. The GelMA/PEGDA hybrid scaffold was tested by the mechanical property, cell live/dead assay, cell proliferation assay, cytoskeleton staining and drug loading assay. The growth of tumor cells in two- and three-dimensional culture systems and the anti-cancer effect of luteolin were evaluated using the live/dead staining method and the Cell Counting Kit-8 (CCK-8) method. The results showed a high aggregation of tumor cells on the 3D scaffold, which was suitable for long-term culture. Cytoskeleton staining and immunofluorescent protein staining were used to evaluate the degree of differentiation of tumor cells under 2D and 3D culture systems. The results indicated that 3D bioprinted scaffolds were more suitable for tumor cell expansion and differentiation, and the tumor cells were more aggressive. In addition, luteolin was time- and dose-dependent on tumor cells, and tumor cells in the 3D culture system were more resistant to the drug.