MANUFACTURING OF TUBULAR LENO FABRICS BY MODIFIED STANDARD SAMPLING LOOM

Leno fabric pattern was first developed at the beginning of the 1900’s. Leno weaving structures, which are net-like porous, also called gauze, cross or doup weave. There are several types of leno fabrics which included plain and fancy lenos. Although, plain leno-weave structures is used mainly to make selvedge in the industrial weaving machineries, the fancy leno-weave fabrics are used for home, industrial, agricultural, medical and geo textiles and civil engineering applications, as well. Leno structures is woven by special manufactured leno weaving to exemplify circular leno looms. In order to produce leno fabrics are used leno heddle types. Essentially, lenos fabric is formed that one warp yarn is raised and passed over from one side of adjacent warp yarn. When the two adjacent warp yarns is twisted, weft yarn is inserted them, as well. Because of porous and entangled structures, they are lighter but stronger than plain structures. In this study, Firstly, we have woven tube-like leno structure by modifying Automatic Sampling Loom. Secondly, it was woven double layered tubular leno fabrics from different types of yarns by modifying standard automatic sampling loom and measured the mechanical properties of resultant. In the last part of study, to investigate surface characteristic feature more closely, we used a stereo microscope

Fabrication of Woven Honeycomb Structures for Advanced Composites

A honeycomb woven fabric was designed and produced on a sampling loom. After weaving cells in the fabric were opened by polytetrafluoroethylene (PTFE) sticks and an epoxy resin was applied to fabric. For comparison half of the fabric sample was impregnated with resin without opening the cells. Resulting fabric samples were subjected to low-velocity impact test by using drop weight impact testing machine, CEAST Fractovis Plus – 7526.000. To evaluate the impact behaviour of the samples the contact force, contact time, deflection, and absorbed energy values were recorded by data acquisition system (DAS). The energy absorbed by honeycomb structure was around 7 Joule. The energy absorbed by flat sample, on the other hand, was too low and out of the detection range of the testing equipment

Polyamide 6/chitosan nanofiber coated HEPA filter for bioaerosol control

WOS: 000422819200004The aim of this study was to electrospun uniform nanofibers with antibacterial properties, to combine them with a high-efficiency particulate air (HEPA) filter material and to determine the filter performance of this composite filter. To achieve these objectives, polyamide 6 (PA 6)/chitosan (CS) blend nanofibers were produced and their antibacterial activity was analyzed. Then PA 6/CS nanofibers were coated on a commercial HEPA filter material and the filter performance of this composite filter was tested. Antibacterial activity analysis indicated that PA 6/CS nanofibers had very good antibacterial activity against both Staphylococcus aureus and Escherichia coli. Nanofiber coating improved the filter efficiency of the HEPA filter. However, it also increased pressure drop. The filter efficiency increased with decreasing nanofiber size in nanofiber coated HEPA filter. Pressure drop did not follow the same trend. First, it decreased with decreasing fiber diameter, but a further decrease in fiber diameter caused an increase in pressure drop. In conclusion, nanofiber size has a great effect on pressure drop and to get high filter efficiency without a substantial increase in pressure drop a careful selection of nanofiber size is essential

Effects of some process parameters on the structure and properties of vortex spun yarn

WOS: 000239031000007The effects of a number of process parameters, including the nozzle angle, nozzle pressure, spindle diameter, yarn delivery speed, and distance between the front roller and the spindle, on the structure and properties of vortex spun yarns were investigated. A modified version of the tracer fiber technique (J. Text. Inst., 43, T60-T66, 1952) combined with the Image Analysis Application Version 3.0 (B.A.R.N. Engineering) was utilized to explore yarn structure. The migration behavior of fibers was characterized using the migration parameters introduced by Hearle et al. (Text. Res. J., 35, 329-334,788-795, 1965). The results showed that the short front roller to the spindle distance caused better evenness, low imperfections, and less hairiness. High nozzle angle, high nozzle pressure, low yarn delivery speed and small spindle diameter reduced hairiness as well. High nozzle angle, high nozzle pressure and low speed also led to higher fiber migration. Surprisingly nozzle angle, nozzle pressure or delivery speed did not have any significant effects on yarn tensile properties. This is believed to be caused by the relatively small differences between the levels of these parameters used in the trials. The present study provides a window into the vortex spinning technology, but further research needs to be conducted to establish a "process-structure-property model" for vortex yarns

Preparation of PCM microcapsules by complex coacervation of silk fibroin and chitosan

WOS: 000271723200009Phase change material microcapsules were prepared by complex coacervation of silk fibroin (SF) and chitosan (CHI). n-Eicosane was used as the core material. The effects of SF/CHI ratio, and percentage of cross-linking agent and n-Eicosane content on the properties of microcapsules were studied. The size distribution and the surface morphology of microcapsules were characterized by optical and scanning electron microscopy. The encapsulation of core material was determined by energy dispersive spectrometer analysis. The results indicated that SF/CHI microcapsules were prepared successfully. Microcapsules had smooth outer surface when the ratio of SF to CHI was close to 5. On the other hand, at high SF/CHI ratios (a parts per thousand yen14), microcapsules showed a two-layer structure, an inner compact layer, and an outer, more porous, sponge-like layer. The highest microencapsulation efficiency was obtained at a SF/CHI ratio of 20 in the presence of 0.9% cross-linking agent and of 1.5% n-Eicosane content.Ege University Research FoundationEge University [08-MUH-042]The authors greatly appreciate the financial support provided by Ege University Research Foundation (project number 08-MUH-042)

A Functional Fabric for Pressure Ulcer Prevention

WOS: 000270763000001Pressure ulcers, also known as bed sores, pressure sores and decubitus ulcers, are localized areas of tissue damage that develop due to pressure usually over a bony prominence. They are associated with adverse health outcomes and high treatment costs. This study focused on developing a functional fabric for pressure ulcer prevention. For this purpose, face-to-face velour weaving technique was utilized to produce a spacer fabric from the different combinations of engineered polyester, polypropylene, cotton and viscose fibers. Thermal conductivity, thermal resistance, thermal absorptivity, water vapor permeability, wicking ability, compressibility and fabric hand properties of the resultant 32 fabrics were examined. Based on the results, channeled polyester, cotton and polypropylene were determined as the most promising fiber types for the final product.TUBITAK Textile Research CenterTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The financial support provided by the TUBITAK Textile Research Center (TUBITAK-TAM) is gratefully acknowledged (The Project Code: TUBITAK TAM 2005-01

Fabrication of Woven Honeycomb Structures for Advanced Composites

A honeycomb woven fabric was designed and produced on a sampling loom. After weaving cells in the fabric were opened by polytetrafluoroethylene (PTFE) sticks and an epoxy resin was applied to fabric. For comparison half of the fabric sample was impregnated with resin without opening the cells. Resulting fabric samples were subjected to low-velocity impact test by using drop weight impact testing machine, CEAST Fractovis Plus – 7526.000. To evaluate the impact behaviour of the samples the contact force, contact time, deflection, and absorbed energy values were recorded by data acquisition system (DAS). The energy absorbed by honeycomb structure was around 7 Joule. The energy absorbed by flat sample, on the other hand, was too low and out of the detection range of the testing equipment

ADSORPTION/DESORPTION AND BIOFUNCTIONAL PROPERTIES OF OLEUROPEIN LOADED ON DIFFERENT TYPES OF SILK FIBROIN MATRICES

WOS: 000405119400013The objective of this study was to investigate the adsorption/desorption behavior of oleuropein on different types of silk fibroin matrices including silk fibroin microfibers (MF), regenerated silk fibroin (RSF), and silk fibroin nanofibers (NF). Nanofibers with an average diameter of ranging between 24 and 326 nm were successfully prepared using the electrospinning technique. The effects of the silk fibroin concentration, the voltage applied and the distance between needle tip and collector plate on the morphology of the NF were investigated. The adsorption capacities of MF, RSF and NF were determined as 104.92, 163.07 and 228.34 mg oleuropein per gram of material, respectively. The percentage of initially adsorbed oleuropein that was desorbed was 86.08, 91.29 and 96.67% for MF, RSF and NF, respectively. NF and RSF discs loaded with oleuropein were subjected to disc diffusion assays to determine their antibacterial activity against test microorganisms Staphylococcus epidermidis (Gram +) and Escherichia coli (Gram -). The results showed that both biomaterials possessed antibacterial properties after loading with oleuropein. Wound scratch assays using oleuropein released from NF revealed an enhancement of cell migration, indicating a wound healing property of the material. In conclusion, the NF can be utilized as a biofunctional polymeric material with better performance for the adsorption and desorption of oleuropein compared with MF and RSF.Natural Products Research Development Unit (NPRDU) located in Technology Development Zone [DUA01/2010]The support (DUA01/2010) from Natural Products Research Development Unit (NPRDU) located in Technology Development Zone for the thesis study of Mr. Ali Bora Balta is gratefully acknowledged