Geometrical parameters of yarn cross-section in plain woven fabric

126-131<span style="mso-ansi-language: EN-IN;mso-bidi-language:FA">To study the effect of yarn twist on the geometrical parameters of yarn in a plain woven fabric such as its cross-sectional shape, the samples with various twist levels of warp and weft yarns have been woven and the yarn cross-section parameters are measured using their images obtained by Projectina microscope. The image processing analyses show that the shape of yarn cross-section in the fabric is affected by the twist level. The statistical analysis shows that the increase in yarn twist factor (atex) from 0 to 4600 changes the yarn cross-section shape into a lens shape and then elliptical shape and finally circular-like shape. The major diameter of the elliptical shape of the yarn cross-section decreases as the yarn twist increases, while the minor diameter of the elliptical shape of yarn cross- section increases as the yarn twist increases. The results also show that the twist of one group of yarns (warp) affects the cross-sectional shape of other group of yarns (weft). The ellipticity ratio of the yarns (minor diameter divided by major diameter) increases from 0.35 to 0.86 as the yarn twist factor increases from 0 to 4600. </span

Investigation of Circular Woven Composite Preforms for Composite Pipes

The main traditional technique for commercial manufacturing of composite pipes is filament winding in which the winding angle and the discontinuity of the structure (caused by starting and ending points of the winding process) are two important matters of concern. In the present study, circular woven fabric with its orthogonal net-shaped continuous structure was produced from polyester yarns. Fabric was wet with epoxy and hand lay-up was used to manufacture the composite pipes. Composite pipes were subjected to internal hydrostatic pressure and their burst strength was recorded. In addition, tensile strength of flat laminas was assessed in the warp and weft directions. We estimated and analysed the failure strength of composite pipes using Tresca’s failure criterion and Finite Element (FE) modeling. The experimental burst strength was almost 23% more than the FE model and 77% more than the theoretical estimate

Thermal properties of conductive nanocomposite core-shell filament yarns

380-386<span style="font-size:9.0pt;mso-fareast-font-family:SimSun;mso-bidi-font-family: " times="" new="" roman";mso-fareast-language:zh-cn;mso-bidi-language:th"="" lang="EN-GB">Thermal properties of conductive nanocomposite core-shell filament yarns have been investigated as a structure of a textile for the purpose of generating heat from an electrical power source. A fine copper monofilament is coated with a composite of polypropylene and various filler content of copper nanoparticles by an injection molding process to study the thermal properties of yarn as a function of filler shell content. Electrical analogy of Fourier’s law in thermal circuit has been used for development of a theory for thermal parameters. Then theoretical approaches are compared with modeling results obtained by ANSYS software and experimental results. Results reveal that although increase in filler content causes an increase in electrical and thermal conductivity of composite shell of yarn, heat generation in shell is negligible compared to that in core. Furthermore, results reveal that optimum value of filler fraction for desirable heat transfer is achieved at = 0.065. </span