The aim of this study was to understand the low-velocity impact energy absorption mechanism of the developed two-dimensional multistitched multilayer E-glass/polyester-woven composites. It was found that the specific front and back face damaged areas of the two-dimensional multistitched E-glass/polyester-woven composites were smaller than those of the two-dimensional unstitched structures. When the stitching density increases, the front and back face damaged areas generally decrease. In addition, when the number of stitching directions increased, the front and back face damaged areas decreased. Therefore, stitching density, stitching directions, stitching yarn, and stitching type on the composite structures were considered as important parameters. Impact load caused a small indentation in the center of front face and resulted in fiber splitting and fiber breakages in the center of the back face of the structure. On the surrounding area of the front and back face damaged zones of the structures, fiber-matrix debonding and matrix breakages were observed. These results indicated that multistitching suppressed the impact energy to a small area of the composite structure. Thus, the two-dimensional Kevlar®129 or E-glass-multistitched E-glass/polyester-woven composite structures showed better damage tolerance performance compared to the unstitched composite structures.

TurkeyFlocked fabrics are textile-based products which have been used in outwear and home textiles since the 1960s [1]. Flock fiber length is between 0.5-2.0 mm, flock fiber fineness is from 14 micron and flock fiber material is polyamide or viscose, generally used as a flock layer for outwear and home textile flocked fabrics. The substrate fabric is mostly polyester/cotton-mixed fibers because of the capability of moisture retention. Flocked fabrics are characterized by their warm appearance and soft handle, and the figured flocked fabrics are obtained by the application of the specific effects [2][3][4][5].Flocked fabrics are produced by coating the substrate fabric with aqua-based acrylic or polyurethane and polyvinylchloride adhesives, orienting the flock fibers substantially vertically with respect to the substrate under the influence of an electrostatic field. After that, coated substrate with flock fibers is cured in an oven [1,4,5].It has been stated that the harsh handle polyamidebased flock fibers are more favorable due to their good color fastness, brightness and abrasion resistance than the soft handle viscose-based flock fibers which have poor color fastness and abrasion resistance. In addition, the fastenings between the flock fibers and adhesive are provided with water repellent treatments [6][7][8].Flock fabric in daily use has some problems. There is a tendency of delaminating of the flock fiber layer from the substrate under the rubbing and abrasion movements in cleaning and general use. In the literature, there are some extensive studies about the abrasion resistance of woven and knitted fabrics. These studies concentrated on the abrasion behavior of chenille fabrics [9][10][11][12][13][14]. However, studies about the abrasion behavior of flocked fabrics are limited. 1 The aim of this study was to characterize certain flocked fabrics [15] by measuring the abrasion resistance. For this purpose, Martindale abrasion behavior of flocked fabrics and token rubbing behavior on dry and wet form were determined.Abstract Flocked fabrics are particularly used in outwear and home upholstery since they are comfortable and soft. In this study, Martindale abrasion and token rubbing properties of the flocked fabrics were investigated and characterized. It was observed that the surface abrasion properties of the flocked fabrics varied depending on the flock fiber density and flock fiber length. The abrasion resistance of flocked fabrics was increased by increasing flock fiber length and decreasing flock fiber density. The surface rubbing properties of flocked fabrics showed similar tendencies with the abrasion properties. However, the flocked fabrics showed more resistance to rubbing in dry form than wet form. These results were in agreement with the optical microscope images.

The aim of this study was to experimentally determine the bending behavior of developed multilayered multistitched EGlass preform structures. For this reason, a bending rigidity test instrument based on the cantilever test principle was used. A bending rigidity test was conducted on all developed multilayered multistitched E-Glass preform structures. Yarn linear density and fabric density influenced the bending rigidity of single layer E-Glass fabric. The single layer fabric's bending rigidity depended on the off-axis angle orientations in the fabric plane. On the other hand, the bending rigidity of the multilayered unstitched E-Glass fabric structure depended on the number of fabric layers. The bending rigidities of the multilayered four directional hand and machine stitched E-Glass preform structures were high compared with one and two directional hand and machine stitched E-Glass preform structures. The bending rigidities of all heavy (6 step/cm) machine stitched E-Glass preform structures were high compared with light (2 step/cm) machine and hand (1 step/cm) stitched EGlass preform structures. In addition, the bending rigidities of all developed multilayered hand and machine stitched E-Glass preform structures were higher than those of unstitched preform structures due to stitching. In addition, the multilayered multistitched preform structures showed a low order of bending curvatures compared with the multilayered unstitched preform structures. The results indicated that the number of stitching directions and stitching steps substantially affected the bending rigidity of the developed preform structures. Stitching yarn type was also a parameter for the bending behavior of the multistitched preform structures. It was considered that the unstitched fabric structure could be easily formed whereas the directional stitched E-Glass preform structure became stiff and could not be easily formed.

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The aim of this study was to understand the pull-out properties of E-glass woven fabrics. For this purpose, low yarn linear density E-Glass-F1 and high yarn linear density E-Glass-F2 woven fabrics were used to conduct the pull-out tests. A developed yarn pull-out fixture was used to test short and long fabric sample dimensions. Data generated from the single and multiple yarn pull-out tests using E-Glass-F1 and E-Glass-F2 woven fabrics included fabric pull-out forces, yarn crimp extensions in the fabrics and fabric displacements. Yarn pull-out forces depend on yarn linear density, fabric density, fabric sample dimensions and the number of pulled ends in the fabric. Results showed that multiple yarn pull-out force was higher than single yarn pull-out force. Single and multiple yarn pull-out forces in high yarn linear density E-Glass-F2 were higher than those of low yarn linear density E-Glass-F1 fabric. It was found that the crimp ratio in the fabric and fabric lengths is an important structural parameter for yarn crimp extension. Fabric displacement resulting from the multiple yarn pull-out test was higher than that of the single yarn pull-out test. Fabric displacement generated from single and multiple pull-out tests depended on fabric sample dimensions and the number of pulled yarn ends. Future research will concentrate on the development of the analytical relationship between pull-out and yarn fabric structural parameters which could result in a better fabric structure for use in composite applications.