3D Fabrics for Technical Textile Applications

Two dimensional (2D) woven, braided, knitted and nonwoven fabrics have been used for the fabrication of soft and rigid structural composite parts in various industrial areas. However, composite structure from biaxial layered fabrics is subject to delamination between layers due to the lack of through-the-thickness fibers. It also suffers from crimp which reduces the mechanical properties. Triaxial fabrics have an open structure and low fiber volume fraction. However, in-plane properties of triaxial fabrics are more homogeneous due to bias yarns. A 3D woven fabric has multiple layers and is free of delamination due to the z-fibers. However, 3D woven fabric has low in-plane properties. Three dimensional braided fabrics have multiple layers and they are without delamination due to intertwine type out-of-plane interlacement. However, they have low transverse properties. A 3D knitted fabric has low fiber volume fraction due to its looped structure. A 3D nonwoven fabric is composed of short fibers and is reinforced by stitching. However, it shows low mechanical properties due to lack of fiber continuity. Various unit cell based models on 3D woven, braided, knitted and nonwoven structures were developed to define the geometrical and mechanical properties of these structures. Most of the unit cell based models include micromechanics and numerical techniques

Applications of Glass Fibers in 3D Preform Composites

E-glass three dimensional (3D) stitched preform composites have been developed for several industrial applications due to their high mechanical performance and damage tolerance properties. Although some in-plane properties of the stitched E-glass composite structure are slightly lower than in laminated composite, its mode-I delamination failure is improved. This was achieved by using the out-of-plane directional stitched fibers. Recently, some nanoparticles as single-walled nanotubes (SWNT) or multiwalled nanotubes (MWNT) or nanofibers (NF) were added to the glass fabric structure or stitched preform during consolidation process. This further enhances the thermo-mechanical impact properties of the E-glass fiber composites

Three- dimensional circular various weave patterns in woven preform structures

The aim of this study was to develop three-dimensional (3D) fully interlaced representative circular woven preform structures and to understand the effects of weave pattern and number of layers on 3D circular woven structures. Various 3D circular woven preforms were developed. Data generated from these structures included yarn-to-yarn space, density, yarn angle, yarn length and crimp. It was shown that the weave patterns affected the 3D circular woven preform structures. The yarn-to-yarn spaces in the 3D fully interlaced circular structures were high compared to the traditional 3D orthogonal circular woven structures in fabric circumference (fabric outside surface) due to the interlacement of the yarn sets. The 3D plain, twill and satin structures resulted in axial angle (a) in fabric length; circumferential angle (c), and interlaced radial angle (ri) in fabric circumference and fabric diameter due to the axial-circumferential and axial-radial interlacements. The weave patterns slightly affected the yarn angles. On the other hand, it was observed that the number of layers considerably affected the radial arc length and the radial length in wall thickness in the 3D circular woven structure. The interlacement on 3D plain, twill and satin circular woven structures resulted in axial crimp, circumferential crimp and radial crimp. The crimps in the 3D fully interlaced circular woven structures slightly depended on the types of weave pattern and the number of layers

Three-dimensional fully interlaced woven preforms for composites

The aim of this study was to develop three-dimensional (3D) fully interlaced and semi-interlaced representative woven preform structures and to understand the effects of weave pattern and number of layers on 3D woven structures. Various 3D woven preforms were developed. Data generated from these structures included yarn angle, yarn-to-yarn space and density, yarn length and crimp. It was shown that the weave patterns affected the 3D woven preform structures. The yarn-to-yarn spaces of the 3D fully interlaced and semi-interlaced structures were high compared to the traditional 3D woven structures (orthogonal, through-the-thickness and angle interlock) in fabric width due to the interlacement. The 3D plain, twill and satin structures resulted in warp angle (w) in fabric length and filling angle (f), and interlaced z-yarn angle (zi) in fabric width due to the warp-filling and warp-z-yarn interlacements. The weave patterns slightly affected the yarn angles. On the other hand, it was observed that the number of layers considerably affected the z-yarn arc length and the z-yarn length in thickness in the 3D woven structure. The interlacement on 3D plain, twill and satin woven structures resulted in warp crimp, filling crimp and z-yarn crimp. The crimps in the 3D structure fully interlaced and semi-interlaced woven structures slightly depended on the types of weave pattern and the number of layers

Shear characterization of para-aramid (Twaron (R)) fabric by yarn pull-out method

The aim of this study was to determine the para-aramid fabric shear by the pull-out method. For this purpose, Twaron (R) type fabrics were used. The fabric width/length ratio and the number of pull-out ends were identified as important testing parameters. It was found that fabric shear depended on fabric density. Fabric shear strength increased when the number of pulled ends increased. When the fabric width/length ratio decreased, fabric shear strength increased. The number of pulled ends and the fabric width/length ratios influenced the fabric shear rigidity. Also, shear jamming angles were found to be based on the number of pulled ends. The results showed that para-aramid fabric shear could be measured by the yarn pull-out test

Ballistic performance of multiaxis noninterlaced/non-Z E-glass/ polyester composites with soft backing aramid fabric structures

The aim of this study is to understand the energy absorption mechanism and identified failure modes of the developed multiaxis non-interlaced/non-Z Eglass/ polyester and 3D woven carbon/epoxy composites with soft backing para-aramid fabric structures. The damage zones of both structures were investigated after impact. 3D woven carbon/epoxy showed a small damaged area compared to that of the non-interlaced/non-Z Eglass/ polyester. This was because Z-fiber suppressed the impact load but the local area was severely damaged in the form of fiber and matrix breakages. There was no intra and inter fiber damage around the impacted area in the 3D carbon/epoxy composite whereas there was intra and inter fiber damage around the impacted area in the non-interlaced/non-Z E-glass/polyester

New Method of Weaving Multiaxis Three Dimensional Flat Woven Fabric: Feasibility of Prototype Tube Carrier Weaving

A prototype of multiaxis three dimensional (3D) flat weaving was constructed, and the feasibility of this type of weaving was studied. Several multiaxis 3D woven and 3D orthogonal woven unit cells were developed and fabricated for the trial of the preforms. Multiaxis weaving units were described and implemented based on the initial trial period. The performance of each unit cell was tested, and important processing parameters were found to be related to the multiaxis unit cell. It was found that this kind of weaving could be achieved for certain types of unit cell, the results of which can be considered to be encouraging