Fabrication and Mechanical Characterization of Dry Three-Dimensional Warp Interlock Para-Aramid Woven Fabrics: Experimental Methods toward Applications in Composite Reinforcement and Soft Body Armor

Recently, three-dimensional (3D) warp interlock fabric has been involved in composite reinforcement and soft ballistic material due to its great moldability, improved impact energy-absorbing capacity, and good intra-ply resistance to delamination behaviors. However, understanding the effects of different parameters of the fabric on its mechanical behavior is necessary before the final application. The fabric architecture and its internal yarn composition are among the common influencing parameters. The current research aims to explore the effects of the warp yarn interchange ratio in the 3D warp interlock para-aramid architecture on its mechanical behavior. Thus, four 3D warp interlock variants with different warp (binding and stuffer) yarn ratios but similar architecture and structural characteristics were engineered and manufactured. Tensile and flexural rigidity mechanical tests were carried out at macro- and meso-scale according to standard EN ISO 13 934-1 and nonwoven bending length (WSP 90.5(05)), respectively. Based on the results, the warp yarn interchange ratio in the structure revealed strong influences on the tensile properties of the fabric at both the yarn and final fabric stages. Moreover, the bending stiffness of the different structures showed significant variation in both the warp and weft directions. Thus, the interchange rations of stuffer and binding warp yarn inside the 3D warp interlock fabric were found to be very key in optimizing the mechanical performance of the fabric for final applications.

Enhancing the Ballistic Performances of 3D Warp Interlock Fabric Through Internal Structure as New Material for Seamless Female Soft Body Armor Development

This paper investigates the effects of warp yarns ratios on the ballistic performances of three-dimensional (3D) warp interlock p-aramid fabrics. Four 3D warp interlock variants with different binding and stuffer warp yarns ratios were designed and developed. Except for warp yarns ratios, similar fabric parameters and manufacturing conditions were considered. Two-dimensional (2D) woven fabric having similar material characteristics and recommended for female seamless soft body armor are also considered for comparisons. Five ballistic panels, one from 2D plain weave fabric and the rest four from the other 3D warp interlock variants were prepared in a non-angled layer alignment and non-stitched but bust-shaped molded form. The ballistic test is carried out according to NIJ (National Institute of Justice) standard-level IIIA. Back Face Signature (BFS) was then modeled and measured to compute both trauma and panels’ energy-absorbing capability. The result showed significant ballistic improvement in the 3D warp interlock variant with optimum warp yarns ratios over traditional 2D plain weave fabrics. 3D warp interlock fabric panel made with 66.6% binding and 33.3% stuffer warp yarn ratio revealed both lower BFS depth and higher energy absorbing capacity (%) than other panels made of 2D plain weave and 3D warp interlock fabric variants.

Yarn degradation during weaving process and its effect on the mechanical behaviours of 3D warp interlock p-aramid fabric for industrial applications

Three dimensional (3D) warp interlock fabric becomes a promising structure due to its good mechanical performances. However, its complex manufacturing process can cause severe yarn damage and affects its overall final performances. The current study addressed the effects weaving process and warp yarn ratios on the multi-filaments yarn degradations and its mechanical performances while 3D warp interlock fabric manufacturing. Four different 3D warp interlock variants having similar fabric architecture, and yarn densities but different warp yarns interchange ratios were manufactured using 930dTex high-performance multi-filament (Twaron® f1000). The multi-filaments yarns at different weaving processes were tested for their tensile properties. The results show that the average tensile strength of twisted yarns show a decrement of 5.68% as compared to the bobbin yarns. Meanwhile, warping process also showed a 16.11% maximum breaking load reduction as compared to the bobbin yarn. Besides, the tensile strength of binding yarn after weaving process for samples 3D-8/0, 3D-8/4, and 3D-8/8 was reduced by 12.79%, 5.22%, and 14.22% respectively as compared to the yarn after warping process. In conclusion, yarn degradation inside the 3D woven structure was affected not only by the various process parameters but also by the type of fabric architecture made with different warp yarn ratios. These phenomena ultimately bring a great influence both on the yarn and overall mechanical performance of the final products. For this, further studies are planned to investigate the multi-filaments yarn degradation effect on the ballistic performances fibrous material as it is directly linked to the yarn performance.

New Textile Composite Solutions for Armouring of Vehicles

In today’s scenario, numerous studies have shown a great interest on 3D woven structures like 3D warp interlock fabric as a fibre reinforcement for composite material to provide a better impact than 2D laminated fabrics with unlinked structures in the thickness. The impact energy absorption capacity depends on different and independent parameters, including the shape and speed of the projectile, the type of fibrous structure (geometry), the type and nature of the threads (raw material, linear density, and twisting value), and the type of impregnation of the composite material. As part of our research work on hard impact protection solutions, the interest of textile composite structures, in particular those integrating 3D warp interlock fabrics, has been revealed. Based on the result, protection solutions with such fabric structure revealed larger dynamic deformation capacity for absorbing the impact energy as compared with not only a ceramic material facing a 12.7 mm ammunition (mass 43 g) at 610 m/s but also those solutions made with metallic materials facing a FSP (diameter 20 mm, mass 54 g) at 630 m/s and 1600 m/s. For each of these different threats, a specific type of composite material has to be used. These composite material solutions are mainly defined to respond to the appropriate mode of impact behaviour.