Effect of twist level on the mechanical performance of S-glass yarns and non-crimp cross-ply composites

Abstract

High modulus/high strength continuous fibres are used extensively for manufacturing textile preforms, as a reinforcement, for composites due to their excellent specific properties. However, their brittle behaviour and tendency to separate easily into individual filaments or bundles can lead to damages during manufacturing processes such as weaving and braiding. Thus, the critical step in the development of an optimal yarn for textile-reinforced composites is to find an optimum twist, which results in a minimum loss of properties of the composite laminates, while maintaining good processability and sufficient strength for textile and/or composite manufacturing. In this study, twist level has been varied to improve the handling and tensile properties of S-glass yarns (i.e. tensile strength). Varying levels of yarn twist (15–40 twists metre−1) were employed to study its impact on the tensile properties (i.e. tensile strength, modulus, elongation at break etc.). Furthermore, the effect of twist on the tensile properties of non-crimp cross-ply composites produced via vacuum infusion process was studied. It was observed that mechanical performance (i.e. tensile strength properties) of twisted yarns is improved up to 30 twists metre−1 while it is deteriorated at 40 twists metre−1. At yarn level, the experimental results were compared with theoretical estimations utilizing existing models for twisted yarns properties. Discrepancies were observed between experimental and theoretical results especially for high level of twist. The tensile strength and elongation of S-glass cross-ply composites at all levels of twist were higher compared to the composite laminates manufactured by using non-twisted yarns. At composite level, the experimental results were also computed employing rule of mixture and good agreement was observed between experimental and predicted results.

Impact of Drying Regimes and Different Coating Layers on Carboxymethyl Cellulose Cross-Linked with Citric Acid on Cotton Thread Fibers for Wound Dressing Modification

“…The extension increased CT lateral pressure and compaction and, as a result, CT became denser and more coherent to strain. CT has a slightly loose twisting orientation that allows CMC + CA to penetrate and coat individual fiber surfaces, which further improves CT load bearing capacity by intercepting higher loads, thus leading to the improvement of elongation and avoiding early breakage [ 51 ].…”

Mechanical Properties of Twisted Cellulose Nanofiber-Reinforced Silk Yarns

“…The long length of filaments enables low twist levels to maintain the components together . Thus, theoretical studies have shown that the tensile strength of filament yarns was the maximum when they were untwisted and decreased with the twist level. − This behavior was experimentally shown by Yoshida et al using ramie-twisted yarns and by Dalfi et al, who demonstrated the maximum strength of S-glass yarns at a low twist level (30 twists per meter (tpm)). Discrepancies in this behavior have been observed in other studies, where the tensile strength of the yarns reached a maximum at higher twist levels.…”

A spinning method for low-torsion composite yarn with basalt fibers and staple cotton fibers

“…Generally, spinning composite technology has been used to compensate for the disadvantages of staple fibers and basalt fiber together. Unfortunately, problems of large modulus differences between staple fibers and basalt fiber exist, with high-modulus basalt fiber filaments breaking easily under high twist conditions (Kim et al, 2009;Li et al, 2018), while low-modulus staple fibers not cohesive yarns well in untwisted conditions (Qian et al, 2021;Dalfi et al, 2022).…”