Auxetic materials are a type of novel materials exhibiting negative Poisson's ratio (NPR) with potentials for special applications. Herein, the aim is to optimize the auxetic yarn and fabric manufacturing processes, establish the understanding of the influence of yarn and fabric parameters on the auxeticity of the engineered materials and explore the potential applications of auxetic textile materials. The auxetic yarns are manufactured based on a conversional helical structure composing initially a super elastic polyurethane core and a high modulus Nylon 6,6 binder. A hollow spindle machine is used to produce the auxetic yarn with optimized twisting and delivery speeds. Stable helical yarns with auxetic properties are manufactured using the optimized parameters, and woven fabrics are produced from the selected auxetic yarns in both warp and weft directions. Experiments show that the maximum NPR of helical auxetic yarns reaches a remarkable level of −5.6, and the auxetic fabrics display notable geometric changes compared with the nonauxetic fabrics with the same structural parameters. The auxeticity demonstrated in the fabrics implies applications in areas such as filtration and impact protection.

中文翻译：

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辅助纱线和机织织物的制造和评估

辅助材料是一种新型材料，具有负的泊松比（NPR），具有特殊应用的潜力。在此，目的是优化发条纱线和织物的制造工艺，建立对纱线和织物参数对工程材料发条性的影响的理解，并探索发条纺织品的潜在应用。所述膨松纱基于最初由超弹性聚氨酯芯和高模量尼龙6,6粘合剂组成的转化螺旋结构来制造。空心锭子机用于生产具有最佳加捻和输送速度的膨松纱。使用优化的参数制造出具有稳定的膨胀特性的螺旋纱，机织织物是从选定的经向和纬向的膨体纱生产的。实验表明，同等结构参数的非膨松织物相比，螺旋膨松纱的最大NPR达到-5.6的显着水平，并且膨松织物的几何变化显着。织物中显示出的膨胀性意味着在过滤和冲击防护等领域的应用。