The fabrication of auxetic fabrics by using conventional yarns and machinery has gained extraordinary interest from researchers in recent years. However, to date this approach has only been adopted to fabricate auxetic knitted fabrics and uni-stretch auxetic woven fabrics. This paper reports a study that aimed to develop a new class of bi-stretch woven fabrics with auxetic behavior using conventional elastic and non-elastic yarns, and available weaving machinery. Bi-stretch auxetic woven fabrics were firstly designed based on a foldable geometry possessing negative Poisson's ratio by consideration of different design parameters, including the yarn float length, the placement of tight and loose weaves, and the arrangement of elastic and non-elastic yarns in the weft direction, and then fabricated on a dobby weaving machine equipped with multiple weft supplies and a separately controlled second beam assembly attachment. The fabricated fabrics were finally tested on a tensile machine to assess their auxetic behavior in both the warp and weft directions. The results showed that the bi-stretch woven fabrics developed exhibit negative Poisson's ratio up to À0.36 and À0.27 when stretched along the warp and weft directions, respectively, and could be applied for clothing applications that require enhanced shape fit and comfort.

Fabrics with zero or negative Poisson’s ratio are referred as auxetic fabrics, which have the unusual property of lateral expansion or zero expansion upon stretch. The use of conventional materials and machinery to produce auxetic fabrics has gained the interest of researchers in recent years. However, this approach is limited to knitted fabrics only. The development of auxetic fabric using conventional yarns and weaving technology is a research area that is still unaddressed. This paper reports a study on the development of a novel class of stretchable auxetic woven fabrics by using conventional yarns and weaving machinery. The phenomenon of differential shrinkage was successfully employed to realize auxetic geometries capable of inducing auxetic behavior in woven fabrics, and a series of auxetic woven fabrics were fabricated with elastic and non-elastic yarns and a dobby machine. The uni-axial tensile tests showed that auxetic woven fabrics developed exhibited zero or negative Poisson’s ratio over a wide range of longitudinal strain.

This paper reports a development of bi-stretch auxetic woven fabrics by using non-auxetic yarns and weaving technology. The fabric structure is first designed based on a re-entrant hexagonal geometry by combination of loose weave and tight weave in a woven fabric structure, and then fabricated on a rapier weaving machine by using both non-elastic and elastic yarns. Two variations of the fabric are produced by using different elastic yarn arrangement in weft direction. The designed auxetic geometry is finally achieved after a washing process due to creation of non-uniform contraction or shrinkage profiles within the fabric structural unit cell. The testing results showed that the developed fabrics exhibit negative Poisson ratio effect in both weft and warp directions in a large range of tensile strain.

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Auxetic fabrics made of nonauxetic yarns have gained increasing interest of textile scientists. Most recently, single-layered bistretch auxetic woven fabrics made of nonauxetic yarns based on parallel in-phase zigzag foldable geometry have been reported to have auxetic behavior when stretched along both principal directions. It is also reported that this geometry can possibly be realized into double-layered woven fabrics. In addition, it is suggested that the phenomenon of differential shrinkage can be exploited to realize another variation of foldable geometry such as out-of-phase zigzag foldable structures into woven fabrics. Therefore, herein, two possibilities aimed to be explored are double-layered auxetic woven fabric based on parallel in-phase zigzag foldable geometry and single-layered fabrics based on out-of-phase zigzag foldable geometry that are developed using the phenomenon of differential shrinkage to realize these geometries into the woven fabric structures. Five different auxetic woven fabric samples are fabricated using elastic and nonelastic yarns on a conventional weaving machine and tested along two principal directions. The testing results show that all the developed fabrics have auxetic behavior in both principal directions, and the placement of weaves and weft yarn arrangements has an obvious effect.