Bi-stretch auxetic woven fabrics based on foldable geometry

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 -0.36 and -0.27 when stretched along the warp and weft directions, respectively, and could be applied for clothing applications that require enhanced shape fit and comfort.