Bi-stretch auxetic woven fabrics based on foldable geometry

Abstract

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.

Auxeticity from the Folded Geometry: A Numerical Study

“…By parameterizing the folded fabric previously investigated by Cao et al and Zulifqar et al, a folded model was built, as shown in Figure . The folded structure can be considered as a thin‐walled structure without any voids.…”

“…Grima et al demonstrated that the graphene could be made to mimic the behavior of the wrinkled paper model to exhibit auxetic properties. In particular, the folded geometry, as shown in Figure a, has been successfully transformed to NPR fabrics (Figure b) by Cao et al and Zulifqar et al This kind of fabrics could also be considered as a nonporous sheet or membrane and they were realized by creating the phenomenon of differential shrinkage into a fabric structure to enable different sections of a fabric unit cell to endure different levels of shrinkage upon relaxation. The relaxed fabric in Figure b can be divided into two sections: the loose weave zigzag area and the tight weave zigzag area.…”

“…The former area deforms more easily than the later one under stretching. The previous work has performed details on the fabrication and mechanical behaviors of the fabrics and has revealed that auxetic behavior could be obtained under both warp and weft directional tensions. The work also suggested that these fabrics could be applied for clothes that require enhanced shape fit and comfort.…”

Investigation of the change of the shrinkage properties in contradiction to the change of the composition of cotton polyester spandex denim fabrics

“…Cao et al 12 reported that the optimization of spinning parameters could influence the hairiness properties of polyester cotton vortex yarn.…”

Detecting the spandex injuries and therapies of stretched garments

“…17 Researcher also reported that manmade fibers are made up of different polymer ingredients and these ingredients are made up of long chain polymer. 18…”