Effect of Structural Parameters on the Auxetic Behavior of Weft-Knitted Fabrics Based on Foldable Structures

Abstract

Auxetic materials refer to materials with a negative Poisson’s ratio (NPR). They expand when stretched and become slimmer when compressed. Due to the special features of auxetic materials, they are used in a wide range of industrial applications including medical, fashion and clothing, composite, sports, and protective applications. This study aims to design and develop auxetic weft-knitted fabrics based on a horizontal zigzag structure with different structural patterns and investigate the influence of various parameters on their auxetic behavior. Auxetic fabrics with three patterns and three loop lengths were knitted using polyester yarn with different counts. Subsequently, the auxetic behavior of each fabric sample was examined. The results denote that the negative Poisson’s ratio decreases with increasing strain. The effect of the fabric knit pattern with different angles on the auxetic behavior is different in the course and wale directions. Fabrics with higher loop lengths have a higher initial negative Poisson’s ratio (NPR), while fabrics with smaller loop lengths exhibit auxetic behavior in a wider strain range. Furthermore, optimizing the fabric structure and dimensional parameters such as yarn count and loop length can enhance auxetic behavior. This research provides a useful study for optimizing auxetic fabric properties by changing structural parameters and developing innovative applications for materials with special mechanical properties.