Design and manufacture of knitted tubular fabric with auxetic effect

Auxetic materials refer to materials that exhibit a negative Poisson’s ratio. They behave directly opposite to conventional materials by becoming wider when stretched and narrower when compressed. The unique property of this group of materials has led to them gaining a wider range of applications. This paper presents a study on the use of a flatbed knitting machine to fabricate and experiment on an arrow-headed auxetic tubular fabric. The study used three kinds of yarns: nylon (PA), PES, and cotton as the materials for knitting the tubular samples. Three variations of an arrow-head design (4 × 4, 6 × 6, and 8 × 8) were also used as the three main structural patterns. The results reveal that the ‘6 × 6’ structure gives the best auxetic effect among the three and the nylon (PA) yarn had the best auxeticity.