Laddering Propagation in Weft Knit Fabrics

We use weft knit fabrics every day, as their compliance makes them ideal for clothes that are easy to put on and can conform to our bodies. However, the same structure that grants weft knits their stretchiness can also cause them to fail catastrophically; the breaking of a single yarn can lead to large visible holes which are caused by unsupported loops that propagate vertically and create a laddering effect. Using experiments to investigate this phenomenon, we first identify biaxial loading conditions that lead to laddering in plain knit architectures. Then, we explore strategies that we can use to manipulate this laddering effect. These include cut location along the stitch and horizontal transfers. As such, our study provides a framework not only to understand, but also to manipulate failure modes in soft wearables.