Effects of yarn bending and fabric structure on the bending properties of plain and rib knitted fabrics

This work deals with the bending properties of a series of plain and rib weft knitted structures made from cashmere yarns. Additionally, some plain weft knitted fabrics made from polyester textured yarns (PET) are included for comparison. The experimental results are discussed in terms of the structural characteristics (cover factor, fabric weight) and their effects on the bending properties. Theoretical analyses of the effects of yarn bending properties and fabric structure on the bending rigidity and frictional bending moment of the fabrics an based on our straight parallel yarns (SPY) model. In this model, the knitted structure is assumed to consist of a series of straight yarns that have some overlapping regions at the interlocking points. The estimation of fabric bending parameters is based on summing up the bending parameters of these straight yarns, which have some overlapping regions lying in the direction of bending. The estimated values from this model are compared with the values measured on a KES-FB pure bending tester; the predictions are in a reasonable agreement with the experimental data.