The effect of mold shape on the warp-knitted fabric formability

Fabric formability refers to its deformation on the 3D mold during the forming process. Formability is vital in the clothing, textile, and composite industry. This means that the formability of the fabrics used as reinforcement for the flawless (such as wrinkle) and cost-effective composites parts is examined. In this research an empirical index for the formability of fabrics based on surface strain is defined. Then, a theoretical index is proposed based on geometrical analysis of inelastic sheet forming. The effect of mold geometry on the fabric formability is also investigated. The results demonstrated that the mold dimensions do not have a remarkable effect on the formability, but the shape of the mold is effective on formability. Increasing the angles of the corners lead to reduce the index of formability and the number and length of the wrinkling also reduce. Overall, the trends of theoretical and experimental results of the formability index are similar.