Image-based analysis of single jersey loop parameters

Abstract

Quality Control is crucial when it comes to fine and technical knits. Digital Twins are common in product design and are necessary for heat and mass flow simulations of textile fabrics. In both cases primarily, the exact geometry of the knitted loop is necessary for following processes. Wale spacing W and course spacing C are the essential geometrical characteristics of the representative unit cell of single jersey fabrics. The loop parameters can be obtained manually by counting loops per unit length or by microscopic measurements, which both are time consuming and are not applicable in integrated digital processes. Therefore, a new method for automatic extraction of major loop geometry parameters is described. A state-of-the-art method, which analyzes the microscopic images automatically, works with Fourier-Transformation of the image brightness and is used as a benchmark. The new loop-based method extracts the geometrical data from the distances between the center points of the loops. The methods are evaluated on single jersey fabrics of three different yarns. In addition, the impact of magnification on the measurement is shown for one fabric. The new method gives same results as manual measurements and even more precise results as the benchmark method.