| It is a well known fact that the quality of a fabric is tied to the non-uniformity of fabric properties. Although methods have been suggested to measure certain physical properties of woven or knit fabrics (mass, handle, strength, comfort, permeability), there has been no single method that is industrially accepted to characterize and quantify distribution of some of these fabric properties or non-uniformities. Therefore, the purpose of this research was to investigate and suggest a new method to fill this need. During this research, data about fabric properties were obtained either directly from images of fabric appearances or indirectly from on-line measurements of yarn diameters. The yarn diameters captured through a line-scan camera were mapped into a 2-D fabric matrix by assigning each point of the yarn to a specific location (x, y) within the 2-D fabric matrix. The gray-scale image of a 2-D fabric matrix was called a virtual fabric and provided the basic information on the uniformity of the fabric property. Variance-area curves were developed to characterize and quantify non-uniformity of actual and virtual fabrics in two dimensions. Certain irregularity features such as vertical and horizontal streaks and random cloudiness produced variance-area curves that are dependent on the shape of the unit area. Thus the difference between these curves became a new way to measure isotropy features of fabric properties. Theoretical relationships between yarns and their virtual fabrics were derived using only the internal correlation information of the given underlying yarns. |
