Theoretical Porosity of Elastic Single Jersey Knitted Fabric Based on 3D Geometrical Model of Stitch Overlapping

Abstract

To improve the dimensional stability of weft knitted fabrics, spandex yarns are incorporated with the base yarn by the plaiting technique. Adding spandex leads to stitch overlapping, increases the fabric thickness, and affects the pore’s size and distribution. This in turn affects the geometrical and physical properties of weft knitted fabrics such as air permeability. In this paper, the theoretical 3D modeling of stitch overlap, maximum set, and open structures is presented by using AutoCAD software. Fabric thickness was divided into several sections, and the theoretical porosity at each section was analyzed and calculated. Furthermore, single jersey knitted fabrics SJKF with and without spandex were produced to obtain overlapping (by using spandex weight percent, SWP 8%), and open structures. The calculated and theoretical overall porosity were calculated and compared. The study showed the influence of stitch overlapping on fabric porosity. Moreover, the results show that the proposed model captured to some extent the change in fabric porosity as its structure changes.

Keywords

• single jersey knitted fabrics
• geometrical model
• stitch overlapping
• porosity
• spandex weight percent
• yarn diameter
• kidney shape of fiber cross-section