Dimensional stability of cotton, tencel and tencel/cotton blend plain weft knitted fabrics

Abstract

Pure cotton, 33/67 tencel/cotton, 67/33 tencel/cotton, and pure tencel yarns of 30 Ne count have been produced in the cotton spinning system and then used for knitting plain weft structure with three ranges of tightness factor to study their dimensional stability. Then knitted fabrics are subjected to dry, wet and tumble dry relaxations. Courses per inch(cpi), wales per inch(wpi), fabric thickness and areal density are measured at the end of each relaxation. Constants k₁, k₂, k₃, k₄ values for stitch density, cpi, wpi and loop shape factors are calculated using measured stitch length. Test results are subject to multilevel factorial analysis to determine factor contribution to the dimensional changes. It is found that the fibre contribution to the shrinkage is very less as compared to the contribution made by stitch length and relaxation treatments. Similarly, the quantum of length and width shrinkage is determined primarily by the stitch length (tightness factor). This is also confirmed by the calculation and comparison of loop shape factor. Thickness of the fabric is influenced significantly by relaxation treatment and fibre composition. Areal density is primarily determined by relaxation treatment and stitch length rather than by fibre composition. Hence, it is concluded that tencel and cotton are similar in dimensional characteristics.