Effects of different production processing stages on mechanical and surface characteristics of polylactic acid and PET fibre fabrics

This paper reports study on the polylactic acid (PLA) and polyester (PET) knitted fabrics mechanical and surface characteristics at low-stress and the influence of typical commercially applied different production processing stages on the properties. The KES-FB is used for the investigation of low-stress bending, compression, tensile, shear and surface characteristics. The results show remarkable changes after each processing stage, such as scouring, drying, dyeing, heat setting and softening, in mechanical and surface characteristics of PLA and PET fibre knitted fabrics. PLA knitted fabrics represent higher values in bending, shear and surface properties after different processing stages as compared to PET knitted fabrics. The values of bending rigidity (B), bending hysteresis (2HB), shear stiffness (G), and shear hysteresis (2HG and 2HG3) have been significantly decreased after the scouring treatment. There is a considerable decrease in B, 2HB, G, 2HG and 2HG3 values and an improvement in tensile elongation (EMT) after dyeing of PET and PLA fabrics. A slight reduction in shear and bending properties of polylactic acid fibre fabrics shows that softening treatment decreases the inter fibre and inter yarn friction. LT (linearity of load-extension curve), RT (recovery from tensile deformation), LC (linearity of compression curve) and RC (recovery from compression deformation) properties are not found quite sensitive for different production processing stages in case of both the fabrics