Influence of hydroentangling variables on the properties of bi-layer polyethylene terephthalate–glass fabrics

Abstract

Two webs, the first containing 100% polyethylene terephthalate (PET) and the second 80% glass/20% PET, were integrated by hydroentangling to produce a coherent bi-layer fabric. A full-factorial experimental study at two levels was conducted to determine the influence of four hydroentangling variables (water pressure, conveyor speed, nozzle diameter and number of injectors) on the dimensional and mechanical properties of the fabrics. Each variable was known to contribute to the specific energy. Statistical analysis was conducted using analysis of variance and analysis of covariance to determine the main effects and interactions. In terms of fabric tensile strength, a significant interaction was found between the conveyor speed and nozzle diameter and also between the water jet pressure and the number of injectors. Statistical analysis enabled the levels of each variable to be selected to minimize the specific energy consumption, as it was found that fabrics produced using the same specific energy can exhibit significantly different properties. Scanning Electron Microscopy and X-ray microtomography confirmed the migration of fiber segments between the two web layers and revealed the nature of fiber interactions in the interface.