Functional performance of thin Ag, SS, and Ti films on retro-reflective fabrics

Abstract

Retro-reflective materials are gradually increasing in popularity and use due to their safety properties, and aesthetic advantages. This study details an experimental procedure of the functional performance of silver (Ag), stainless steel (SS), and titanium (Ti) coatings of 150 nm in thickness on retro-reflective fabrics (with plain, twill and diamond weave structures) via magnetron sputtering. The deposited thin films were characterised using CIE L* a* b* values, SEM, contact angle, air permeability, thermal conductivity, anti-static, IR and UV protection. The results reveal that Ag coated fabric can transfer away body heat, hence ensuring a feeling of coolness. The Ag coated fabric samples have an overall good infrared (IR) protective property followed by SS, with Ti having a poor IR protective performance. All of the coated fabrics show excellent ultraviolet protection with 50+ UPF ratings. Furthermore, the coated fabrics have good anti-static properties which prevent the build-up of static charge that can cause discomfort to the wearer, especially in dry weather conditions. The deposition of Ag, SS or Ti nanoparticles on the surface of the fabric increases the hydrophobicity of the material or results in a fabric with low wettability as evident from the measured contact angles.