Ultraviolet resistance on weft knitted fabric coated by benzotriazoles

Abstract

Ultraviolet resistance upon four different types of weft knitted fabrics including Lacoste, Single Jersey, Rib and Interlock were experimentally measured and evaluated by ultraviolet–visible spectroscopy under effects of gauge, specific weight, fiber composition and finishing agent as benzotriazole derivatives. The results showed that ultraviolet protection factor (UPF) of Interlock sample reached the highest value at 42.7. Simultaneously, the higher gauge of Single Jersey knitted fabrics was, the better its ultraviolet protection exhibited. Also, insertion of polyester fibers or spandex fibers into cotton knitted fabrics with a certain ratio strongly increased UPF values. Notably, all UPFs of coated fabrics with a given content of benzotriazole were significantly improved and almost coated samples could undergo several washing cycles and still retain their inherent breathability. This work demonstrated that cotton knitted fabrics coated with benzotriazoles were excellently enhanced ultraviolet protection. Especially, the UPF values on Interlock or Rib specimens as well as Single Jersey samples blended with polyester/spandex fibers were found to be higher than 15.