Towards UV-curable inkjet printing of biodegradable poly (lactic acid) fabrics

There has been growing interest in using poly (lactic acid) (PLA) fibres because of its natural-based origin and good biodegradability; however, its adoption within the textile industry has been limited to lower temperature wet and dry processing, because of its relatively lower glass transition temperature (T _g) and melting point (T _m). Here we report for the first time inkjet printing of heat-sensitive PLA fabrics using ambient temperature UV-curable inks as a way of overcoming the potential degradation at higher temperature. The UV cured inkjet printed PLA fabrics exhibited good performance characteristics such as acceptable colour fastness, relatively high colour strength, K/S, and comparable colour difference, ΔE, after washing to the thermally cured ink system, without affecting the physical and mechanical properties of the fabrics. In contrast thermally cured inkjet printed PLA fabrics exhibited significantly reduced bursting strength and stiffer handle attributed to the thermal degradation and lower fibre flexibility imparted at the higher temperature. Investigation of the radiation-cured printing approach indicates UV-curable inkjet printing may be considered as an alternative to conventional thermally cured pigment printing of heat-sensitive biodegradable PLA-based fabrics.