Dyeing of recycled Poly(lactic acid) fibers from disposable packages flake with low energy consumption and effluent

Abstract

Poly(lactic) acid as a biodegradable polymer has attracted a lot of attentions due to its environmental merits and availability in sufficient quantities for use in the packaging industry. Recycling of poly(lactic) acid and converting it to a new product, instead of a compost material or primary monomer, is an economical and environmental solution. In this paper, recycled poly(lactic) acid fibers melt-spun from disposable package flakes were dyed by using three disperse dyes having different molecular weights and their dyeing behavior and fastness properties have been studied. Dyeing temperature, time and concentration were fully investigated. The results showed that with an increase in the temperature from 80 °C to 120 °C, the amount of dyeing exhaustion rate increased for different disperse dyes. The recycled poly(lactic) acid fibers exhibited a good exhaustion rate in a short time (20 min), low concentrations (0.5% on weight of the fabric) and low temperature (80 °C). The good to excellent washing fastnesses between 4 and 5 were observed for the recycled poly(lactic) acid fibers which were dyed by the three selected disperse dyes under the optimized conditions. Accordingly, it could be considered that the recycled poly(lactic) acid fibers have a great capability to be dyed with low damage, energy consumption, costs and effluent with disperse dyes.