Assessment of the life expectancy and environmental performance of polylactic acid compared to cotton and polyethylene terephthalate fabrics

摘要

The need to satisfy the increasing global demand for textile and clothing material due to population growth and changes in fashion trends have led to the manufacturing of short life span textiles. Current fabrics such as cotton and polyethylene terephthalate (PET) all have deep environmental impacts. This study examines Polylactic acid (PLA) fabric derived from corn as a contending replacement for cotton and polyethylene terephthalate. The use phase has been identified as the dominant contributor to environmental impacts and consequently this research has focused on how the laundry regime (wash performance) affects the life expectancy and the mechanical properties of PLA, PET and Cotton. This study excludes daily wear, dirt and stains.By testing the constituent fabrics after each laundry regime, the results showed a more significant level of impact on cotton than PLA fabric in different laundry treatments with or without softener. There was no effect on PET. The load-extension behaviour showed that PLA and cotton withstood ten laundry cycles before showing any significant signs of damage; however, PET fabric retained its load-extension behaviour beyond 50 laundry cycles. From a practical standpoint, the result of this study suggests that tumble-drying should be avoided; however, the use of softeners during the laundry and air-drying seems to provide stability for PLA and PET fabrics. The influence on the cotton fabric was more from the drying process than the use or absence of softener, buttressing the fact that tumble-drying should be avoided if possible. The life expectancy of PLA fabric showed a lower lifetime (35 washes/lifecycle) compared to PET and cotton (42 and 43 washes/lifecycle respectively). With these results, a comparative lifecycle assessment was conducted during the life expectancy and after a typical school t-shirt use of 75 laundry regimes, PLA offered environmental benefits compared to PET and Cotton. The result also revealed that the environmental impact of cotton decreased by 2%, PET decreased by about 1.2% while PLA increased by 3% when the laundry lifetime was increased to 75 wash cycles. The results obtained in this study showed that enhancing the fabric to increase its laundry lifetime does not automatically lessen the environmental impacts. Nevertheless, it has proven that even a small rise in the lifetime of PLA fabric can make it comparable and competitive with PET and cotton. In addition, the similarities in properties with PET makes PLA a valuable substitute, with a sustainable low environmental burden. In comparison to cotton (Energy Demand 36.5%, Water Consumption 53%, and Global warming potential Contribution 43%), PLA (Energy Demand 28.5%, Water Consumption 21% and Global warming potential Contribution 22%), demonstrates a better alternative in all aspects and is recommended as a suitable replacement due to its potentially low water and energy use, and CO2 emission.