Mesta (Hibiscus sabdariffa) and polylactic acid thermally bonded fabric for sustainable shopping bags: modeling and optimization of functional properties

Abstract

A thermally bonded biodegradable fabric has been developed using mesta and polylactic acid fibers. The central composite rotatable design has been adapted to understand the effects of the independent variables, that is polylactic acid content, roller temperature and roller pressure on useful functional properties such as bursting strength, bending load, tensile stress relaxation, tensile creep, rate of absorption, absorption capacity, porosity, abrasion resistance, and surface friction. Considering the linear, quadratic, and two-way interactive effects of independent variables, the second-order polynomial has been suggested for each property which proves good association except for absorption capacity and abrasion resistance. The effect of independent parameters has been studied and optimized from contour diagrams. The optimized process parameters for 140 g/m2 fabric are polylactic acid content 30%, mesta content 70%, roller temperature 170°C, and roller pressure 150 N/cm2, which can be used successfully as a shopping bag. The shopping bag was prepared from developed fabric. Its performance test shows no deformation for up to 14 days in the hanging test, resistance up to 10 wetting-drying cycles proves reusability, it sustains up to four drops, and has a slight strength loss in 30 days of atmospheric exposure.