A New Strategy for Enhancing the Alkali Deweighting Efficiency of Polyester Fabrics Based on Non-Aqueous Media Systems

Abstract

In this study, a non-aqueous media system was employed to systematically investigate the impacts of alkali concentration, moisture content, and recycling times on the deweighting rate, dyeing properties, and physical characteristics of polyester. The research incorporated a comprehensive suite of analytical techniques. These included whiteness test, gross efficiency analysis, gas chromatography-mass spectrometry (GC–MS), thermogravimetric analysis (TG), and K/S value. Additionally, the color fastness to washing and rubbing was evaluated. And the hydrophilic properties, microstructure features, thermal stability behavior, and dyeing properties of the treated fabrics were thoroughly examined. The findings revealed that only 7 g/L NaOH was needed in the non-aqueous media system to achieve a 25% of deweighting rate of polyester fabric, which is higher than that of 36 g/L in the traditional water bath system. The amount of alkali agent greatly decreased. Moreover, when the moisture content fluctuated within the range of 100–130%, the deweighting efficiency only varied by ± 6.5%, indicating remarkable process stability. After five recycling cycles, the media maintained a deweighting rate of 23–25%, highlighting its sustainable potential. Regarding fabric performance, polyester treated in the non-aqueous outperformed traditional counterparts in whiteness, hydrophilicity, thermal stability, and dyeing depth. This system reduced alkali consumption while enhancing both deweighting rate and dyeing performance. Crucially, effective deweighting capability persisted after five recycling cycles. These results clearly demonstrate that the non-aqueous media system exhibits superior efficiency and environmental friendliness compared to traditional methods. This innovative research can effectively reduce the usage of chemicals, lower environmental pollution, and is conducive to promoting the sustainable development of the printing and dyeing industry.