关键词: 超声波清洗, 锦氨织物, 除油助剂, 除油率

Abstract: Nylon/spandex fabrics are widely used in high-end swimwear, sports underwear, medical compression stockings and other textiles due to their excellent elasticity, comfort and abrasion resistance. The spandex fibers provide outstanding elastic recovery, while the nylon component contributes to durability and strength. However, because spandex fibers have a strong affinity for spinning oils, degreasing in spandex-blended fabrics has long been a considerable problem in the conventional washing process, which requires multiple soaking, scouring and rinsing steps and suffers from drawbacks such as lengthy processing, high water consumption and low efficiency, all of which contradict the principles of green and sustainable production. In response to the above problems, ultrasonic washing machines have gradually won the favor of printing and dyeing enterprises due to their remarkable advantages of water conservation, reduced energy consumption, high efficiency, environmental friendliness and gentle and non-destructive cleaning. Ultrasonic waves are longitudinal mechanical waves with frequencies above 20 kHz, characterized by high frequency, short wavelength and high energy density. Its working principle is based on the cavitation effect in the liquid: when ultrasonic waves propagate through a liquid medium, they induce the rapid formation, growth and instantaneous collapse of microscopic bubbles. This process releases high-pressure and high-temperature shockwaves, which effectively strip away dyes, oils and impurities from fiber surfaces. Simultaneously, directional micro-jets accelerate pollutant dispersion, enabling deep-level washing. However, in the actual production process, enterprises generally report that the cleaning efficiency of ultrasonic washing machines still falls short of traditional processes and their degreasing performance remains suboptimal, especially when handling fabrics with high spandex content or tightly woven structures. Based on the above, in order to improve the degreasing performance of ultrasonic technology for nylon/spandex fabrics, it is necessary to clarify the influence of ultrasonic process conditions on the degreasing performance of greige nylon/spandex fabrics. Therefore, this study employed oil removal rate as the evaluation index and conducted single-factor experiments to investigate the influence of ultrasonic power, treatment duration, temperature, bath ratio, pH value and water hardness on degreasing performance. Subsequently, response surface experiments were applied to analyze the interactive effects of various factors on degreasing performance. The study also examined the synergistic effect of degreasing auxiliaries with ultrasonic treatment. The results indicated that ultrasonic duration and bath ratio had insignificant impacts, whereas ultrasonic power, temperature, pH value and water hardness exhibited significant effects on oil removal rate. Degreasing auxiliaries were found to synergistically enhance the oil removal rate when combined with ultrasonic treatment. The optimal process conditions for degreasing and cleaning nylon/spandex fabrics were as follows: ultrasonic power of 200 W, temperature of 80 ℃, treatment duration of 1 min, a bath ratio of 1∶20, pH of 6.7, and auxiliary agent A was prepared using deionized water. Under these conditions, the achieved oil removal rate reached 64.5%. The research results provide valuable reference for optimizing ultrasonic degreasing processes for nylon/spandex fabrics and developing specialized ultrasonic chemical auxiliaries.

Key words: ultrasonic washing, nylon / spandex fabrics, degreasing auxiliaries, oil removal rate