Construction of aqueous ultrasonic cleaning system for replacing the solvent cleaning of clothing with aqueous system

用于衣物干洗的主要溶剂是过氯乙烯（PC）和碳氢化合物。PC已被列为可疑致癌物、有害空气污染物和臭氧消耗物。碳氢化合物在环境/安全方面的安装许可仍然存在不确定性。因此，尽管已有许多关于超声水清洗去除硬质基质土壤的研究，但对超声水清洗去除纺织品基质土壤的机理尚不清楚。为建立替代生态上不可接受的有机溶剂的水中超声波清洗系统，研究了超声波对纺织基材的去除机理。利用实验制作的超声波去除织物上土壤的效果评估装置，以28 kHz的声波，功率密度为1W cm^<-2>，作为声压，溶解氧浓度和表面活性剂十二烷基硫酸钠（SDS）或聚氧乙二醇单n-十二烷基醚（C_<12>E_n）浓度的函数。采用CI溶剂黄5作为模型有色油土，角鲨烯、硬脂酸胆固醇、三油酸和油酸作为模型皮脂土成分。土壤的去除效率随声压的增大而增大，且声压与去除效率之间呈正斜率的直线关系。在水中加入表面活性剂C_<12>E_n（临界胶束浓度C_<12>E_n），可获得较高的去除率（约90%）。结果表明，声场下超声清洗过程的主要机理是声压、空化、纤维与土壤的亲和作用以及表面活性剂的物理化学作用。

The prominent solvents used for dry-cleaning of clothing are perchloroethylene (PC) and hydrocarbons. PC has been declared a suspected carcinogen, hazardous air pollutant, and ozone depleter. Hydrocarbons have still an uncertaincy about installation allowances as regards environmental/safety aspects. Therefore, although there have been many studies on aqueous ultrasonic cleaning processes for removing soils from hard substrates, the soil removal mechanism from textile substrate by aqueous ultrasound is not well understood. The mechanism of soil removal by aqueous ultrasound for textile substrate was investigated for establishing the ultrasonic cleaning system in water as replacements for ecologically unacceptable organic solvents. The removal of soil on polyester or cellulose fabric substrate was examined by the use of the experimentally produced apparatus for evaluating the effectiveness of ultrasound in the soil removal from fabric, with sound waves of 28 kHz at a power density of 1W cm^<-2>, as a function of the sound pressure, dissolved oxygen concentration and the concentration of surfactant sodium lauryl sulfate (SDS) or polyoxy-ethyleneglycol mono n-dodecyl ether (C_<12>E_n). CI Solvent Yellow 5 was used for the model colored oily soil, and Squalene, stearic acid cholesterol, triolein and oleic acid were used as the model sebum soil constituents. The removal efficiency of the soil increased with increasing of sound pressure and the straight line with positive slope was also obtained between sound pressure and removal efficiency. The high effectiveness (about 90%) of oily soil removal from polyester was obtained with adding the surfactant C_<12>E_n to water (critical micelle concentration of C_<12>E_n). It has been shown that the main mechanisms responsible for the ultrasonic cleaning process in a sound field are sound pressure, cavitation, the affinity between fiber and soil, and the physic-chemical action of surfactant.