关键词: 蔬菜 农药残留 特点 控制, 蔬菜 农药残留 特点 控制

Abstract:

The pseudo-ternary phase diagram of supercritical CO2- acrylic acid resin- dimethylbenzene was determined. The influence of nozzle’s structure on the effect of acrylic acid varnish spraying atomization including supercritical CO2 was investigated. The influences of temperature, pressure and CO2 content on the magnitude of atomization particles and spraying angle were investigated by using L9(34) orthogonal experiments．The result indicated that when spraying operation satisfied these conditions(the temperature is less than 90℃,the pressure is larger than 8Mpa,and the CO2 content is not more than 35%,the above pseudo-ternary system is in stable monophase field.The favorable spraying effect is gained using nozzle with diameter of 0.4mm and length less than 1mm, and the diameter of atomization particles obtained is 80μm. The higher index of temperature,pressure and CO2 content, the smaller magnitude of atomization particles, the larger spraying angle and the better effect of atomization. The optimization condition was 20Mpa, 80℃, CO2 35%, coating film samples attained achieved the national standard under the optimization condition (20Mpa, 80℃, CO2 35%).