Effect of adjuvant S240 on atomization of water dispersible granule and emulsion solution

In order to study effect liquid characteristic on nozzle atomization process, this article applied Particle Droplets Image Analysis, high speed camera, and Malvern particle sizer to carry out experiment which focused on how Don-q, Score and the concentration of Breakthru S240 affected spraying sheet and droplet spectrum with conventional fan nozzle ST110-03 and anti-drift nozzle IDK120-03. The concentration of Don-q, Score solution was 0.275 % and 0.1 % respectively and the concentration of Breakthru S240 added into Don-q and Score was 0, 0.01%, 0.03%, 0.05%, 0.07%, 0.1%. Whole images and Detail image of ST110-03 and IDK120-03 nozzles' spraying sheet were taken at 0.3 MPa to observe its structure and to analyze the influence of type of formulation and adjuvant concentration using high speed camera and PDIA respectively. And VMD was obtained from Malvern particle sizer. The results showed that: when spraying 0.275% Don-q solution without adjuvant, spraying sheets and VMD of ST110-03 had no significant change compared with water; For IDK120-03, the spraying sheet had slight increase and the VMD almost did not change. When spraying 0.1% Score solution without adjuvant, the spraying sheet decreased by 35.2%, 40.5% individually and the VMD increased by 13.5%, 28.9% separately for ST110-03, IDK120-03 nozzle. Meanwhile, the structure of atomization was significantly affected by formulation. For ST110-03 nozzle, the film region was significantly reduced; fragmentation in film region become seriously with increasing holes in spraying film, and the wave formation was disappeared with thinner rim. For IDK120-03 nozzle, the film region was also significantly reduced; fragmentation in film region also become seriously with increasing holes in spraying film, but the hole was smaller than that of water and 0.275% Don-q. Combined with the analysis of surface tension and viscosity, it was found that the surface tension was an important factor affecting length of spraying sheet, structure of film, the droplet size; with the reduce of surface tension, the length decreased and the VMD increased. For the increase of Breakthru S240 concentration, the length of spraying sheet firstly decreased and then increased. It had the minimum when the concentration of adjuvant was 0.01% and the spraying liquid was 0.1% Score; it had another minimum when the concentration of adjuvant was 0.03% for 0.275% Don-q. Meanwhile, the structure of atomization was affected by adjuvant concentration at different levels. For ST110-03, the perforation disintegration was gradually serious, the hole become bigger when spraying score with adjuvant, and there was still no wave formation even if the concentration of adjuvant was 0.1%; the fragmentation in film region become seriously with increasing holes in spraying film, wave formation gradually decreased when spraying don-q with adjuvant. For IDK120-03, the perforation disintegration was gradually serious, the hole become bigger when spraying score with adjuvant; the fragmentation in film region become seriously with increasing holes in spraying film when spraying don-q with adjuvant. Whereas the VMD firstly increased and then decreased, and the VMD had the maximum when adjuvant concentration is 0.03%. Therefore, it was concluded that the trend of droplet change and the difference of spraying sheet length had certain correlation, and the apparent rule was with the increase of spraying sheet, the VMD decreased; with the decrease of spraying sheet, the VMD increased. Coupled with the analysis of surface tension and viscosity, surface tension was gradually decreased, but the spraying fan did not decreased or increased gradually. Maybe other characteristic of liquid combined with surface tension together depended on spraying fan length and change of atomization region in complicated mixture. So it was deduced that surface tension was one of important factors effecting atomization.