Developing a Fast-dispersing Extruded Water-dispersible Granule

A research-based agrochemical producer came to us with an apparently simple challenge: developing an extruded granule that dispersed as fast as spray-dried water-dispersible granules (WGs).

Our team began by examining why traditional WG materials like China clay filler and surfactants failed to yield quick-dispersing extruded granules. Then we investigated replacing the traditional inert materials with alternatives. After studying and testing a number of substitutes, the team discovered the most suitable new filler and surfactant combination—one that resulted in an extruded granule with a rapid rate of dispersion, both initially and after storage.

In addition to rapid dispersion (2-3 inversions for complete dispersion instead of the usual 12-15), the resulting formulation also featured good processing characteristics, including: low water requirements for extrusion, nominal extrusion resistance, low dustiness and minimal quantities of over- and undersize granules after drying. Although the original application was for extruded dispersible granules with a concentration of 10% or less, the new formulation matrix proved successful in concentrations up to 30%, making it suitable for use in an expanded number of granule-based products.