Feb 15, 2023
Ingevity solutions for challenging water dispersible granular formulations
INGEVITY IN THE NEWS
Introduction on Water Dispersible Granules (WDGs)
Water dispersible granules (WDGs) also known as dry flowable in North America, have been available since the 1980s. However, since the 1990s they have been developed on a significant scale as safer and commercially attractive alternatives to wettable powder and suspension concentrates globally. Water dispersible granules are non-dusty, free-flowing granules, which should disperse or dissolve quickly when added to water in the spray tank. As there are no spillage hazards, and with safer disposal of packaging, they are regarded as more attractive, convenient, and environmentally friendly products than EC (Emulsifiable Concentrate), S (Solutions), Dusts, Pellets, and WP (Wettable Powders) formulations.
Dispersible granules are obtained by blending and agglomerating a ground solid active ingredient together with surfactants/binders and other formulation ingredients. After granulation, drying step is necessary to reduce moisture to the acceptable and required limit. The shape, size and performance of the granules vary according to the manufacturing process used to produce them.
Extruded WDG is one of the rapidly growing formulation types that provides quicker dissolution while maintaining pallet integrity. These formulations have a high loading of active ingredients, which reduces transportation costs.
However, with the need of extra-high loading active and multi-active loading WDG, there are plenty of challenges that formulators are facing currently.
- Suspensibility and disintegration
- Long shelf life
- Formulating a granule that will extrude well and disperse well
- Cold water breakup
Among those mentioned above, the most frequently occurring problem in achieving desired performance is the high-suspension stability, so called suspensibility, with rapid granular disintegration. As most active ingredients are hydrophobic compounds, they often require low solubility dispersants to provide high suspensibility; while high water solubility dispersant is desired to provide quick disintegration. These two properties are diametrically opposed, making the selection of a dispersant difficult… Read full article