Solid pesticides granules

Solid Active Ingredients - Some pesticide applications require a particular physical form, generally to conform with application equipment available to the grower. Granules, for example, are commonly used as the means to apply insecticides to com. A solid active ingredient can be dissolved in a solvent and then absorbed by a carrier. This is, however, often not economical. The alternative used by the pesticide industry is to use a mineral as a substrate onto which the solid pesticide is adhered. High absorbency here is not required, and in fact can be detrimental. 

The main purpose of pesticide formulation is to manufacture a product that has optimum biological efficiency, is convenient to use, and minimizes environmental impacts. The active ingredients are mixed with solvents, adjuvants (boosters), and fillers as necessary to achieve the desired formulation. The types of formulations include wettable powders, soluble concentrates, emulsion concentrates, oil-in-water emulsions, suspension concentrates, suspoemulsions, water-dispersible granules, dry granules, and controlled release, in which the active ingredient is released into the environment from a polymeric carrier, binder, absorbent, or encapsulant at a slow and effective rate. The formulation steps may generate air emissions, liquid effluents, and solid wastes. 

Matrix Particles. Small particles based on a matrix can range in size from powders (microparticles) to granules (fine to macrogranules) to pellets (43). Microspheres can be considered as the matrix equivalent to microcapsules. Most controlled release granules are matrix-based, although some have a solid core or reservoir of pesticide (with a coating). 

If the pesticide constituent is a solid that is not soluble in oil or water, dien either a suspension concentrate (SC) or a water dispersible granule (WG, WDG) can be evaluated. A suspension concentrate is a dispersion of active ingredient in a continuous aqueous phase. The concentrated suspension is then diluted in the spray tank prior to application. If the solid has to be dispersed in an oil phase, then the oil flowable (OD) has to spontaneously enuilsify if it is to be diluted into an aqueous spray tank. 

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