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As the active ingredient concentration increases, effective surfactant partitioning at the solid/water interface is critical to maintaining low viscosity. Formulation Tank Mix Compatibility : In general, SC tank mix very well with another SC or WP, and problematically with EC formulations. Aside from minimizing available void space between solid particles, the upper active ingredient concentration limit for technicals is related to the melting point of the technical and the heat generated during processing. Once the technical begins to be affected by the processing equipment (usually manifesting itself as a dramatic viscosity increase), the upper formulation concentration has been reached. Xanthan gums affect formulation viscosity as a function of temperature: as the temperature increases, viscosity decreases. This general purpose spray benefits from the formulation being stable on a variety of surfaces both porous and non-porous as well as being stable in the treated environment. This formulation type is given the code ZC globally and by the Australian regulator. Dry Processing: a high melting technical is passed through a hammermill and/or airmill until the desired particle size distribution is obtained; a dispersion is made of formula weights of water, surfactants, biocide, defoamer (where appropriate, salt is also added for density modification as well as "swelling" clay); the proportional weight of milled technical is added to the above dispersion and mixed until uniform; the proportional weight of xanthan gum/propylene glycol pre-slurry (where appropriate) is added to the dispersed technical slurry under agitation and mixed until uniform; Depending on the solvent, they can emit a harsh smell. In order to understand product physical limitations, it is necessary to evaluate the formulation performance under both static and dynamic storage conditions. As the temperature increases, formulation requirement shifts from high propylene oxide (to ethylene oxide ratio) to high ethylene oxide (to propylene oxide ratio) surfactant composition. These methods could include, but not be limited to, formulation viscosity and physical suspension (dispersion) upon dilution. Formulation, Emulsifiable Concentrate The mark of a quality SC is how highly refined the product milling is compared to other SC formulations, which ensures improved product coverage and retention of the product. In addition, with some technicals, the bacteria may actually be found to chemically degrade the active ingredient. Interestingly, even within the ethylene oxide/propylene oxide block copolymer class of surfactants, as the active ingredient concentration increases, the selection of surfactant becomes highly specific to the temperature at which the formulation is processed (or stored long term). This bleedlayer formation may be indicative of either sediment formation or non-uniform distribution of active ingredient throughout the slurry. Those formulation which demonstrate increased viscosity and/or poor physical suspension in various water hardnesses are rejected. Unlike Wettable Powder processing, where a clay or silica milling aid can be included in the formulation to minimize the effect of heat upon the technical surface, dry technical processing for Suspension Concentrate will have significant impact upon formulation performance. Suspension Concentrate Development : The basic Suspension Concentrate formulation contains the following components: * Required only where hydroxycellulose viscosity modifiers are used. There are three factors that dictate the extent to which the milled technical has been stabilized at its primary particle size: The kinetics of surfactant equilibrium at the solid/liquid interface, Most mixing equipment will not return technical agglomerates to their primary particle size; deagglomeration is dependent upon the kinetics of the surfactant partitioning to the solid surface being relatively fast. The surfactant effect upon flowability relates to its efficiency to wet the solid technical into the water phase: the more efficient the surfactant, the lower the formulation viscosity (in the absence of viscosity modifier). When you add the granules to water in a spray tank, the solution quickly disperses to form a fine particle suspension in the liquid. Formulations can play a vital role in determining the performance and use pattern of a product. Alternatively, urea may be included as a formulation excipient to facilitate freeze/thaw stability. However, their water dispersibility is adversely affected by the presence of high electrolyte (fertilizer) solutions and may be a major culprit when compatibility issues are identified. At this moment of surface softening three interactions are possible: Two particles of technical reform a stable agglomerate, Surfactant, present at the technical surface, is permanently adsorbed into the technical. Polyhydroxycellulose thickeners are used at a relatively small %W/W concentration in the formulation. The formulation should, for example, demonstrate low viscosity (in the absence of viscosity modifier) over the temperature range of 1C to 50C. An SC usually comes with a wetting agent or surfactant that allows the active ingredient particles to ow easily in water. Consider the following: If the specific gravity of the water insoluble technical is 1.2 X 100 gm/mL, then a particle 1T3 in volume would weigh approximately 1.2 X 10-8 gm; If the molecular weight of the water insoluble technical is 250, then the 1T3 particle would consist of approximately 2.88 X 1013 molecules of which a fraction are at the surface; If you assume that the solid surface structure may not follow a consistent molecular pattern (due to processing and the presence of impurities, for instance), then the organic solid surface can be viewed as consisting of carbon, hydrogen, oxygen, nitrogen, etc.

Particle size reduction of Suspension Concentrates can be accomplished either wet or dry: In the real world, most formulations will experience cyclic temperature conditions: cold winter, moderate spring and fall, and hot summers. A ZC formulation is a stable suspension of fine particles of technical material (Suspension Concentrate), combined with a suspension of microcapsules of technical material (Capsule Suspension) in an aqueous phase together with suitable formulants. Its important to note that with this formulation type, constant agitation is recommended to ensure best suspension in the tank. Formulations should demonstrate low viscosity and physical suspension upon dilution in various water hardness after initial processing. thereby resulting in a dramatic and significant viscosity increase. Container Rinsing : Government agencies have become increasing rigorous in the enforcement of proper container clean-out prior to disposal. However, since nonionic surfactant partitioning (solubility) between aqueous and non-aqueous phases is affected by temperature, the optimum wetting surfactant at one temperature may not be the optimum wetting surfactant at another temperature. Aside from the aesthetic of the black bacteria colony formation and associated odor, there is a major concern that the viscosity building structure has been affected. Formulation concentration : dictates formulation composition. One example is the combination of CS and SC technologies, which is known as a ZC formulation. As the formulation active ingredient concentration increases, the quantity of nonionic surfactant required to wet the technical into water also increases. Surfactants :In terms aqueous formulation performance, surfactants can be divided into two classes: nonionic surfactants which serve to wet the organic technical into water and anionic surfactants which serve to uniformly disperse the organic technical into water; both as a concentrate and upon dilution. Quality ZC formulations stay stable on surfaces. First; water must contain approximately 15%W/W propylene glycol in order to suppress the freezing point of water 9 F; Therefore, the most efficient surfactants are those which wet the technical (measured as low viscosity) at high formulation concentrations over a wide temperature range and at low formulation weights. Therefore, upon extended storage (time), the technical may con- tinue to deagglomerate (kinetics of surfactant surface equilibrium) to the point that excessive surface has been exposed to accommodate the surfactant present. "Swelling" clays thicken by means of generating a structure within the water phase based upon surface charge. In addition to these concentrate formulations frequently used to create dilutions for treatments, there are also a range of formulations that exist for specific job types, including many baiting formulations. Nonionic surfactants, by their very chemical composition, function as a bridge between the two phases by partitioning between the aqueous and non-aqueous phases. From this evaluation it would be determined that ethylene oxide/propylene oxide block copolymers are the most effective (low viscosity) surfactants for high concentration Suspension Concentrates. Allowed to dry in the commercial container, the Suspension Concentrate will form a film which resists water penetration. 1. Xanthan gum, which generates increased viscosity through controlled incompatibility with the aqueous phase, will lose water solubility in the presence of water soluble salts. Sediment formation : is a function of four factors: inadequate viscosity modifier in the formulation, heat adversely affecting xantham gum hydration, cyclic temperature storage of a water soluble technical, heat adversely affecting surfactant partitioning at the technical surface/water interface. Since uniform distribution of active ingredient upon application begins with uniform distribution in the commercial container, any deterioration of packaged product quality may ultimately adversely affect application efficacy. Salts and "swelling" clays do not demonstrate to the same degree resistance to water penetration upon drying; Sediment Formation- With the small particle size characteristic of Suspen-sion Concentrates and inadequate viscosity modifier concentration, technical will settle out of suspension with minimum void space between particles. As with dry technical processing, the lower the technical melting point, the greater the impact of processing shear during wet milling. Lot to lot (and source to source) variability of technical performance is related to dif- ferences in technical surface characteristics: crystalline structure, particle size, surface area, surface imperfections, and surface contaminants. 3. As a result, the dependence upon surfactants to formulate a low viscosity Suspension Concentrate increases as the formulation concentration increases. The introduction of ions in the form of surfantants may neutralize the clay surface charge and thus cause the suspension system to collapse. The higher the technical concentration in the formulation, the greater the tendency of the milled technical to agglomerate. Formulation processing :Uncontrolled heat during processing is the death knell for any Suspension Concentrate formulation. Partitioning of the surfactant between the organic surface and aqueous phase dictates formulation viscosity. Also, a formulation, upon storage, will demonstrate variable viscosity as a function of temperature: as temperature increases, viscosity decreases. Water-dispersible Granule (WG): A formulation consisting of granules, to be applied after disintegration and dispersion in water. Therefore, the use of salt solution density modification is sometime supplemented by the use of traditional xantham gum thickeners at very low rates.

These surfactants serve to disperse the organic technical particles by means of surface charge. Surfactants, by their chemical composition, are single molecules that demonstrate varying degrees of solubility in both polar and non-polar solvents thereby acting as "bridges" between phases? Suspension Concentrate (SC): A stable suspension of active constituent(s) with water as the fluid, intended for dilution with water before use. More information on APVMA-recognised formulations can be found at on the APVMA website. Mike de Luca, Technical Manager, Syngenta ANZ, Termite Professional Magazine - Australia, Copyright 2020 BD Publications Pty Ltd ATF BDP Trust ABN. However, this may adversely affect physical suspension of the Suspension Concentrate upon dilution. The result of this close packing of water insoluble technical is to allow little room for water penetration and resuspension with agitation (shaking). wdg bispyribac sodium output annual formulation