Lamberti: Specific Technologies for Suspensions

Among the current crop nutrition and protection products available for agriculture, suspension-based formulations represent a very important segment for the market, which has steadily grown year by year. This is due to the fact that these products, compared to other forms of delivery, presents some major advantages for the farmer, such as ease of use and dose combined to a reduced environmental impact thanks to the fact that they’re water-based. Moreover, from a formulator perspective, the palette of chemical auxiliaries that the market can offer to formulate such products is well established and very rich, making these products easily adaptable to specific requirements.

However, there are still some SC specific instances that are difficult to handle even for skilled formulators: due to increasing pest and disease resistance in the field to single-active based SCs, the crop protection products market is moving towards a wide offering of multiple active suspensions, which are not always easy to make. In addition, the request for more concentrated and effective formulation is pushing the limits of the formulation space that are currently accessible with standard surfactants.

For these reasons, Lamberti has developed a specific range of product to handle these difficult situations while giving formulators good flexibility in formulating their products. Within this range, a new class of so-called “superdispersing agents” was created, specifically designed to perform even in the most difficult instances. One example of such product is Envi-Pol® 871, a polymeric superdispersing agent proven very effective for SC formulations.

By including this particular molecule in the recipe, viscosity during milling phase is kept well under control, making it possible to reach high load suspension concentrates like Metribuzin 650 g/l, which is normally very challenging to produce with standard surfactants like TSP derivatives. Moreover, thanks to its polymeric nature, Envi-Pol® 871 can also help to prevent crystal growth issues: this feature is very useful especially when formulating with relatively soluble active ingredients (as shown in figure 1).


 

Another relevant benefit of this class of superdispersing agents is that their chemical structure allows an easier handling of multiple active SC formulations. In fact there are many examples where a combination of actives might be hard to process in just one milling operation, due to difference in active hardness, log pow or melting point, like the case of Metamitron, Metazachlor and Napropamide combination. In these cases, the use of Envi-Pol® 871 can result in a great compatibilisation effect, making it possible to mix and mill these actives in just one step without compromising final storage stability, blooming or suspensibility.

The usage of Envi-Pol® 871 has also been proven very effective for another particular class of crop protection suspension formulations: Flowable Seed Treatments. These type of formulations have an overall architecture that is similar to standard SCs, however there’s a great difference between them: for a flowable formulation, performance is not only given by the active ingredient selection and/or combination, but also from an important selection of the various coformulants that make the FS so peculiar (like pigment, stickers and antifriction agents). FS formulations have to perform well even before the seed is sowed, both in terms of granting good storage stability when applied onto seeds as well as minimizing any potential dust-off issue caused by the mechanical stress that seeds receive during the handling and sowing process. For this reason, having the possibility to increase coformulants level in an FS is indeed a winning strategy, but unfortunately this is condition is not always an easy to achieve, especially in high load formulations like Thiamethoxam 600 g/l or Imidacloprid 600 g/l. This is because in order to increase the level of coformulants, thus improving some side properties (e.g. dust-off, as shown in figure 2), the formulator could squeeze a greater amount of water out of the product that could ultimately result in a non-processable mix in the mill. By using Envi-Pol® 871, it is possible to overcome this issue and obtain a very low water content milling premix that can grant a lot more space available: this allows the introduction of further sticker or pigments that can increase FS performance not only on the field, but also onto the seeds right from the start. Similar to standard SCs, even FS Envi-Pol® 871 can facilitate the co-existence of more than one active in the same formula, thus giving the flexibility of choosing from a greater palette of crop protection molecule for specific and tailored end uses. 

 

Regarding nutrition products formulated as suspensions, Lamberti has applied all its available technical knowledge acquired with extensive work in crop protection SCs to solve production, stability and compatibility issues that can currently affect these type of formulations. In particular, it is well known that SC fertilizer with micronutrients can be difficult to stabilize for proper storage (milling, crystal growth and cracking issues), so a specifically designed product for this purpose has been engineered: Envi-Pol® 3010. This product is an acrylic based polymeric surfactant that can provide superior performances in super-saturated suspensions: thanks to its structure, it allows a smooth and fluid process for SC fertilizers that require milling, it considerably increases the storage stability of such formulations, it helps to prevent settling of the solid upon time and it allows a more effective crystal growth control for the formulation. In addition to that, Envi-Pol® 3010 is a polymer with high tolerance to extreme conditions of ionic strength and temperature, and therefore it can improve tank mix compatibility of SC nutrition products when combined with crop protection products like EC or SC.

In conclusion, thanks to the wide technological knowledge available within the company, Lamberti’s portfolio for the broad SC-type formulations has grown considerably in the last few years, in order to solve real and relevant formulation issues as well as provide maximum flexibility for the customer and the best value for the farmer.


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