The premixes are generated through the mixing of powder ingredients.
They are important for two fundamental reasons:
- They guarantee the possibility of entrusting production to third parties without having to reveal the recipe, the know how remains internal to the company, encrypting and protecting the name and usage percentages of individual ingredients;
- They allow optimization of the production process, favoring solubilization, through the use of already mixed powders.
The production of premixes is not at all simple, because it is based on the mixing of solids (powders); overall, theoretical knowledge about solids mixing is less advanced than that about liquid mixing, and solids blending is a less known and more complex phenomenon.
The result of a mixing process depends on several factors:
- variables related to the substances to be mixed such as powder density, particle shape, moisture, friability, flowability;
- characteristics of the mixer used, namely type of mixer, size, shape and construction features;
- mixing conditions, which refer to the order of substance addition, speed, agitation time and volume occupied by the powders.
The role of I.T.P. SRL
I.T.P. SRL, thanks to state-of-the-art laboratory equipment and instruments, is able to:
- completely characterize the powders of interest;
- optimize the mixing process;
- assist in choosing the mixer suitable for the process.
Let us analyze in detail the three points just listed, starting with powder characterization.
If particles of different sizes and densities are present in the mass to be mixed, a potential for demixing is introduced that tends to cause particle segregation. Spherical, smooth and rounded particles flow more easily than irregular and filamentous ones, therefore, they tend more easily toward segregation.
The moisture content of powders can influence mixing positively or negatively. Optimization of the mixing process occurs, instead, through the study of the process conditions themselves, verifying the order of substance addition, the speed and optimal agitation time to favor mixture homogeneity. If a mixture is segregable, the phenomenon is accentuated during processing phases, which involve exposure to vibrations, and during storage.
Finally, every mixture can be made homogeneous if the suitable mixer is chosen in terms of size, shape and construction characteristics.
