Spray Agglomeration

In order for fine powders to unfold their full performance, they must often increase their size and be brought into shape first. This is done by spray agglomeration. Especially dusty, sticky and lumpy powders are suitable for transformation into free-flowing agglomerates in the fluidized bed. At the same time, the agglomerated particles are well soluble and redispersible and can be pressed optimally thanks to their porous surface. This simplifies dosing and further processing. Different properties of various bulk materials can be influenced in this way: Handling of detergents becomes dust-free, powders can be compacted more easily, instant powders and granulates dissolve uniformly without forming lumps.

The spray agglomeration transforms dusty, lumpy powders into free-flowing, easily dosable agglomerates. In the agglomeration, fine powdery particles are moved in the fluidized bed and sprayed with water or another liquid binding agent, the so-called adhesive. Liquid bridges are formed which bond the particles and form up to 3 mm large agglomerates after drying. Spraying with the fluidized bed technology is continued until the agglomerates have reached the intended size. Which adhesive is used depends on the desired properties of the end product.

The binding agent dries or solidifies on the surface of the powder particles and sticks these together point by point – the result is a blackberry or raspberry structure of the agglomerates. In the fluidized bed the moisture evaporates quickly, the dissolved substances crystallize and harden during drying. Although the resulting agglomerates are usually less resistance to breakage than the original powder particles, their shape brings other advantages. Because of their large surface area, they are easier to wet and are more easily redissolvable in water or better processable in subsequent process steps (e.g. tablet forming).