Optimum vacuum solutions from a single source for your drying process
In the morning with coffee and cereal or getting vaccinated
before the vacation – almost all of us have experienced
lyophilized products. But what's behind the process of freeze
drying and why does vacuum play a decisive role?
What is freeze drying?
Freeze drying, also called lyophilization, is a particularly gentle drying process and is, therefore, suitable for sensitive products. The material to be dried is initially frozen, and then dried in a vacuum chamber. In contrast to conventional vacuum drying, the primary drying takes place by sublimation. This requires a much deeper vacuum. The water or solvent is transitioned directly from the solid to the gaseous state. Meanwhile, the heat necessary for the phase change is provided, for example, via heating plates. Followed by optional secondary drying to further reduce the residual moisture content of the product. This is done by desorption of bound moisture. A low pressure and an increased heat supply promote the subsequent drying. The vapor is frozen by a cold desublimation trap, often called a condenser.