Dry Compaction at Alexanderwerk

Economic and time efficiency as well as resource conservation: a range of tasks, which has to be faced from the new generation of machines for the pharmaceutical, chemical and primary industry.

With the dry compaction we at Alexanderwerk want to realize the requests of our customers: The majority of the raw materials in the pharmceutical, chemical and primary industry are powdery solids. These physical properties are not usually suitable for the further processing and are particularly challenging.

With the production of granules with a defined grain size Alexanderwerk can meet the challenge. This process avoids the requiremnets for additional binders or liquids, which are necessary in the wet granulation process, and as a consequence of the wetting process a drying phase is also required. Since no wetting takes place in roller compaction the product is not subject to chemical reactions or high temperature drying. In addition, the benefit of reduced environmental impact is achieved by dry compaction. The compaction of the materials is realized by high mechanical pressing forces, which provide the production of a compressed ribbon.

The high quality of the final product is determined by the compaction process and is achieved in three consecutive steps:


Using a suitable feed-in system, the raw material (powder) is routed through a horizontal screw feeding section. This has the function to provide the product precisely dosed, constantly and accurately to the rollers.


The powder is compacted between two rollers to a homogenous solid flake, whose bulk density is significantly higher than the bulk density of the bulk material. The air, which is displaced during compaction, must be allowed to leave the process properly.



The flakes, which were produced through the compaction process, are granulated using a suitable single or multistage granulation system. In this way, granules are created to the defined granule size required.