Dry pressing is used for the production of dimensionally accurate mass-produced items. Free-flowing granules are compacted in steel matrices that are profiled according to the part to be manufactured. The high costs for the tool (partly made of hard metal) are usually only justified for large series.
Dry pressing is the most economical process for large quantities and is suitable for simple to complicated geometries. Pressed indentations and bores should normally only be provided in the pressing direction.
Depending on the design of the dry press machine, components from tile to match head size can be produced. Small discs or plates can be pressed up to a thickness of approx. 0.8 to 1 mm. The tape casting process is more suitable for even thinner, flat components. Fine webs or similar in the component can still be produced if the pressed granulate used can properly fill the cavities in the pressing tool or if the tool design is possible.
As for moisture, there are two ways of pressing: dry pressing and wet pressing.
When dry pressed, the water content of the raw material is less than 7%. In addition to possible density differences (internal inhomogeneities, blowholes), the complex powder preparation and restrictions in the component geometry are further disadvantages. On the other hand, there are also advantages such as good reproducibility, high dimensional accuracy and an automatic process flow.
The alternative to dry pressing is wet pressing with a water content of over 12%. This type of shaping enables complicated geometries and a more even distribution of density. However, drying of the green compact is necessary. In addition, pellets made from moist, crushed granulate have less compression and are therefore less strong than dry pellets.
We would be happy to support you in realizing your parts with this process.