Fair-Rite offers ferrite components in various shapes in sizes, but all start out as a powder. In order to create the different geometries for its diverse applications, this powder is compressed under tons of pressure. While there are several major methods of doing this, the most popular is called dry pressing. Another method that Fair-Rite also uses is called injection molding.
The method of dry pressing is the most common way to form ferromagnetic powder into meaningful shapes. To do this, the powder must be mixed with binder and lubricants before being compacted. A press tool set typically consists of an upper and lower punch held within a die. The movement of these punches, along with the die, is done in a specific sequence such that the density of the formed part is uniform. Uniform density is important to ensure consistent electrical and physical properties throughout the part. The size of the press required, meaning the amount of tonnage required for a particular part, is dependent on the size of the part.
This process compacts powder only along one axis. Therefore, parts having details not along the axis of compaction cannot be manufactured solely utilizing the dry pressing process – instead, additional machining steps would be necessary or a different forming process is needed.
Tool design is a critical aspect of dry pressing. At Fair-Rite, this design is performed by our in-house experts who have extensive experience. As part of the process, we will work with our customer to utilize our expertise and develop a tooled solution to meet your specification.
At Fair-Rite, we have the capabilities to produce components 250 cm2 by 18mm thick and 34 cm2 by 80 mm long. Call for custom capabilities to meet your design needs.
For relatively small parts with more intricate features that cannot be generated with traditional dry-compacting process, injection molding is used. In this process, the plasticized material is forced in to a mold to achieve the desired shape. These are for designs that have features not along the axis of compaction in dry-pressing.