presarea

Presarea is the act of applying pressure to a material to shape it or reduce its porosity, resulting in a denser solid form. In Romanian, presarea refers both to the general act of pressing and to the manufacturing operation of forming material by compaction. The term derives from the verb presa, meaning to press.

In industrial contexts, presarea is a forming process in which powders or granules are compacted into a desired shape using a press and dies. It is widely used in powder metallurgy, ceramic production, and the manufacturing of pharmaceutical tablets. The process often serves as a preparatory step before sintering in ceramics and metal powders, or as the final step for producing compact items such as tablets and pellets.

Common techniques include dry pressing, where powders are compacted at room temperature, and cold isostatic pressing, which applies uniform pressure from all directions. Hot pressing combines pressing with elevated temperature to enhance bonding. Other variants include warm pressing and uniaxial pressing, depending on material, geometry, and performance requirements.

Typical process steps involve preparing a homogeneous powder blend, optionally adding binders or lubricants, filling a die with the material, compacting to the desired density, ejecting the formed part, and, if required, proceeding to sintering or firing to impart additional strength and uniformity. Quality factors include density, uniformity, dimensional accuracy, and mechanical strength; challenges can include porosity, internal defects, or tooling wear.

See also: powder metallurgy, tablet production, compaction.