Sprasowanie

Sprasowanie is a forming process in which powdery or granular materials are compressed in a die to form a solid, cohesive body known as a green compact. The term comes from the Polish verb sprasować, meaning to press together. It is widely used in materials engineering, ceramics, metallurgy, and pharmaceutical tablet production. During sprasowanie, particles rearrange, deform, and may bond under applied pressure, sometimes assisted by lubricants or binders.

Common techniques include uniaxial pressing, where force is applied along a single axis using hydraulic or mechanical presses; isostatic pressing, which applies pressure from all directions through a fluid medium for uniform density; and hot pressing, where pressing occurs at elevated temperature to promote densification. Isostatic pressing is favored for complex shapes, while hot pressing is used for dense ceramics and metals. In many workflows, a green compact is formed before further processing such as debinding and sintering to reach final properties.

Applications span pharmaceutical tablets, ceramic and ceramic–metal components, metal powder parts, and briquettes or pellets for energy, catalysts, or filtration. Key parameters include compacting pressure, powder characteristics (flowability, blend quality), die design and fill depth, lubrication or binder systems, and pressing time; temperature and atmosphere matter in hot pressing. Advantages of sprasowanie include high production rates, good dimensional control, and suitability for large-scale manufacturing; limitations involve sensitivity to material flow, potential density gradients or defects, and the need for subsequent processing steps to achieve desired material properties.