Pressing

Pressing is a manufacturing and preparation process in which material is subjected to applied pressure to shape, compact, or bond it into a desired form. It covers cold forming of powders as well as hot or warm densification, and is used in metalworking, ceramics, pharmaceuticals, food processing, and electronics manufacturing. The core idea is to achieve a specific geometry and density by compressing a blank or powder in a die or through a shaping tool.

Common methods include mechanical pressing, where a punch compresses material in a die; hydraulic pressing, which uses fluid pressure to apply large forces; and isostatic pressing, where uniform pressure is applied from all directions, often in a fluid medium. Hot pressing or warm pressing adds heat to promote bonding or densification. Materials commonly processed by pressing include metal powders, ceramic powders, and composite blends, frequently followed by sintering or bonding steps.

Applications are wide. In powder metallurgy, pressing forms compacted billets that are later sintered to full strength. In pharmaceuticals, tablet pressing compacts active ingredients with binders into tablets. In ceramics and electronics, pressing shapes green bodies before sintering. In food processing, presses extract juice or oil from fruits, vegetables, or olives. In record production, vinyl pressing uses heated material and stamping to form records with grooves.

Key considerations include achieving uniform density and minimal porosity, controlling grain structure in thermally treated metals, tool wear, lubrication, and scaling from laboratory to production. Safety, energy efficiency, and process control (monitoring pressure, temperature, and dwell time) are important for consistent quality in pressed parts.