extrusionbased

Extrusion-based refers to manufacturing and fabrication methods that shape material by forcing it through a die or nozzle to create a continuous cross section or to deposit material in a programmed path. Traditional extrusion produces long parts with a constant cross section, such as profiles, tubes, or sheets. In extrusion-based additive manufacturing, material is deposited layer by layer to build parts, enabling complex geometries without molds or tooling.

The core of extrusion-based processes is an extrusion system, typically consisting of a hopper or feed unit, a heated or cooled barrel, a screw or piston to move the material, and a die or nozzle that defines the final cross section. In hot extrusion, the material is plasticized before or during passage through the die; in cold extrusion, forming occurs near room temperature. Direct extrusion pushes material through a die with the ram on the same side; indirect extrusion uses a die on the opposite side to reduce friction. Hydrostatic and other specialized variants exist for certain materials and applications.

Materials used span plastics and polymers, metals (such as aluminum and copper), ceramics, composites, and pastes or food products. Common applications include profiles for construction, pipes and tubes, sheets, coatings, and continuous coatings. In extrusion-based additive manufacturing, thermoplastic filaments, ceramics pastes, or cementitious pastes are extruded to build parts layer by layer.

Advantages include high throughput, material efficiency, and the ability to produce continuous profiles or complex geometries. Limitations involve die design complexity, equipment cost, potential anisotropy in printed parts, and material-specific processing constraints. See also extrusion and additive manufacturing.