linearextrude

Linearextrude is a term encountered in some German- and Dutch-language industrial texts to describe a linear extrusion process in which material is forced through a straight shaping die to form a continuous profile along a linear path. The name combines the German words for linear and extrusion and is often used, with regional variations, to denote a conventional, straight-line extrusion technique rather than processes involving curved or rotational tooling.

In practice, linearextrude involves feeding material—typically in a heated, plastic state—into an extrusion device such as a screw-type extruder or a ram, where it is pressurized and pushed through a fixed straight die. The extrudate is then drawn away by take-up equipment and directed through a cooling or solidification system to achieve the desired form and dimensions. The geometry produced is generally uniform along the length, making it suitable for long, straight profiles.

Materials commonly processed include thermoplastics such as polyethylene, polypropylene, and polyvinyl chloride, as well as certain metals in hot-extrusion applications. Typical equipment includes a feeding hopper, an extrusion barrel with a linear shear mechanism, a straight-through die, a cooling line, and winding or cutting apparatus for continuous or discrete lengths.

Applications focus on producing straight profiles like rails, channels, tubes, or filaments where constant cross-section is required. Advantages of linearextrude include high production rates and straightforward die design, while limitations include restriction to constant cross-section parts and sensitivity to material viscosity and cooling conditions.

See also: extrusion, extrusion die, profile extrusion, polyolefins.