Pultrusion is a continuous manufacturing process for fibre‑reinforced polymer profiles of constant cross‑section. Dry fibre rovings, mats, or fabrics are pulled through a resin impregnation bath and then through a heated steel die. Inside the die, the resin cures under controlled temperature and pressure, yielding a fully consolidated structural shape. Typical line speeds range from 0.2 m/min for thick, complex profiles to over 2 m/min for simple, thin sections.
The process is inherently suited to high‑volume production of linear elements such as I‑beams, channels, angles, tubes, and solid rods. The continuous pulling action ensures consistent fibre alignment and high fibre‑volume fractions (commonly 55–65%), which translates into excellent longitudinal mechanical properties. Because the die determines the final geometry, pultruded parts require minimal secondary finishing.
For a formal definition and the process limits, refer to:
Material property data relevant to pultruded products can be found on:
- FRP Composite Material Characteristics – Includes pultruded laminate values
- GFRP Material Data – Specific data for glass‑based pultrusions
The Wikipedia entry on pultrusion provides a neutral summary of the process history, variants, and applications.