Pultrusion

Pultrusion is a "continuous" process (one of the few existing processing methods for composites), enabling the production of composite profiles.

A contraction of the verb "to pull" and extrusion, this process, which appeared after the Second World War, competes with (or even complements) technologies for aluminum extrusion, thermoplastic resin extrusion, metal shaping and wood shaping.

Although pultrusion only accounts for 2-3% of the global composites market, or 200-300,000 tonnes of processed material per year, it is certainly one of the most promising production technologies in terms of development.

Pultrusion offers the following specific features:

• virtually infinite combinations of reinforcement/matrix combinations, giving designers free rein to their imagination and giving finished products extremely varied properties;

• Reinforcement levels of up to 70% by mass, with well-controlled orientation, guaranteeing first-rate mechanical properties;

• the ability to easily create even complex geometries, at low cost thanks to the high degree of process automation;

• the low labor requirement for these processing operations.

In this dossier, we focus on the presentation of pultrusion technology, with all its variants, and on the main characteristics and expected performance of pultruded composites. The basics of pultruded profile design, as well as associated applications and markets, are covered in [AM 5 540] . Readers will find some economic data in [Doc. AM 3 730v2].