« Pull » + « Extrusion » = Pultrusion
Pultrusion is a continuous process for the manufacturing of composite materials with constant cross-section. The term is a portmanteau word, combining “pull” and “extrusion“. The shape of the profiles can be simple (tube, flat bar, rod…) or more complex (customized profiles).
Pultrusion offers the following specificities:
- almost infinite combinations of reinforcing / matrix couplings giving free rein to the imagination of the designers and conferring on the finished products extremely varied properties
- very good resistance to chemical agents
- very good dielectric properties
- very good thermal insulator
- low thermal expansion
- stability of mechanical characteristics guaranted even on a large temperature variation
- easy to machine, drill and assemble.
Technical principles :
Pultrusion is a continuous process for the manufacture of profiles. Depending on the required strength, a variety of reinforcing materials (roving, mats, fabrics, complexes, non-woven fabrics) packed into rovings (1) which are reeled off guide plates (2), and then impregnated in a resin bath (3). Using hydraulic clamps or other take-off units, the reinforcing materials are then pulled through a forming and curing die (4). The crossing into the heated die (5) creates the polymerization process of the thermosetting resin and give the final geometry of the desired profile. The profile is then cut to length (6).
The pultrusion process is slower than the extrusion process.
Borflex uses fiber glass reinforcements.