Pultrusion is a manufacturing process when fiber reinforced composite products are produced with a constant cross-section in an effective way. The term pultusion comes from the two words: “pull” and “extrusion”.
Extrusion is the process of creating objects of a fixed cross-sectional profile through a pushing process. So in the course of pultrusion, reinforcement material goes through pulling and pushing stages.
The pultrusion technology allows manufacturers to produce unique basal fiber reinforced plastic products (profiles, rods, bars, tubes, angles), that combine features of wood, metal, and polymer: high durability, low thermal conductivity, resistance to hostile environment and extreme temperatures.
Manufacturing of the profile is done by means of special pultrusion machine. The basalt fibers or mat material are fed into the guide, where they are pulled through the basin with the liquid polymer resin impregnating the fiber reinforcement. Usually epoxy, polyester or vinylester resins are used.
The combination of resin and basalt fiber is pushed through a heated shaped die, at this stage the resin undergoes polymerization.
Then comes the stage of cooling: when the mass of reinforcement material hardens and a rigid profile, corresponding to the shape of the die, is formed.
Last of all, a rigid basalt fiber reinforced profile is cut to length at the cut-off saw.
Basal fiber reinforced plastic profiles can be used but not limited for manufacturing of
- window profiles;
- ventilation systems;
- reinforced concrete;
- noise screens;
- traffic signal poles;
- ladders and handrails;
- different types of building structures.
The fields of applications, where a combination of special basalt material features required, generate particular interest. For instance, mining equipment and marine structures demand materials both with high durability and chemical resistance. In other cases, a combination of high durability and good thermal insulating properties are also of high importance.