Pultrusion is a moulding technique used for manufacturing fibre-reinforced plastic (FRP) profiles. The process is similar to extrusion but with pultrusion, the plastic product is drawn through the extrusion nozzle in continuous tracks – unlike extrusion, where the product is pushed through. This ensures an excellent, specific tensile strength in the profile.

Five good arguments
FRP profiles can be pultruded with many different plastic materials and fibre types. They have five outstanding traits in common:

1. High strength/low weight. The weight of a FRP profile is only 20-25% that of a corresponding profile of steel, and 70% of one in aluminium. But the specific tensile strength of FRP is higher than that for either steel or aluminium. Thus, pultruded profiles in FRP can be used as construction members in houses, bridges, platforms and walkways.
   
2. Thermal insulating. FRP profiles have low thermal conductivity, and are used as cold-barrier profiles in windows, reefer lorries, cold storage and thresholds. The thermal coefficient of expansion is somewhat less than for steel, and is essentially lower than for aluminium. The mechanical properties are excellent even at very low temperatures.
   
3. Electrical insulating. The profiles are electrically non-conductive, and are transparent to RF-waves, microwaves and other electromagnetic frequencies. Thus, FRP is used as distance profiles in transformers, covers for third rails in subways, bus bars in high-voltage equipment, in GMS-antennas, cable trays and ladders for electricians.
   
4. Corrosion-resistant. Pultruded profiles don't rot. They remain unaffected by most acids, bases and other corrosive agents. These facts make FRP a natural choice in external and internal construction in pulp and paper plants, chemical plants, systems for water and wastewater, and construction close to salt water and other aggressive environments.
   
5. Designer-friendly. Pultruded FRP profiles can be pigmented or coated in high-quality finishes that enhance the appearance of many applications.  

Primo can supply a wide range of standard and custom-made FRP pultruded profiles for applications that require the properties described above.