The Pultrusion process is a very efficient way to manufacture fiber reinforced composite products. It allows Pultrusion manufacturer to produce continous lenghts of Fiber-Reinforced Polymer(FRP) profiled shapes.
The term “pultrusion” is actually a combination of two words : “Pull” and “Extrusion”.this makes sense when we realize that the Pultrusion process involves a machine pulling the fiberglass through a liquid resin and then pulling that combination of glass and resin through a heated die. Extrusion is the process of creating objects of a fixed cross-sectional profile through a pushing process.
First, the pultrusion process involves pulling or drawing fiberglass(in the form of continous roving filaments, or fiber bundles) through a liquid resin which saturates the glass reinforcement, which is why pultrusion results in a strong material.Resin types can be polyester, vinylester, polyurethane and epoxy. Here a surface veil may also be added to protect against erosion or “fiber bloom” and provide corrosion resistance and ultraviolent resistance.
Second, the combination of resin and fiberglass is then pulled through a special heated and shaped die(in a process called polymerization) using a continous pulling device.
Third, the mass of reinforcement material hardens to conforms to the shape of the die and is heat-set into a permanent and rigid structurally reinforced shape.
And finally, the resulting high-strength profile is then cut to length-ready for use when it leaves the pultrusion machine.