Definition - What does Pultrusion mean?
This is a systematic manufacturing process that involves continuous molding and the reinforcement of polymers to form high-strength structural parts of continuous length and similar composite profiles: fiber reinforced polymer (FRP). The name was developed from the merging of “pulling” and “extrusion”—key processes.
It is used in the making of custom and standard structural beams, panels, rods, poles, gratings, decking, cross arms and other fiberglass structures; basically for application with uniaxial stresses.
Corrosionpedia explains Pultrusion
It is a process that consists of a combination of forming process and heat treatments to produce parts with uniform cross-sections and similar lengths.
This process involves the pulling of polymers like resin and fibers through dies and machines. The raw materials include a resin mixture of fillers and additives and flexible fibers. The raw materials are also in continuous forms-roving.
The polymers (reinforcements) are pulled by a pulling system through the resin bath (impregnation system) and performers (series of dies). The geometry of the finished part is regulated by a cut-off saw. The curing process is available inside the die after forming the polymers and is provided by zones of temperature heating. The die determines the shape of the profile, while the heat treatments and forces used determine the properties of the finished parts.
The performer involves the rearranging the fibers in the required shape and controlling the amount of resin used. The structure and surface finish is improved by the addition of surface veils and strand mats before it is passed through a heated steel die.