News

What is Pultrusion? (Video Series)

Jun
9

Pultrusion is the process used to form fiberglass-reinforced polymer – or FRP – into a strong but lightweight profile. This process creates continuous lengths of FRP with a consistent cross-section.

The possibilities for custom shapes are virtually endless. For example, Bedford PROForms structural shapes like these are made of pultruded FRP.

The pultrusion process starts by pulling in a combination of fiberglass reinforcements. Creels of fiberglass roving provide the strength along the length of the profile. Rolls of continuous filament mat provide the strength across the width of the profile.

These reinforcements are fed through preforming guides that begin to shape the raw glass fibers into the finished profile. The glass is then pulled into a resin bath that saturates the reinforcements. The resin bath contains a mixture of resin, most commonly polyester or vinylester, pigments to add color, filler to enhance properties, and a catalyst to aid in curing, or to turn it from a liquid into a solid. Surfacing veil may also be added to give the profile a resin-rich surface and enhance the appearance of the finished product.

The materials are then pulled through the heated pultrusion die. The heat causes the resin to cure or harden to create a solid, rigid profile in the exact shape of the die. The cured profile is then advanced by a caterpillar-style puller to a cut-off saw, where it will be cut to its final length.

The finished product is now put into inventory at one of our warehouses, sent to our state-of-the-art fabrication center for additional processing, or crated for shipment to the customer.

And it all happens right here in the USA, where Bedford’s pultruded profiles are proudly made by American workers.