How FRP Is Made

THE PULTRUSION PROCESS
Most Bedford fiberglass shapes are manufactured using the pultrusion process. Just as it sounds, the machine grips the raw materials and “pulls” them through a series of steps until the finished profile reaches the cut-off saw.

The pultrusion process is 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.

1Reinforcement

Reinforcement

The process typically starts by pulling in two forms of fiberglass reinforcement. Creels of fiberglass roving provide unidirectional strength along the length of the profile, and rolls of woven fiberglass mat provide multidirectional reinforcement. All reinforcements are fed through pre-forming guides that will begin to shape the raw glass fibers into the finished profile.

2Wet-Out

Wet-Out

The fiberglass reinforcements are pulled through a bath of thermoset resin — typically polyester or vinylester — as well as pigments to add color, filler to enhance properties, and a catalyst to aid in curing. Resin also provides an additional form of reinforcement.

3Surface Veil

Surface Veil

Just before all the material is pulled into the heated die, surface veil is added to enhance the surface appearance of the final product.

4Curing

Curing

Wet-out reinforcements are pulled through the heated pultrusion die, which begins the thermosetting process that causes the resin to “cure” or harden. By the time the part exits the die, a solid, rigid profile in the exact shape of the die cavity has been formed with all the reinforcements laminated inside.

5Cutting

Cutting

The finished product is then pulled to the cut-off saw and cut to the desired length. After cutting, it is placed in stock at one of our warehouses, sent to our state-of-the-art fabrication center for secondary processing, or crated for shipment to the customer.