how to produce frp pultrusion profile

Pultrusion Equipment, FRP Machine

Glass fiber roving arrangement – dipping – preforming – extrusion molding and curing – pulling – cutting – finished products

Pultrusion is an environmentally friendly manufacturing option that produces far fewer pollutants than many alternatives. It is also cost-effective and efficient, giving it broad appeal. The pultrusion process can produce FRP profiles (FRP square tubes, FRP round tubes, FRP channels and other alternative steel products). The pultrusion manufacturing process includes the following four steps:

Feed the fiber reinforced material into the guide rail

The pultrusion process involves pulling fiber reinforcement through a heated die. These materials are usually continuous rolls of felt and filament (also called roving). The first step in the process is to feed these raw materials into guide rails. This must be done very carefully, as inaccuracies can have a negative impact on the final outline. A large number of fiber inputs come together to create the part. Tension within the rails shapes the material.

Resin impregnation

Once brought together in the guide, the reinforcing fibers are impregnated with resin. Traditionally, this is done by moving fibers through a polymer trough. The tank usually consists of resin, pigments, fillers and curing catalysts. In some cases, the resin is injected into a heated mold.

Heating the mold

After passing through the soaking bath, the reinforcing fibers pass through a heated mold. This is the step where the fibers begin to solidify into their final shape, as heat initiates the cross-linking process within the impregnated reinforcement. A key consideration in this step is temperature. Low temperatures can result in a weaker composite profile, while too high a temperature can cause the composite to crack.

Separate from the mold

Towards the end of the heating process, the temperature of the resin will become higher than the temperature of the mold. This begins the separation process. The manufacturer uses a tractor to pull the cured profile from the mold. After separation, the profiles can be cut to appropriate lengths and subjected to secondary processing if necessary.