What is Pultrusion

As part of our continual commitment to find the best ways to make use of composite materials, in our last blog we looked at the benefits of them when used in a variety of infrastructures. In this piece, we consider the pultrusion process and how it can be beneficial to your build.

What is pultrusion?


You might be interested to know that the word pultrusion derives from the words ‘pull’ and ‘extrusion’.  It’s a relatively new process that was originally introduced back in 1951 by W. Brandt Goldsworthy, a plastic pioneer who was renowned as a member of the Plastics Academy Hall of Fame.

Pultrusion is a manufacturing process that’s used to create continuous lengths of FRP or Fibre Reinforced Plastics. The process is used to deliver a product that benefits from constant cross-sections.

What is the pultrusion process?

The pultrusion process is a series of steps that results in converting liquid resin and reinforced fibres into a fibre-reinforced plastic. This is more commonly recognised as FRP.  Using an automated process, it pulls fibreglass rovings through a resin impregnator or resin bath.  In entirely saturating the reinforcements, it delivers an energy-efficient process of continual production of FRP structural components; ideal for a variety of projects.

From the result of the heated steel pultrusion, the resin becomes hard, which means that you end up with an equally lightweight and tough product that echoes the shape of the die.  You’ve got two main pulling systems to choose from: cat-track which is continuous, or hand-over-hand which is reciprocating.

Designed to suit your project

When it comes to the fibre reinforcement rovings, it’s essential that they’re carefully positioned by the creels; ensuring that your finished composite benefits from high quality and strength.

As for the resin impregnator, it’s vital that it entirely saturates the fibre reinforcements. This is either in a wet out or a resin bath, combined with a choice of polyurethane, epoxy, vinyl ester or polyester. You can also combine this with a variety of additives and fillers including fire inhibitors and colours; a great way of ensuring that the composite has a long shelf life.

The next stage of the process is where excess resin is removed; forming the fibre reinforcements into the desired shape. Additives like protective surface veils and continuous strand materials can also be included; further enhancing the composite life and improving its resistance to corrosion.

Following this, the polymerisation process is where the fibre passes through steel die; being cured and heated to create a solidified polymer. Once this is complete, the FRP is sufficiently hardened to ensure that the saw can cut the material to the optimum length for your project. Using urethane pull locks means that there’s no possibility of the cured profiles being deformed or cracked.

What is pultrusion used for?

As we’ve seen through the process, pultrusion creates extremely tough and long-lasting components, which means that it’s ideally suited for corrosive and demanding environments. In addition, the material is rot-proof and rust-proof. You’ll find that the lightweight FRP is also non-conductive; making it suitable for a vast variety of building projects.

What are the benefits of pultrusion?

Certainly, in recent times, there’s been a considerable demand for pultruded composite profiles. Thanks to a much more energy-efficient way of creating components, the pultrusion process is as cost-effective as it is in its actual efficiency. With limited error possibility and the ultimate in convenience, you’ll find that your build will benefit from a guaranteed advantage.

The pultrusion process is an ideal solution for an extensive range of industry sectors. In construction, it’s great if you’re looking to produce glass-fibre reinforcement or profile carcasses. As for the aerospace industry, pultrusion is recognised as a highly beneficial way to manufacture aircraft components. Within the chemical and agricultural industries, pultrusion makes for an excellent choice for chemical plants and livestock facilities. Another industry sector that will benefit from pultrusion is the automotive sector; particularly where extremely tough materials are required to create complex vehicle parts.

There are many other industry sectors that can also benefit from pultrusion, thanks to its high-strength capability, combined with its ability to meet chemical stability.


Plura – your choice for pultrusion

At Plura, we recognise how essential it is to use the best processes in order to create your chosen build project. And our pultrusion capabilities mean that we can meet your individual needs; always ensuring that every component is carefully designed and built to the highest of standards. Our constant commitment to discovering the best ways to find alternatives to traditional materials such as wood or steel with composites that are manufactured in the UK that are super lightweight, and designed to the exact shape or size that you need for your structural design is our end goal.

Discuss your next project with us