Innovators push pultrusion processes and materials to new limits.

Highly customizable and incredibly durable, pultruded materials are finding growing demand in a tremendous range of applications. Market research firm Markets & Markets projects that the global pultrusion market will see a compounded annual growth rate of 4% from 2019 through 2024, reaching an estimated $3.4 billion.

The pultrusion process originated in the early 1950s to manufacture FRP composite profiles with a constant cross section. More than 70 years later, fabricators and material suppliers are exploring ways to shake up the process. Industry leaders will gather virtually for ACMA’s Pultrusion Conference April 13 – 15 to share the latest breakthroughs. In anticipation of the conference, Composites Manufacturing magazine provides a look at a few advancements in pultruded applications, manufacturing and materials.

Application Spotlight: Wind Turbines

One of the chief benefits of pultruded materials are the strength they bring to long spans. It’s one reason pultruded materials have become what Sascha Erbslöh, formerly with MHI Vestas Offshore Wind (MVOW), calls “the material of choice” for the structural building blocks of wind turbines, most notably the spar caps that serve as the skeleton of the rotor blade. (Last fall, Vestas agreed to acquire MHI’s shares in their offshore wind joint venture and has integrated MVOW into the Vestas group.)

Erbslöh says pultruded CFRP spar caps are inherently more efficient than those fabricated through earlier open-mold, wet lay-up processes. “The main advantage is, of course, that all the fibers are in the right direction,” he says. “[With an open-mold process] you can, in theory, put in individual unidirectional fiber layers, but if you infuse all that you always have a significant chance of creating wrinkles. That is almost completely eliminated if you use pultrusion.”

Erbslöh projects that this ongoing shift toward pultruded parts will drive significantly increased demand for technologies to support pultrusion as the wind energy market itself sees continued growth. The U.S. Department of Energy (DOE) projects that the United States will experience an increase from 113.43 gigawatts (GW) of wind energy in 2020 to 224.07 GW by 2030 and 404.25 GW by 2050.

That type of growth demands another critical characteristic: rapid manufacturing repeatability. That’s another clear advantage of pultrusion, Erbslöh says. “You can assemble it in a very controlled way with pre-manufactured parts. For the most critical parts, that is very advantageous.”

Speed in bringing turbines to market makes manufacturers more competitive and will further reduce energy costs which, in turn, will make turbine installations more attractive. The DOE notes in its 2019 Wind Technologies Market Report that the combination of more – and more efficiently performing – wind turbines is driving down wind energy costs to all-time lows of below two cents per kilowatt hour.