The RECOTRANS project achieves its first demonstrators thanks to a new microwave-based manufacturing process and lightweight multi-materials designed to produce more sustainable vehicles.

What is Pultrusion and Why It’s Revolutionizing Profile Manufacturing

Pultrusion is an industrial manufacturing technique increasingly used in sectors that demand strong, durable, and lightweight materials. In essence, it’s a continuous process that creates reinforced profiles — most often using fiberglass — by pulling fibers through a heated mold.

But what exactly is pultrusion? Imagine a system where fibers such as glass or carbon are impregnated with resin and continuously drawn through a mold that shapes and solidifies them. This is how pultruded profiles are made — valued for their stability, strength, and adaptability.

How the Pultrusion Process Works

The pultrusion process is simpler than it seems, yet highly technical. It begins with continuous fibers fed from spools. These fibers pass through a liquid resin bath, usually polyester or epoxy, which coats them completely.

Once impregnated, the fibers enter a heated mold that defines the final profile shape. The resin hardens with the heat, and the finished product is continuously pulled out and cut to the required length. Controlling temperature, speed, and pulling force is key to maintaining precise tolerances and consistent quality.

This process allows for the production of everything from thin rods to complex structural profiles — all with exceptional mechanical strength.

Advantages That Make Pultruded Profiles Stand Out

Compared to traditional materials such as steel, aluminum, or even wood, pultruded profiles offer clear advantages:

• Much lighter while maintaining stiffness and strength.

• Corrosion- and rust-resistant, ideal for harsh environments.

• Non-conductive, making them safe for electrical applications.

• Low maintenance and long-lasting.

• Dimensionally stable, even under extreme weather conditions.

Thanks to these properties, pultruded profiles are widely used in outdoor structures exposed to sunlight, humidity, or chemicals — environments where other materials would fail.

Fiberglass Pultrusion: The Perfect Balance of Strength and Cost

When we talk about pultrusion, fiberglass is the most common reinforcement choice. Why? Because it offers the ideal balance between performance and cost. It’s strong, affordable, non-conductive, and suitable for a wide range of applications.

In sectors such as construction, agriculture, chemical industry, and marine engineering, fiberglass profiles have become a standard solution. Common uses include:

• Railings and outdoor structures

• Industrial grating (tramex)

• Technical ladders

• Machinery components

• Agricultural stakes

Manufacturers like Polymec, based in Spain, operate under strict European standards such as UNE-EN 13706, ensuring structural quality in every profile produced.

Types of Pultrusion Profiles Available

One of pultrusion’s great strengths is its versatility. Standard shapes can be produced, but custom designs are also possible for specific applications. The most common include:

• Rods (smooth, ribbed, round, or square)

• Tubes (round, square, rectangular, telescopic)

• Flat bars (plain or special geometry)

• Angles, U-profiles, I-beams, dog bones, corner pieces

• Gratings (tramex)

• Special profiles: steps, manhole covers, skirting boards, tool components

In Polymec’s catalog, there are versions made with fiberglass, carbon fiber, or even graphene additives, offering enhanced properties such as thermal conductivity or chemical resistance.

Standards in Pultruded Profiles: Safety and Quality Assurance

Producing pultruded profiles is not just a technical process — it must also comply with international standards to ensure safety and performance.

In Europe, the key reference is EN 13706, which classifies profiles into two categories: E17 (standard) and E23 (high quality). Polymec manufactures under the latter, meeting stricter requirements for stiffness, strength, and dimensional tolerances.

These profiles are also tested under EN ISO 527 and EN ISO 14125 standards to evaluate their behavior under tension, bending, shear, and other mechanical loads.

Pultrusion and the Future: Growing Applications

The potential of pultruded profiles extends far beyond current uses. Their future is bright — especially in industries seeking sustainable, durable, and long-lasting materials. Emerging applications include:

• Supports for solar panels and wind turbines

• Railway and marine infrastructure

• Components for smart urban furniture

• Modular construction systems

• Lightweight parts for automotive and electric transport

Thanks to specialized companies like Polymec, which not only manufacture but also advise and customize solutions, pultrusion is positioning itself as a key technology in the shift toward a more efficient and sustainable industrial future.

Polymec has been present as a founding member of this cluster of companies, which aims to bring together all businesses in the composites sector in order to identify opportunities for innovation and business development through collaboration with other companies in the field, as well as to gain timely access to relevant information on issues affecting companies involved in composite manufacturing.
Our Manager, Mr. Santos Sánchez, was elected Vice President of the AESICOM cluster at its latest assembly.

Polymec is currently developing new products using natural fibers such as flax and slate fiber, in line with its R&D policy and its commitment to the environment.

This ambitious project is based on research aimed at developing a new pultrusion manufacturing process for the construction and automotive industries.

For more information, please visit the project’s website: www.coaline.eu

The first products made with graphene composites were presented at the JEC World Composites trade fair held in Paris this March. These are pultruded profiles with graphene that, thanks to this nanomaterial, improve the mechanical properties of conventional pultrusion profiles. They maintain the same weight but significantly increase strength — even surpassing that of steel, something unthinkable until the arrival of graphene.
At Polymec, we manufacture pultrusion profiles with graphene, marketed under the name CompoSmart, in Murcia.

The most innovative nanomaterial of recent times is set to play a key role in the future of composite materials. Graphene’s mechanical properties make it an ideal material to incorporate into composites to enhance their strength and durability.

At the JEC World in Paris, a section of a boat similar to the Graphenano One could also be seen — a vessel unveiled last October in Alicante to great anticipation, as it is the first boat built entirely from graphene-enhanced composite. Among its advantages: greater strength, lighter weight, higher speed, fuel savings, reduced material use during production, and lower environmental impact.

Graphenano Composites works with Gazechim for the supply of resins, which are enhanced with graphene in Graphenano’s laboratories.

On March 9th, the second meeting of the RECOTRANS Project consortium was held, coordinated by AIMPLAS, in which we are partners.
The goal of this project is to develop a new manufacturing system to produce multi-material composites suitable for the transport industry, achieving lightweight, high-quality materials.

The next steps will include defining and designing the three demonstrators, finalizing the formulation of the materials, setting the parameters for the laser technology, and integrating microwave technology into the resin transfer molding and pultrusion lines.