What are Pultruded GRP Profiles and why do they make a superior structural profile than steel?

In the realm of modern industry, Glass Reinforced Plastic (GRP) profiles have emerged as a game-changer, heralding a new era of versatility, durability, and cost-effectiveness. These profiles have swiftly gained traction, outshining traditional steel counterparts in various applications. Join us on a journey into the realm of GRP pultruded profiles, as we unravel what they are, why they’re the preferred choice over steel profiles, where they’re deployed, and the intricate process behind their creation.
What is a GRP Pultruded Profile?
Before we dive into GRP profiles, it’s crucial to understand the process behind their creation. GRP profiles are often pultruded, a manufacturing method that involves pulling reinforcing fibres through a isophthalic polyester resin bath, then through a shaping die to produce a continuous profile. This process allows for precise control over the profile’s dimensions and properties.

Pultrusion is a continuous process, meaning profiles can be produced in long lengths with consistent quality. The fibres used in pultrusion are typically glass, hence the term “Glass Reinforced Plastic.” These fibres provide strength and reinforcement to the finished product, making GRP profiles robust and resilient.
Why are Pultruded GRP Profiles Popular Compared to Steel Profiles?
GRP profiles offer several advantages over traditional steel structural profiles, making them a popular choice in various industries:
Excellent Corrosion Resistance:One of the most significant advantages of GRP is its resistance to corrosion. Unlike steel, which can rust and degrade over time, GRP profiles are impervious to corrosion, making them ideal for outdoor and harsh environments.
Lightweight:GRP profiles are significantly lighter than steel being more comparable to aluminium in weight, making them easier to handle and transport. This lightweight nature also reduces installation time and labour costs.
High Strength to Weight Ratio: Despite being lightweight, GRP boast a high strength-to-weight ratio, meaning they offer excellent structural integrity without adding unnecessary bulk.
Design Flexibility:GRP profiles can be moulded into virtually any shape or size, offering unparalleled design flexibility. This versatility makes them suitable for a wide range of applications, from structural supports to architectural features.
Low Maintenance:GRP profiles require minimal maintenance compared to steel. They do not require painting or protective coatings to prevent corrosion, reducing long-term maintenance costs.
Electrical Insulation:Unlike metal profiles, GRP products are non-conductive, making them ideal for applications where electrical insulation is required.
All these factors combine to make GRP Composites a cost-effective alternative to steel, which is widely praised for its strength and durability.
Where are GRP Profiles Used?
GRP profiles find applications across various industries and sectors, with each industry utilising a range of GRP Pultruded Profiles including Box Sections, Angle Profiles, GRP Square Tubes and GRP i-beams. The markets where GRP structural profiles are used are:
  • Construction: GRP profiles are commonly used in construction for structural elements such as beams, columns, and trusses. Their corrosion resistance makes them ideal for outdoor and coastal applications.
  • Infrastructure: GRP profiles are used in infrastructure projects such as pedestrian bridges, walkways, and railings due to their durability and lightweight nature.
  • Transportation: GRP profiles are utilised in the transportation industry for applications such as bus shelters, platforms, and access ramps. Their lightweight construction and corrosion resistance make them suitable for outdoor use in transportation hubs.
  • Marine: Given their resistance to corrosion, GRP profiles are extensively used in the marine industry for boat building, docks, and offshore structures.
  • Renewable Energy: GRP profiles play a crucial role in renewable energy projects, particularly in wind energy, where they are used in turbine blades and support structures.
  • Chemical Processing: The corrosion-resistant properties of GRP profiles make them well-suited for use in chemical processing plants, where exposure to corrosive chemicals is common.
So GRP is commonly used in industrial, construction, marine and transportation (particularly in the railway sector) markets. The range of use cases is so wide that we can scarcely cover them all here. So why not check out some of our Case Studies for more information.
How are GRP Profiles Made?
The intricate process of manufacturing GRP profiles involves several meticulous steps:
  • Resin Impregnation: Continuous glass fibres are impregnated with a thermosetting resin, serving as the matrix that binds the fibres together and imparts structural integrity.
  • Pultrusion: The impregnated fibres undergo pultrusion, wherein they are pulled through a heated die, cured, and shaped into the desired profile with precision and consistency.
  • Finishing Touches: Post-pultrusion, profiles are meticulously cut to size and subjected to finishing processes such as sanding or drilling to meet exact specifications.
  • Stringent Quality Control: Rigorous quality control measures are enforced throughout the production process to ensure profiles meet stringent standards for strength, dimensions, and surface finish.
In summation, our GRP profiles are manufactured to exacting standards, are suitable for a wide range of industries and used in many differing applications in projects as diverse as water treatment works, to electrical substations with their great thermal and electric non-conductivity.

Engineered Composites are proud to offer a range of profiles in all essential types and sizes and can source your specific requirements. All our structural profiles come with a wall thickness of over 5mm meet the higher performance E23 grade, while those at 3-5mm are E17 grade. All GRP Profiles are BS EN 13706 compliant and come in 6m lengths as standard. See our full range of GRP Pultruded Profiles here.