In short: FRP (fiberglass reinforced plastic) is a composite material: strong glass fibers carry the load, and a thermoset resin holds the fibers in place and protects them from the environment. The result is a material that does not rust, does not conduct electricity, and weighs far less than steel. In the UK, Europe, Australia and the Middle East the same material is usually called GRP (glass reinforced plastic). The resin, the fiber layout and the manufacturing process decide how a given FRP product performs, so the right specification matters more than the generic name.
FRP is now standard in chemical plants, water and wastewater treatment, power stations, offshore platforms and food processing. It is used for walkways and platforms, cable trays, tanks, pipes, scrubbers and cooling towers.
What FRP is made of
Every FRP product has two essential ingredients, plus optional additives.
1. Glass fiber reinforcement
Glass fibers provide stiffness and strength. They come in several forms:
- Roving: continuous bundles of parallel fibers. These are used where strength in one direction matters, such as the bearing bars of grating, pultruded profiles and the hoop layers of filament-wound tanks.
- Mat: randomly oriented chopped or continuous fibers. Mat gives strength in all directions within the sheet and is common in hand lay-up and in the transverse layers of pultruded shapes.
- Woven fabrics: fibers woven at fixed angles for controlled strength in two or more directions.
- Surface veil: a thin glass or synthetic tissue that creates a resin-rich surface. It improves corrosion resistance and helps protect the fibers from UV exposure.
How much glass a product contains, and which way the fibers run, changes its properties a great deal. For example, molded fiberglass grating is resin-rich: a US FRP grating manufacturer gives about 35% glass and 65% resin for molded grating. Pultruded grating is fiber-rich, with much more glass running along the bars, which gives it more strength in that direction.
2. Thermoset resin matrix
The resin binds the fibers together, transfers load between them, and forms the barrier against chemicals and water. Unlike thermoplastics such as PVC or HDPE, thermoset resins cure through a chemical reaction and do not re-melt when heated. The common families are:
- Orthophthalic polyester: general-purpose and economical. It suits mild conditions.
- Isophthalic polyester: better chemical and water resistance than ortho. It is widely used for industrial grating and water tanks.
- Vinyl ester: tougher, and resists a wider range of acids, alkalis and oxidizers. It is the usual choice for chemical tanks, scrubbers and severe grating applications.
- Phenolic: chosen mainly for fire performance: low flame spread and low smoke.
- Epoxy: high mechanical performance. It is more common in aerospace and pipe systems than in industrial grating.
We compare these in detail in Polyester vs Vinyl Ester vs Phenolic Resin.
3. Additives
Fillers, pigments, UV inhibitors and fire-retardant additives are added to the resin. They set the color, slow surface weathering and improve fire performance. Each additive is a trade-off: a fire-retardant package, for example, can change other properties. Ask your supplier which additives are in the system they quote.
How FRP is manufactured
The process determines the shape, the fiber layout and the cost of the product. The four you will meet most often are:
| Process | How it works | Typical products |
|---|---|---|
| Open molding (grating) | Rovings and resin are laid in layers into a grid mold (often heated) and cured as one piece | Molded grating, stair treads |
| Pultrusion | Fibers are pulled through a resin bath and a heated die in a continuous process | Pultruded profiles, handrails, ladders, cable tray rails |
| Filament winding | Resin-wet fibers are wound onto a rotating mandrel at controlled angles | Pipes, tanks, ducts |
| Hand lay-up / spray-up | Mat and fabric are laid into an open mold and wetted out by hand or spray | Covers, hoods, custom fittings, tank heads |
Each process is explained step by step in How FRP Is Made.
Key properties of FRP
Corrosion resistance
FRP does not rust. With the right resin it resists many acids, salts, chlorides and wastewater atmospheres that attack carbon steel and even some stainless grades. This is the main reason FRP is used in chemical plants, desalination and wastewater facilities. Resistance depends on the chemical, concentration and temperature, so always check the resin manufacturer's chemical resistance data for your exact service. Our chemical resistance guide explains how to use those tables.
Light weight
FRP has a much lower density than steel, so panels and profiles can often be handled by two people without a crane. That reduces installation time, transport cost and the load on existing structures.
Electrical and thermal insulation
Standard glass-fiber FRP is non-conductive, which makes it useful near live equipment, in substations and for cable trays and ladders. It also conducts heat poorly, so handrails stay comfortable to touch in sun or frost. One caution: because ordinary FRP is an insulator, it cannot serve as a protective grounding conductor. Bonding and grounding remain part of the electrical design.
Design freedom and customization
Molds, dies and winding programs can be made for almost any size or shape, and color is built into the resin. This is why most FRP is made to order. At FIBROVX every product can be customized: dimensions, resin system, color, surface finish, new molds and OEM labeling.
Limitations to understand
FRP is not a universal replacement for steel. Good specifications account for:
- Lower stiffness. FRP's modulus of elasticity is much lower than steel's, so deflection usually governs design rather than strength. Grating and profile load tables are typically based on a deflection limit.
- Temperature limits. Each resin has a maximum service temperature. Above it, strength and chemical resistance fall.
- UV weathering. Unprotected surfaces can chalk and expose fibers over years outdoors. UV inhibitors, a veil or a protective coating slow this down.
- Fire behavior. FRP is combustible. Fire-retardant or phenolic systems are available. Ask for the test report your project requires, for example ASTM E84 surface burning results.
- Creep. Under long-term sustained load, FRP deflects further over time. Design codes and manufacturer data account for this with reduction factors.
Where FRP is used
- Walkways and platforms: FRP grating, stair treads, handrails
- Structures: pultruded profiles for frames, supports and enclosures
- Electrical: cable trays, cable supports, insulating ladders
- Liquids: storage tanks, pipes, septic tanks
- Air pollution control: scrubbers, fans, demisters, odor control units
- Cooling: cooling towers and fill media
- Site and building: manhole covers, roofing sheets, marker posts
Browse all product families on our collections page.
How to specify FRP correctly
When you request a quote, include:
- Application and environment: chemicals, concentration, temperature, indoor or outdoor exposure.
- Loads and spans: design load, support spacing and allowable deflection.
- Dimensions or drawings: panel sizes, profile sections, tank capacity.
- Fire and safety requirements: required standards or test reports.
- Color and surface: grit, concave or covered top, pigment.
- Quantity and destination: this affects packing and freight.
Need a quote or a drawing check?
FIBROVX manufactures FRP products in our own factory in China and builds every item to order: sizes, resin system, color, molds and OEM branding. Send your application, dimensions or drawing, quantity and destination port.
Request a Quote
Watch: What Is FRP? in 27 Seconds
FAQ
Is FRP the same as fiberglass?
In everyday use, yes. "Fiberglass" often refers to the composite itself, though strictly it means the glass fiber. FRP and GRP describe the same family of glass-fiber composites. See FRP vs GRP vs Fiberglass.
Is FRP stronger than steel?
Strength per unit weight can be high, especially in pultruded products along the fiber direction. But FRP is much less stiff than steel, so it deflects more under the same load. Compare products using load tables, not the generic material name.
Does FRP conduct electricity?
Standard glass-fiber FRP is an electrical insulator. This is why it is used for cable trays and ladders near live equipment. Surface contamination and moisture can affect surface resistance, so follow the electrical safety rules that apply on your site.
How long does FRP last?
Service life depends on the resin, the environment, UV exposure and maintenance. Correctly specified FRP is widely used in corrosive plants because it avoids the rust that shortens steel's life. Ask for references or data relevant to your environment rather than relying on a generic figure.
Can FRP be recycled?
Thermoset FRP cannot be re-melted like thermoplastics. Mechanical grinding into filler, and cement-kiln co-processing, are used in some regions. Long service life and low maintenance are usually its main environmental advantages.
Can FRP products be made to custom sizes and colors?
Yes. Most FRP is made to order. FIBROVX customizes dimensions, resin, color, surface and molds, and offers OEM branding.
Related guides
- How FRP Is Made
- FRP vs GRP vs Fiberglass
- Polyester vs Vinyl Ester vs Phenolic Resin
- Technical Resources: datasheets and drawings on request
- Custom FRP Manufacturing: Sizes, Resins, Colors, Molds and OEM Explained
- How to Import FRP from China: Specs, QC Inspection and Container Loading
- Industries we serve
- Emerging industries we serve
- Can FRP Be Recycled? Cement Kiln, Mechanical and Pyrolysis Routes
- Bio-Based and Recyclable Thermoset Resins: What Is Coming for FRP
Sources
- A US FRP grating manufacturer, "Molded vs. Pultruded Fiberglass Grating" (glass content of molded and pultruded grating)
- Cable Tray Institute, "Codes and Standards" (non-metallic cable tray standards): https://www.cabletrays.org/codes-and-standards/
- An FRP grating supplier, "FRP Grating ASTM E84 Class 1 Fire Rating" (ASTM E84 flame spread classes)