Benefits of GRP products

Glass-fibre-reinforced plastics combine many advantages of conventional materials, such as plastic, steel, wood and aluminium. This results in additional positive material properties and a higher level of performance at a lower cost.  

Below is a detailed overview of the key benefits of GRP products.  

Facts and applications:

Glass-fibre-reinforced plastic (GRP) has anti-magnetic properties due to the materials it contains, such as glass fibres and resins. In contrast to metallic materials that influence magnetic fields, GRP is not magnetisable. GRP is therefore ideal for applications in which magnetic interference must be avoided, such as in the electronics industry. In addition, the anti-magnetic properties of GRP allow it to be used in environments with electromagnetically sensitive devices without impairing their performance or accuracy. 

  • No electromagnetic influence: GRP does not interfere with magnetic fields and is therefore ideal for use in the vicinity of sensitive devices in the electronics industry.
  • Use in X-ray and magnetic resonance imaging: GRP is often used in medical facilities, particularly in the vicinity of X-ray magnetic resonance imaging, as it does not interfere with magnetic fields.

Excellent corrosion resistance makes GRP the obvious choice for applications in aggressive environments. Unlike conventional materials, such as steel or aluminium, GRP is not susceptible to corrosion, even after prolonged exposure to moisture, chemicals or salt water. In addition, the risk of galvanic corrosion is avoided by using GRP. These properties make GRP ideal for use in maritime environments, chemical plants, sewage treatment plants and other areas in which conventional materials would corrode quickly.

  • Corrosion: Resistant to moisture and water, while some metals, especially untreated steel, begin to rust quickly when exposed to moisture.
  • Economical: Glass-fibre-reinforced plastic is a more cost-effective alternative to stainless steel.
  • Service life: GRP can achieve a long service life in corrosive environments without significant material impairment.
  • Saltwater resistanceGRP shows no signs of corrosion or decomposition, even after prolonged contact with salt water, and is therefore ideal for maritime applications.
  • Maintenance costs: Due to the corrosion resistance of GRP, the maintenance costs are much lower than for steel or aluminium, which must be inspected and treated regularly.
  • Avoidance of galvanic corrosion: Since GRP is not metallic, no contact corrosion occurs on contact with other metals.
  • Chemical resistance: GRP can be used in environments such as sewage treatment plants, where it is constantly exposed to aggressive chemicals. Where steel or aluminium would quickly fail, GRP is resistant to many chemicals, including acids, alkalis and solvents.

The low weight of GRP enables professional pre-assembly of GRP structures in the factory. This makes it possible to transport even very large components and saves time and labour during assembly on-site – even in hard-to-reach places, as it is often possible to dispense with the use of special machinery. Cuts and drill holes can be made on site using simple tools; subsequent sealing is not absolutely necessary.

GRP has excellent electrical insulating properties. Unlike metallic materials, GRP does not conduct electricity and therefore provides a high level of insulation and protection against electric shock. Therefore, GRP is optimally suited for use in electrical switchgear, transformers, high-voltage systems and other applications in which separation of electrical components or protection against electrical discharges is required.

Benefits of electrical insulation of GRP:

  • Excellent insulation values
  • High surface resistance
  • High tracking resistance, CTI 600 
  • High impact strength 
  • Thermal stability: GRP retains its insulating properties over a wide temperature range of -50° C to +200° C, which allows it to be used in a variety of environments.

Comparison with other materials:

  • Metals: Metals are conductive and require additional insulating materials and measures to ensure safety against electrical voltages. GRP, on the other hand, offers high electrical insulation.
  • Ceramics: Ceramics also offer good insulation, but are brittle and prone to breakage. GRP combines high insulation values with flexibility and impact strength.
  • Plastic: Many plastics have good insulation properties, but GRP also offers mechanical strength and temperature resistance, which are required for many demanding applications. 

Glass-fibre-reinforced plastics are electrically insulating and non-conductive. In contrast to conventional metallic materials, no earthing is required. Products such as GRP grating panels and covers are therefore ideal for use in the rail and electrical industries.

MaterialDensityTensile strengthSpecific tensile strength 
 kg/dm³MPaMPa*dm³/kg
GRP profiles1.9385202.6
Oak0.5890155.2
PP0.913538.5
PA GF300.63124196.8
Structural steel7.8536045.9
Tool steel7.851180150.3
Aluminium2.718066.7
Titanium4.5700155.6

Benefits of GRP's lightness

  • Ease of use: The low weight of GRP makes it easier to handle and install, resulting in lower labour costs.  
  • Lower transport costs: Lighter materials significantly reduce transport costs, as more material can be transported per load.  
  • Greater safety: The lower weight reduces the risk of injury during assembly and handling.  
  • Less structural support: Due to the lower weight, the need for heavy support structures and foundations can be reduced, which lowers the overall cost of the construction. 

Density comparison

  • GRP: The density of GRP is about 1.8 to 2.0 g/cm³.  
  • Steel: Steel has a density of about 7.8 g/cm³, which is about four times the density of GRP.  
  • Aluminium: Aluminium has a density of about 2.7 g/cm³, which is about 1.5 times the density of GRP.  
  • Wood: Wood (depending on the type) has a density of about 0.5 to 0.9 g/cm³ and is therefore lighter than GRP, but does not have the same strength and durability.  
  • Other plastics: Many conventional plastics have a density of about 0.9 to 1.5 g/cm³, which makes GRP superior due to its higher strength and temperature resistance. 

Glass-fibre-reinforced plastics are electromagnetically permeable. This high permeability to frequencies and waves prevents electromagnetic interference, which is why GRP products can be ideally used in areas such as mobile communications, communication transmission and airports.

Facts and advantages

  • Minimum electromagnetic interference: GRP does not cause electromagnetic interference, as it allows electromagnetic waves to pass almost unhindered. This is particularly important in areas where sensitive electronic devices are operated.  
  • Improved signal quality: Due to the high permeability of GRP, signals can be transmitted undisturbed, which does not affect the signal quality in communication applications.  
  • In contrast to steel and aluminium, GRP is non-conductive and non-magnetic. It does not block or reflect electromagnetic waves and is therefore ideal for applications in which minimal attenuation is desired.  

Areas of application

  • Mobile telephony and communications: GRP antenna covers and housings are ideal for mobile phone towers, as they do not impair the signal quality. 
  • Airports: GRP is ideal for use in airports to ensure that communication between control towers, aircraft and ground devices can take place unhindered. 

GRP is highly weather-resistant, making it a robust and durable composite material for outdoor use. In contrast to conventional materials, such as wood or steel, GRP is insensitive to the harmful effects of weathering, such as rain, snow, sun and temperature fluctuations. 

Due to its composition, GRP is resistant to corrosion and rot and is therefore ideal for use in environments with high humidity, salty air or strong temperature fluctuations. These properties make GRP the material of choice for a wide range of outdoor applications, such as façade elements, bridges, railings, platforms and jetties. 

  • Steel: Steel must be regularly maintained and protected against corrosion. Typically, steel must be repainted or coated every 5 to 10 years to prevent rust and corrosion. Without regular maintenance, steel can undergo severe corrosion and fail structurally within 20–30 years.  
  • Aluminium: Aluminium is more resistant to corrosion than steel, but can corrode in salty or chemical environments. Aluminium also requires regular maintenance and may require surface treatment every 10–15 years.  
  • Glass-fibre-reinforced plastic: Glass-fibre-reinforced plastic requires minimal maintenance and can last 50 years or longer without its mechanical properties being significantly affected. GRP does not have to be painted or coated to maintain its structural integrity, which leads to cost savings in the long term.

Fire protection with GRP

According to customer requirements, GRP is flame-retardant depending on the composition of the material used. Depending on the application, there are various fire protection requirements that we can implement accordingly.

  • Flame-retardant: GRP can be made flame-retardant using additives.
  • Self-extinguishing: The corresponding GRP profiles are self-extinguishing and stop the spread of flames as soon as the source of fire or energy is removed.
  • Limited smoke production: GRP is free of halogens and develops less smoke in the event of fire than many other plastics.  The smoke is also less toxic, increasing safety for people.

Linear stress–strain behaviour is a material property that describes how a material reacts to a load. A material with a linear stress–strain behaviour shows a proportional relationship between stress (σ) and strain (ε) until it reaches its elastic limit. Glass-fibre-reinforced plastic (GRP) has such a linear relationship, which makes it a predictable material for a wide range of applications.

Advantages of linear stress–strain behaviour

  • Predictable behaviour: The linear stress–strain behaviour of GRP means that the deformation of the material under load is directly proportional to the applied stress. This enables accurate calculations and predictions of material behaviour under different load conditions.
  • A high level of safety and reliabilityGRP structures are particularly safe and reliable due to their predictable behaviour. Engineers can calculate exactly how the material behaves under load, increasing planning and safety reserves.

Facts and figures
 

  • Elastic modulus: GFRP has an elastic modulus of around 17–40 GPa, typically 25 GPa for structural profiles, making it stiffer than many conventional plastics, but less stiff than steel (210 GPa) and aluminium (70 GPa).  
  • Tensile strength: GRP can achieve a tensile strength of 350–800 MPa, while steel typically reaches 350–900 MPa, and aluminium, 70–400 MPa.  

Glass-fibre-reinforced plastic (GRP) offers excellent performance over a wide temperature range of -50 °C to +200 °C. This property makes GRP an ideal material for applications in extreme environments that require thermal stability and resistance. Compared to thermoplastics, GRP offers several advantages, including lower thermal expansion and greater structural integrity in the event of temperature fluctuations. 

Benefits of GRP in a wide temperature range

  • Wide temperature range: GRP can be used in a temperature range of -50 °C to +200 °C.  
  • Limited thermal expansionGRP has a low coefficient of thermal expansion, which means that it retains its shape and size better in the event of temperature fluctuations. 

The thermal conductivity of GRP is lower than that of metals such as aluminium or steel. As GRP consists mainly of glass fibres and resin, the thermal conductivity of GRP is lower than that of metals, meaning that glass-fibre-reinforced plastics can be regarded as thermally insulating. 

In general, the thermal conductivity of GRP is significantly lower than that of metals and almost as low as that of wood. This makes GRP an attractive material for applications where low heat transfer is required, such as building insulation or window and door profiles.  

In addition, the low thermal conductivity of GRP offers advantages in environments with extreme temperatures, as the material helps to insulate heat or cold and thereby contributes to thermal stability. 

Thermal conductivity of different materials - Fibrolux GmbH
Thermal conductivity of different materials

Benefits of GRP thermal insulation

  • Low thermal conductivity: GRP has low thermal conductivity; i.e., it conducts heat poorly. This makes it an excellent insulating material.  
  • Thermal stability: GRP retains its mechanical and physical properties over a wide temperature range and is therefore suitable for extreme environments.  
  • Avoidance of thermal bridges: In construction, GRP can help avoid the thermal bridging and condensation that often occurs in metal structures.  

Glass-fibre-reinforced plastic (GRP) is characterised by its high load-bearing capacity, which makes it an ideal material for many industrial applications. Compared to conventional materials, such as steel, aluminium, other plastics and wood, GRP offers an excellent combination of strength, flexibility and durability.

Benefits of GRP's high load-bearing capacity

  • Excellent tensile strength: GRP can withstand tensile stresses of up to 1000 MPa and is therefore extremely resilient. This high tensile strength enables GRP to bear high loads without breaking or significant deformation.  
  • High bending strength: GRP has a bending strength of 250 to 500 MPa, which means that it can withstand high bending loads without breaking or failing.  

Comparison with other materials:

Material

Tensile strength

Bending strength

Elastic modulus

Glass-fibre-reinforced plastics (GRP)

500–100 MPa

250–500 MPa

17–40 GPa

Steel

350–900 MPa

250–550 MPa

210 GPa

Aluminium 

7–250 MPa (standard alloy)

to 570 MPa (high-strength alloys)

100–200 MPa

70 GPa

Polypropylene (PP)

20–40 MPa

30–40 MPa

1–2 GPa

Wood (depending on the type of wood)

40–80 MPa

50–100 MPa

10–15 GPa

Glass-fibre-reinforced plastic (GRP) is a material that offers considerable cost savings in various industries due to its unique properties. The following are some aspects of how GRP contributes to these benefits:

  • Durability: GRP is extremely resistant to corrosion, moisture and many chemicals. As a result, the service life of products made of GRP is often significantly longer than that of conventional materials, such as steel, aluminium or wood.
  • Very low maintenance: Since GRP does not rust and is very resistant to environmental influences, it requires less maintenance. This not only saves direct maintenance costs, but also downtime and the associated production losses.
  • Energy efficiency: Due to the excellent insulating properties of GRP, energy losses can be minimised, for example, in insulation or in the construction industry. This leads to lower heating and cooling costs.
  • Production costs: Production processes for GRP, such as the pultrusion process, are often less energy-intensive and can be carried out faster than comparable processes for metal, which leads to cost savings. 
  • Design freedom and material savings: GRP can be moulded into complex shapes that are difficult to achieve with conventional materials. As a result, the material can be used more efficiently, and waste can be reduced. In addition, the freedom of design often allows for the omission of additional components, reducing installation costs.
  • Assembly: The possibility of pre-assembly in the factory and the simple handling without special tools shorten the assembly time on site. In addition, fewer personnel are required, which further reduces costs.