Fiberglass Reinforced Plastic Grating or FRP Grating has become a popular alternative to conventional metal grating used to make walkways, platforms and other kinds of industrial flooring. FRP Grating resists corrosion and does not conduct heat and electricity. Thus, it is a more durable and safer option as compared to metal grating. FRP Grating is manufactured by blending fibreglass and resin. The resin imparts anti-corrosion properties to it while fibreglass makes it strong.
Categorisation of FRP Grating
FRP Grating is categorised into Moulded and Pultruded FRP Grating.
Moulded FRP Grating is manufactured by laying glass fibres continuously in horizontal and vertical directions inside a metal mould. Resin is then added to the glass fibres in layers. After weaving the glass fibres and the resin, the panel is cured by heating the mould. Finally, the cured panel is removed from the mould. The FRP grating panel can either have a smooth surface finish or grit can be incorporated into the surface. Moulded FRP grating panels come in standard sizes and provide multidirectional strength. Multidirectional strength means extra reinforcement is not required for moulded FRP grating.
Pultruded FRP Grating is made by a process known as Pultrusion. This is a multistep process which binds the glass fibres with resin. In the first step, fibreglass roving and other materials such as mat and woven or stitched fabric are passed through a bath containing resin. This process infuses resin into the glass fibres. In the second step, the resin impregnated glass fibres are passed through a preforming die to impart any geometrical shape to them. Thereafter, the fibres are passed through the heated die. The resin is cured inside the heated die. The glass fibres then solidify in the same shape as the cavity of the die. In the final process, an automatic cutter cuts the pultruded grating sections to the required lengths. Pultruded FRP grating can be customised to any size and shape. The glass to resin ratio is high in this grating which makes it more sturdy and durable as compared to Moulded variety. However, Pultruded FRP grating costs more.
Moulded FRP Grating can be made using the following types of resins.
- Corvex is isophthalic polyester resin which is used to make moulded FRP gratings used in highly corrosive locations such as chemical plants, wastewater treatment plants and many more.
- Vi-Corr is vinyl ester resin which provides very high resistance against corrosion. Thus, it is used for making moulded FRP gratings for use in highly acidic environments.
- XFR or Xtra Fire Retardant resin is used to make moulded FRP gratings for places with high risk of fire. This is because this resin does not allow fire to spread.
- FGI-AM is food grade isophthalic polyester resin which makes the surface of the moulded FRP grating anti-bacterial in nature.
Following kinds of resins are used for making Pultruded FRP Grating.
- VEFR is vinyl ester resin having a flame spread rating of 25 or less. It is also resistant against both acids and alkalis.
- Flame resistant Phenolic resin with flame spread rating ranging between 10 and 15. It is commonly used for making pultruded FRP gratings for offshore applications.
- ISOFR is isophthalic polyester resin which is used to make pultruded FRP gratings for moderately corrosive locations.
Features of FRP Grating
FRP grating is resist corrosion which make them suitable for harsh environments. Non-magnetic nature protects them against harmful effects of magnetic fields. High resistance to heat and fire make them suitable for installations at risk of fire hazard. FRP gratings can withstand high loads because of their greater strength to weight ratio. Finally, low weight of FRP gratings make them easy to store and transport.