What is GRP?
Also known as:
GRP (Glass Reinforced Polymer)
FRP (Fibre Reinforced Polymer)
GFRP (Glass Fibre Reinforced Polymer)
GRP is the abbreviation of Glass Reinforced Polymer, meaning it is a man-made resin based material which makes it a polymer, reinforced with glass. Polymer itself is extremely strong. It is a fiber material and in contrary to how it sounds it is very durable. It is resistant to most chemicals, stretching and shrinking, resistant to mildew and abrasion as well. When it is reinforced with glass, it becomes a structural polymer. You can build and construct many things as well as cable ladders, trays, posts etc which are resistant to fire and highly corrosive environments. Further to these, GRP does not conduct heat. It has extra durability to adverse weather conditions and has UV stability which makes it an excellent candidate for outdoor applications, even for Wind substations built in the middle of the sea. The range is composed of ladders, trays or so called troughs in rail business language and it can support any type of power and data cable runs.
Image © 2020 Exel Composites Plc.
GRP is manufactured through a process called pultrusion. Above you see the glass rovings going into the resin bath, then mats are placed on to these to create the profile first and goes into the die which shapes and cures it in the form of a ladder or tray, and at the end of the line it is cut to the required length.
Pultruded Technology is used whenever the benefits of whole life cost are appreciated and although the process was originally developed in the USA around 50 years ago, low levels of technology have traditionally meant high costs and therefore applications suited mainly to the extreme longevity of the material.
The mechanical properties of GRP can vary widely depending on the matrix fibre combination, fillers, veils, reinforcement design, and manufacturing methods.
These properties allow an initial comparison of different types of composites as well as providing a benchmark against which to measure the success of the specific recycling process in achieving acceptable material properties.
Production Methods
Compression Moulding:
Light / Medium Duty
1.Enough structural strength for light and medium duty applications (Low/medium load carrying )
2.Glass content is around 20-25%
3.High filler content
4.Orthothalic resin or Isopthalic resin which might end up having a low fire retardancy
5.Good for indoor applications, its manufacturing results in nice bends and better shape
Lamination through Pultrusion:
Heavy duty
1.High structural strength for heavy duty applications (high load carrying)
2.Glass content is around 40-55%
3.Low filler content
4.Isopthalic polyester resin which has a good corrosion/fire performance, and Acrylic resin resulting in better corrosion, fire performance and low smoke/fumes
5.Good for indoor and outdoor applications thanks to the UV surface veil applied during the lamination