Manufacturers of FRP pipe and GRP pipe in the energy industry use two different processes to produce composite pipe. These processes are Filament wound and rotary casting. The only things these processes have in common are fiberglass strands or other material that can be wrapped around or in a mold to produce strong tubular and engineered with characteristics that conquer weaknesses in metals. These fiberglass strands are later encased in an epoxy or resin solution that binds the strengthening material into a robust fit for purpose tubular.
The energy industry has replaced metal applications with composite pipe for areas where metals corrode or where lightweight application is needed. These composite tubes don’t need any introduction and known as Glass Reinforced Epoxy (GRE).
The variations in manufacturing methods are significant to the strength profile to be possessed by the composite pipe. Any inclusion of trapped air would be considered as weak link.
How manufacturing companies produce composite pipe using filament winding method?
Filament winding method involves passing of fiber strands via a resin bath and winding them under tension with the help of rotary mandrel. Once wounding is completed, it is heated in the over for curing process. Curing is the most common method used for producing composite pipe. Manufacturers apply curing method to create composite pipe out of distinct materials.
Benefits of filament winding –
- This method of manufacturing composite pipe is economical and speedy.
- Resin content can be regulated by metering the resin over each fiber tow via nips or dies.
- Fiber cost is minimized as there is no requirement for a secondary process to transform fiber into fabric before use.
- Composite pipes made from filament wound method are corrosion resistant, chemical resistant, can withstand abrasion and have a low weight to strength ratio
- The process produces a material component of straight fibers that engineers laid in a complex pattern to match applied loads.
- The filament wound method lets reinforcement to be placed in areas where stress will incur more, such as collars.
- Dual helical winding process can provide more durable pipes
Limitations of filament winding –
- Engineers can only produce convex shaped components
- Mandrel costs can be high
- It’s never easy to lay the fiber exactly along the component length
- The external surface of the product is not appealing
- Properties of the product in terms of mechanical, safety and health are lowered with the use of low viscosity resins with their attendant
- Moisture and air inclusions can take more space which degrades the strength and penetration resistance of the pipe.
FRP pipe manufacturers still find this method economical and thus, they apply it for producing composite piping solutions.