Filament Wound Composite Curing Technology: Strength and Precision in Every Turn - Part 1
The world of composite materials is filled with remarkable technologies used for the manufacture of many products. Filament winding is a process used in the composites industry to create strong, lightweight cylindrical and tubular structures. In this two-part blog, we will explain the process of filament wound composite curing, discuss the common products and industries that use it, and detail the key features of an industrial oven used for this process.
What is Filament Winding?
Imagine crafting incredibly strong, lightweight, and precisely shaped parts using continuous fibers and resin. That's the essence of filament winding. This technique involves winding resin-impregnated fibers in a controlled pattern around a mandrel, which serves as a reusable mold. Alternatively, a permanent inner material is utilized in lieu of a mandrel, and it remains part of the final part. This creates a composite overwrapped vessel or COPV used for hollow structures like pipes, water tanks, pressure tanks, golf clubs, and aircraft components. By combining the tensile strength of the wound fibers with the structural integrity of the cured resin, this technology provides the best of both worlds.
The Curing Process
After winding, the filament wound structures are cured in an oven at 200°F to 400°F to harden the resin. Top load ovens or batch ovens with a load cart and rotator are common oven designs for the curing process. For both designs, the mandrels must be kept rotating while being cured to prevent the resin from sagging due to gravity, ensuring a round profile.
Common Products and Industries
Filament wound composite structures can be found in a wide variety of industries and products, including:
- Aerospace: Aircraft components
- Marine: Pressure tanks, pipes, boat hulls
- Energy: Wind turbine blades, power transmission poles
- Automotive: Drive shafts
- Sports and recreation: Golf clubs, fishing rods, bicycle parts
- Military: Missile housings, rocket casings
Part 2: Curing Oven Design and Features for Filament Wound Composites
When designing a curing oven for filament wound composite parts it is important to consider specific features and options to prevent curing defects. Learn more about the key design features to consider for your next filament wound composite curing oven in part 2 of this blog series!
Filament Winding Composites FAQs
What industries use filament wound composites?
Filament wound composites are commonly used in aerospace, automotive, energy, marine, and recreation industries. Common products manufactured using filament wound composites include pressure vessels, pipes, water tanks, boat hulls, rocket motor casings, and wind turbine blades.
What is a composite overwrapped pressure vessel (COPV)?
A composite overwrapped pressure vessel (COPV) is a pressure vessel made using the filament winding process in which resin-impregnated composite fibers are wrapped around a permanent inner liner instead of a removable mandrel. The liner, made of aluminum for example, remains part of the finished structure, while the composite overwrap provides high strength and structural reinforcement. COPVs are commonly used to manufacture hollow composite structures such as high performance pipes, water tanks, pressure vessels, golf club shafts, and aircraft components.
What is the filament winding process in composite manufacturing?
Filament winding is a composite manufacturing process in which resin-impregnated fibers are wound around a rotating mandrel in controlled patterns. The fibers build up layers to form a strong cylindrical or tubular structure. After winding, the part is placed in a curing oven where heat hardens the resin and permanently bonds the fibers.