Filament winding and its Manufacturing Process

23 April 2024 by Vinjamuri Innovations in Non classé

Filament winding is a specialized manufacturing process used to create composite structures, particularly those with cylindrical shapes such as pipes, pressure vessels, and rocket casings. It involves the precise and controlled application of continuous fibers (such as carbon fiber or glass fiber) onto a rotating mandrel or mould, which is then cured to create a rigid, lightweight, and strong composite part.
The process typically involves several key steps:
1. Preparation of Mandrel or Mold: The first step in filament winding is preparing the mandrel or mould to the desired shape and size of the final product. The mandrel is usually made of metal or composite material and is mounted on a rotating axis. There are specialised machineries available that help achieve faster results in filament winding.

2. Selection of Fiber Material: The choice of fiber material depends on the specific requirements of the application. Carbon fibers are known for their high strength and stiffness, making them suitable for applications where lightweight and high performance are essential. Glass fibers (E-Glass or S-Glass), on the other hand, offer good strength and corrosion resistance at a lower cost, making them suitable for a wide range of applications. Other materials like Kevlar are used for specific applications

3. Preparation of Resin Matrix: The fibers are impregnated with a resin matrix, typically epoxy, polyester, or vinyl ester resin. The resin matrix acts as a binder, holding the fibers together and providing additional strength and stiffness to the composite structure.

4. Filament Winding Process: The winding process begins with the continuous fibers being fed through a resin bath to impregnate them with the resin matrix. The impregnated fibers are then wound onto the rotating mandrel in a specific pattern under tension. The winding pattern can vary depending on the desired properties of the final part, such as hoop or helical winding. Again, specialised software’s are available that help achieve faster and accurate results.

5. Curing: Once the desired number of layers has been wound onto the mandrel, the composite structure is cured to harden the resin matrix. Curing is typically done in an oven at elevated temperatures to initiate the chemical reaction that transforms the resin from a liquid to a solid state. The curing temperature and duration vary depending on the resin system used and the size and complexity of the part being manufactured.

For carbon fiber winding, curing temperatures typically range from 120°C to 180°C (250°F to 350°F), depending on the specific resin system and the desired mechanical properties of the final part.
For glass fiber winding, curing temperatures are generally lower, ranging from 80°C to 120°C (175°F to 250°F). Glass fiber composites typically require longer curing times compared to carbon fiber composites due to the slower reaction kinetics of the resin matrix.
Overall, filament winding offers several advantages over other manufacturing processes, including the ability to create complex shapes with minimal material waste, high strength-to-weight ratio, and excellent fatigue resistance. It is widely used in industries such as aerospace, automotive, marine, and construction for producing lightweight and high-performance composite parts.