Filament winding of fiberglass

Filament winding

Filament winding is a manufacturing technique mainly used to manufacture open (cylindrical) or closed structures (pressure vessels or storage tanks). The process involves winding filaments on a male mold under tension. The mandrel rotates while the wind eye on the carriage moves horizontally to lay the fiber in the desired pattern. The most common filaments are carbon fiber or glass fiber, which are covered with synthetic resin during winding. Once the mandrel is completely covered to the required thickness, the resin will cure. Usually, the mandrel is placed in an oven for this purpose, although sometimes radiant heaters are used while the mandrel is still rotating in the machine. After the resin is cured, the core rod is taken out, leaving a hollow final product. For some products (such as gas cylinders), the "mandrel" is a permanent part of the finished product, forming a liner to prevent gas leakage, or as a barrier to protect the compound from the fluid to be stored.

Filament winding is very suitable for automation and has many applications, such as pipes and small pressure vessels that can be wound and cured without manual intervention. The control variables of winding are fiber type, resin content, winding angle, tow or width, and thickness of fiber bundle. The angle from which fiber affects the performance of the final product. Large-angle "hoops" will provide circumferential or "burst" strength, while smaller-angle patterns (polar or spiral) will provide greater longitudinal tensile strength.

Products currently produced using this technology include pipes, golf clubs, reverse osmosis membrane shells, paddles, bicycle forks, bicycle rims, power supplies and transmission rods, pressure vessels, missile shells, aircraft fuselages and light poles, and yacht masts.