filamentwound

Filament winding is a composite manufacturing process for producing hollow, cylindrical, or spherical components by winding reinforcing fibers around a rotating mandrel under controlled tension and with a resin matrix. The term filamentwound is used to describe parts produced by this method.

The process uses continuous fiber tows or rovings of glass, carbon, aramid, or other materials, which may be impregnated with resin before winding (wet winding) or impregnated after winding (dry winding with resin infusion). The fibers are laid down on the mandrel at prescribed angles to tailor stiffness and strength, commonly 0, 90, and ±45 degrees.

Typical geometries include long pipes, pressure vessels, and storage tanks. After winding, the mandrel is cured to harden the resin and then removed in many cases for a hollow part. Some designs require post-curing to maximize resin crosslinking.

Materials and design choices influence performance. Glass fiber offers good strength at moderate cost; carbon fiber provides high stiffness and strength with lower weight; aramid fibers add toughness. Epoxy resins are common, with polyester and vinyl ester used in some systems.

Advantages of filament winding include high specific strength and stiffness, corrosion resistance, and the ability to tailor properties via fiber orientation. Limitations include higher tooling and layup costs, anisotropic behavior, susceptibility to impact damage, and manufacturing tolerances that can affect wall thickness uniformity. The method is widely used for pressure vessels, tanks, pipes, and other axisymmetric parts where weight reduction and corrosion resistance are priorities.