Getting it wound (the basics)…

Filament winding is a controlled, automated process in which fiber rovings (carbon fiber, fiberglass, aramids, etc.) are pulled from large spools through a resinous polymeric material, such as epoxy, and wound upon specially designed mandrel tooling. For tubular composite fiber structures, the mandrel is typically a steel or aluminum cylinder that has a carefully machined outer diameter with a precision ground and polished surface to ensure easy extraction of the composite tube. This mandrel tool is held under tension in the filament winding machine and, while the mandrel is spun at precise rates to ensure proper winding, a carriage containing the fiber spools and resin matrix travels back and forth down the length of the mandrel. This process is completely automated and controlled by specifically designed computer winding programs which ensure that the composite material, now a series of laminate plies, is applied accurately in regards to fiber orientation and precise fiber to resin volume for the specific application.

The filament wound structure becomes your product…

Once the composite material is applied, a special non-stick plastic film is wrapped under tension around the part. This film is applied to provide additional compaction to the composite matrix to ensure wet-out and consolidation and is easily removed following the curing process. The mandrel is placed in a computer-controlled oven in which special heating profiles harden the polymeric resin, solidifying the composite material. Following the monitored cure, the wound composite part is then extracted from the mandrel tooling using specialized machinery that protects both the composite and the tooling. The extracted composite is now ready to be processed further to meet all dimensional, aesthetic and other criteria as needed. ACI offers a full range of machining and finishing equipment and processes to meet critical tolerances. At ACI we can mill, drill, grind, bore, turn, cut, sand, bond, seal and paint the raw composite structure to its’ final form per customer specification.

Some specifics…

Advanced Composites, Inc. has four long winding machines that can readily wind up to 30 feet in length and 48 inches in diameter. Filament wound composite tubes can reach ID tolerances of +/- 0.001” dependent on diameter and customer requirements. Additionally, ACI has a fifth winding machine that is 4-axis and ideally suited for quick turnaround prototype runs up to 12 feet in length. All machines have state of the art computer controls to properly apply laminate layers to meet specific design criteria. ACI has a wide selection of mandrel tools that are open to potential customer use for composite tubing. Tooling not currently available can be quickly designed, machined and put online for winding in a matter of days or a few short weeks depending upon complexity.

This short video is an introduction to the filament winding process: