Unlike filament winding, which requires a comparatively minimal level of human involvement, lay-up manufacturing involves manually stacking layers of resin-impregnated roving cloth, usually of fiberglass or carbon weave, in an open mold, and compressing them to form a solid composite product. Depending on the application, a mold or other tooling can be used to form the outer profile, while a technician can utilize various instruments such as squeegees and rollers to force the layers together and to impregnate additional resin throughout the stack. Further consolidating forces, such as vacuum bagging or mated molds, can add extra compression if the application warrants it. After the desired geometry has been formed, the composite is placed in an oven to cure.

Flexibility in forming composite structures.

The lay-up manufacturing systems allows for a high degree of craft and technical virtuosity on the part of a composites technician. A skilled technician can create complex composite structures that would be much more difficult via other production technologies. Additionally, the technician can manually orient the fiber arrangement for optimal strength and durability. Because of its labor-intensive nature, however, lay-up is primarily suited to low-volume runs or the production of specialty composite items that would be prohibitively difficult or low-volume for filament winding or compression molding techniques.

Wide-ranging potential for diverse composites applications..

Using the lay-up system, ACI has produced custom composite products from fiberglass, carbon fiber and aramid for everything from communications structures to defense armaments and ballistics applications.