Filament winding is a widely used and long-established process that is known for its efficiency in producing rotationally symmetrical components, such as pipes, pressure vessels, or shafts. The most commonly used method in filament winding is a simultaneous winding and impregnating process applying thermoset resins, also known as wet winding. However, there are also methods using pre-impregnated fibers (towpregs) or dry fibers followed by a resin infusion process. Regardless of the method used, it is common for the fibers to slip when they deviate from the so called geodetic path. The geodetic path is the shortest route between two points on a curved surface. On this path, rovings can be laid down stably, i.e. without a resetting force acting on the fiber. To ensure that the fibers remain on a path off the geodesic path even under high fiber tension, a sufficient force must be applied to counteract the force that pushes them back. This force is called the adhesive force. To achieve a stable deposit, it is essential to have a clear understanding of the interaction of adhesion between fiber and surface before the winding process.

To acquire this understanding, a measuring apparatus was developed and implemented as part of a publicly funded project. The apparatus was applied to the real fiber winding process, including the adhesion force transverse to the fiber and the generally curved surface of the wound component. To measure the adhesive force transverse to the longitudinal axis of the fiber, a roving is first stretched over a cylindrical body with a specific force. Then, a tensile force is applied to the cylinder and gradually increased until the fiber starts to slip over the cylindrical surface. The increasing force is recorded with the use of load cells and plotted against the distance traveled. The results show a clear increase in the adhesive force until the fiber detaches. After the fiber detaches, the roving begins to slide over the cylinder, resulting in a distinct stick-slip effect with increasing and decreasing values of the adhesive force until a steady sliding movement is achieved. With the adhesive force determined, the coefficient of friction for each fiber-surface pairing can be calculated by using Howell equation. The data on adhesion behavior obtained in this way can then be used practically to create an adapted winding pattern.