Tack measurement of bindered rovings for the dry fiber winding process

Abstract

For the winding of dry (e.g., not impregnated) fibers on convex structures, an adhesive force between surface and roving has to be established. Providing friction is necessary to prevent the roving from slipping. Usually, rovings impregnated or coated with (epoxy-) binder material are used. The investigation of the tack performance of these rovings differs from established studies on pressure-sensitive adhesives and prepregs. It was found that the common probe test is not suitable for bindered rovings. Instead, shear tests were performed on a heated, flat plate with a robotic winding setup. The horizontal force to pull the roving from the plate was measured. Variation of temperature was in focus. Compaction force, pulling speed, and twisting of the roving were also investigated. It could be seen that compaction and thorough heating are the key factors. Due to the small surface, twisting had no significant effect on the tack behavior.

Analysis and characterization of interlaminar tack for different prepreg materials during automated fiber placement

“…However, no useful results about prepreg tack were obtained through the tack measurements. Furthermore, Neunkirchen [ 26 ] developed a novel shear test method to measure the adhesive force between surface and roving.…”