Processing models and characterization of thermoplastic composite wound parts

Abstract Squeezing flow was adopted to model the processing of thermoplastic composites in filament winding. It is found that the resin flow is facilitated as a result of the slip condition, thus reducing the process times. An apparatus with a constant dead weight was employed to characterize the rheology of the thermoplastic composite in filament winding. The system is carbon fiber (AS4) reinforced with the polyetherketone‐ketone (PEKK) thermoplastic matrix. It is found that resin flow is dominant in the transverse fiber direction and there is insignificant flow along the fiber direction. An empirical equation of viscosity for AS4/PEKK as a function of temperature was obtained based on the model. For mechanical properties, either in a 4‐point bending test or a short beam shear test, most of the hoop wound rings failed at the inside radius or on the compression side. Insufficiently applied heat and a cold mandrel in the beginning of the winding process may result in low degree of consolidation on the compression side. The average void content of the hoop wound ring is lower than that of the preimpregnated tow because of void compression through resin flow during the winding process.