Side-by-side hybrid textiles are an intermediate step for the production of fibre-reinforced
thermoplastic composites. Press moulding these materials combining reinforcing fibre textiles and
thermoplastic matrix textiles or flexible layers is a promising method to produce high-end fibre-
reinforced thermoplastic composites parts with complex geometry at relatively short cycle times
and lower costs. Since most of the established manufacturing methods for fibre-reinforced ther-
moplastic composites can only produce parts with limited complexity, press moulding of hybrid
textiles could broaden the manufacturing capabilities and offer a whole new set of possibilities.
However, the current lack of three-dimensional consolidation model prevents the establishment of
this technology, as appropriate design and process parameters cannot be determined and defect
formation cannot be predicted.
This thesis presents the development of a three-dimensional consolidation model for press
moulding of hybrid textiles. First, a literature review is presented to identify the limits of models
addressing effects relevant for consolidation. A model for the stress response of textile stacks,
which is an effect taking place during consolidation, is validated and a numerical approach to
characterize the model parameters is presented. Then, a novel consolidation model for hybrid
textiles including air entrapment, dissolution and diffusion is developed and validated experimen-
tally using glass reinforcements and polypropylene or polyethylene matrices. Direct measurement
validates the model of Gebart for permeability, a key model parameter, at very high fibre vol-
ume fractions and it is shown that entrapped air significantly influences impregnation. Finally,
the model is extended in three-dimensions with some restrictions by considering a free-form plate
with non-uniform thickness. By adopting a unit-cell approach with three-phase flow, it is possi-
ble to take into account the volume change resulting from matrix flow and impregnation, and by
adopting a homogenization method the computational challenges of a full-scale simulation can
be bypassed. This novel consolidation model provides insights to explain the fiber movement
in non-uniform thickness plates, enables part and process optimization, and paves the way for
high-quality composite part production.