Abstract

The final benefits obtained in plastic parts made with the commonly used 3D printing technologies (extrusion, laser sintering, photopolymerizable resin bath, inkjet) depend on the nature of the materials used, and the variables and printing strategies followed for obtaining the parts. In the present study, working with filament extrusion technology, the development of hybrid polymeric structures has been analysed with the purpose of being used as moulds for plastic and composite moulding processes. 3D printing by thermoplastic extrusion enables the use of a wide catalogue of materials, and facilitates the hybridization of the printed parts, choosing different values for variables such as skin thickness, wall thickness, or the pattern and infill percentage. Acting on the values of these variables, it is possible to generate superficial and internal porosity, or obtain cast parts with solid walls that define the geometric details and the surface finish of the final part. The hybridization study was carried out with PC ABS as a thermoplastic printing matrix and catalysed thermosetting resin as a complementary material. The characteristics of the thermosetting resin used in hybridization can be modulated by formulating its composition, to achieve additional features or functionalities in the printed parts, such as greater thermal or mechanical resistance, to modify their conductivity or thermal or electric insulation characteristics.

Abstract

Continuous fiber-reinforced thermoplastic composites are emerging as an efficient structural alternative to traditional thermoset materials, thanks to their recyclability, good impact resistance, and suitability for continuous processing. In this work, a manufacturing system was developed based on the thermoplastic pultrusion of unidirectional polypropylene (PP) and carbon fiber (CF) tapes, followed by hot compression molding. This approach enables the production of structural profiles with high fiber alignment and good consolidation. Experimental characterization included tensile, flexural, and impact tests to assess the structural applicability of the manufactured profiles. The results demonstrate a balanced combination of stiffness, mechanical strength, and impact performance, confirming the potential of this system for functional applications in sectors such as mobility or infrastructure, where lightweight, efficient processing, and sustainability are key requirements.