Comparative Analysis of Towpreg Winding and Wet Filament Winding: The Role of Carbon Nanotubes

ABSTRACT This study comparatively evaluates wet filament winding and towpreg winding techniques, focusing on multi‐walled carbon nanotubes (MWCNTs)' influence on filament‐wound tube composites' mechanical performance. Building on optimized towpreg parameters, it investigates MWCNTs' role in enhancing structural properties. Four composite systems were fabricated using carbon fibers and epoxy resins: a commercial resin, an optimized blend, and two MWCNTs‐reinforced variants (0.1 and 0.5 phr). Mechanical characterization covered transverse tensile strength, interlaminar shear strength (ILSS), pipe stiffness, and energy absorption. Towpreg winding significantly improved transverse tensile strength (45.3%), strain (109.0%), and ILSS (47.3%) versus wet winding. Adding 0.1 phr MWCNTs further enhanced performance, increasing transverse tensile strength (+60.5%), strain (+113.6%), and ILSS (+51%) versus wet‐wound baseline. While 0.1 phr MWCNTs provided optimal enhancement, higher CNT loading (0.5 phr) led to increased brittleness and reduced energy absorption, clarifying this optimization trend. Helical‐wound tubes with 0.1 phr MWCNTs also showed a 53.2% increase in pipe stiffness. SEM revealed improved fiber–matrix adhesion and reduced void content in CNT‐reinforced towpreg specimens. Crushing tests confirmed towpreg‐wound composites had higher total and specific energy absorption than wet‐wound counterparts. Overall, CNT‐reinforced towpreg winding offers a scalable, effective route for producing lightweight composites with superior strength, stiffness, and reliability for demanding applications (e.g., aerospace, automotive, pressure vessels).