Development and compressive performance study of 3D printing auxetic structure–Spacer fabric composites

Purpose The utilization of three-dimensional (3D) printing in composite materials reduces constraints and opens new possibilities for the development of protective textiles compared to conventional manufacturing processes. Previous studies have predominantly focused on investigating critical parameters that influence the adhesion quality of 3D printed layers on textile substrates, along with the structural characteristics of two-dimensional (2D) textile substrates. However, 3D fabrics with superior properties have not been extensively explored. This study aims to develop innovative 3 days printing auxetic structure–spacer fabric composites with enhanced protection and comfort. Design/methodology/approach Using an entry-level Fused Deposition Modeling (FDM) printer, polymer materials were directly deposited onto 3D spacer fabrics. A series of printing trials determined the optimal process parameters, after which composites with various tilting angles were fabricated. Their deformation behavior and energy absorption characteristics were then evaluated through systematic compression tests. Findings It is found that Thermoplastic Polyurethane (TPU) is more suitable for composite with spacer fabrics compared to Polylactic Acid (PLA). Optimal printing conditions were identified as a speed of 30–40 mm/s, a preheating temperature of approximately 209 °C and an extrusion temperature between 215 and 220 °C. Additionally, an appropriate Z-axis distance effectively combines the 3D printed components with the fabric while maintaining the comfort of the spacer fabric. Composites with a 45°tilting angle demonstrated the best compressive and energy absorption performance under 80 and 50% strain conditions. Practical implications The composites we fabricated with a single-layer thickness below 9 mm, especially the 45° tilting angle structure is only about 7 mm, meeting dimensional requirements for protective equipment (e.g. helmet liners and protective pads). Additionally, the uniform microporous array on the composites surface enhancing breathability without compromising surface smoothness, and contributing to improve comfort in wearable protective applications. The good performance in compressive strength and energy absorption capacity underscoring its potential in applications requiring efficient energy absorption at low strain, such as protective padding and sportswear components. Social implications The increasing demand for personal safety protection has driven the development of high-performance textile composites. Personal protective equipment must not only provide excellent protective functionality but also ensure comfort and portability. Composites with multifunctional gradually replace traditional textiles by balancing protection, flexibility and wearer comfort. Moreover, flexibility of 3D printing can meet the needs of different markets for customization of high-performance personal protective equipment. Originality/value These findings demonstrate the potential of composite materials in applications requiring high energy absorption at low strain conditions and also reflect the promise of integrating FDM 3D printing technology with spacer fabrics for the design and manufacturing of advanced auxetic materials for personal protective equipment.