Effect of the alkaline surface modification of the substrate fabric on the peel strength of 3D printed composite fabrics

In the modern fashion industry, 3D printing technologies are increasingly combined with traditional textile fabrics to create innovative 3D garments. Although this integration may not entirely replace traditional clothing manufacturing techniques, it presents opportunities for innovative applications in garment production. In terms of the performance of 3D printed composite fabrics (3D-PCF), adhesion between the 3D printing polymer and the substrate fabric is crucial. However, research on how fabric surface properties influence the adhesion between the substrate fabric and 3D filaments remains limited. Therefore, this study investigates the effects of alkaline surface modifications on the peel strength of substrate fabrics bonded with 3D printing filaments. Alkaline treatment reduces fabric weight, thickness, and tensile strength. Moreover, as both alkaline treatment time and temperature increased, the 3D-PCF peel strength decreased by 30–50%. This is attributed to the reduced fiber diameter and smaller adhesive surface area. Conversely, at NaOH concentrations of 4% and 6%, the increased surface roughness improved peel strength, reaching 15.6 N and 15.9 N, respectively. However, at 8%, surface etching reduced peel strength to 3.7 N. These results demonstrate that optimal alkaline treatment improves surface roughness and the peel strength, while excessive treatment diminishes the adhesive surface area and adhesion strength. Excessive treatment also significantly alters bulk fabric properties, further reducing adhesion. Controlling alkaline concentration to limit bulk changes while increasing surface roughness is an effective strategy to improve 3D-PCF adhesion. Enhanced peel strength through surface modification is expected to prolong the lifespan of 3D-PCF, especially in high-performance applications.