Adhesion strength of 3D printed PLA on knitted fabrics and optimizing for improved performance

Abstract

The application fields of 3D printed textile related products depend on the adhesion of the imprint polymers with textiles. Adhesion is the tendency of unlike surfaces to cling one another due to the intermolecular and interatomic interaction of the two surfaces. In this study, effect of textile structure on adhesion strength from a physical form-locking connection and optimization of process parameters for improved adhesion strength of 3D prints on textiles are investigated. The process parameters investigated in this research are extruder nozzle temperature, printing speed and layer thickness of every layup. The fabric structures include knitted fabrics of 1∗1rib, stripe jacquard and different number and directions of tuck knitted fabrics. The prints were produced from poly lactic acid (PLA) using Flash Forge Guider II 3D printer on knitted fabrics. The different printed samples were subjected to a 180° peel test according to the DIN EN ISO 8510-2 test standard of flexible bonded to rigid test specimen assembly for the full detachment of the prints from the fabric. As seen from the result, the fabric structures and the process parameters of 3D prints investigated in this research significantly influences the adhesion force. The further results revealed that the low temperature, high running speed and high thickness of the print layers limits the penetration, passage and attachment or adhesion of melt PLA through the fabric which gives low adhesion strength between the print polymer and the fabric. The surface appearance of the different loop formation of the knitted fabrics influences the adhesion strength of 3D prints on textile. The microscopic analysis revealed that the back of the detached 3D prints from the knitted fabrics contains much more fibers still attached because of the high adhesion strength from rough surface of knitted structures, high temperature, low printing speed and low layer thickness of the print.