Comparative investigation of digital printing fastnesses of knitted fabrics with different texture structures produced from recycled filament yarns

The natural resources of our world are gradually diminishing, and environmental pollution is rapidly increasing. Soil, water, and air pollution have reached critical levels. In order to prevent this situation, recycling and recovery efforts are being intensively carried out in some developed countries. Numerous studies have highlighted the importance of recycling. In this research, the fastness properties of knitted fabrics produced from recycled polyester yarns and cationic polyester yarns, colored using digital printing techniques, were comparatively examined. In our study, the fastness performances of recycled polyester yarns and cationic polyester yarns in the textile sector were investigated by utilizing the advantages of digital printing technology, such as lower ink consumption and superior print quality. In this context, digital printing was performed with Kyocera KJ4B and Epson I3200 print heads at three different resolutions (600 DPI, 1200 DPI, and 2400 DPI). Two different sublimation disperse inks, Sun Chemical and Papijet, were applied to the fabric using Reggiani and Saitu printing machines. Patterns were directly printed onto the fabric using the Sun Chemical ink on the Reggiani machine. Patterns were printed onto transfer paper using Papijet ink on the Saitu machine, and the patterns were transferred to the fabric using a Lemaire brand transfer machine. Warp-knitted and weft-knitted fabrics with tricot satin texture, plush, and quilted structures were produced with both types of yarn. After applying standard finishing processes, the fabrics were colored using digital printing. The fabrics were then subjected to tests for color fastness against weather conditions, color fastness against light, color fastness against washing, color fastness against perspiration, color fastness against dry and wet rubbing, and the Martindale abrasion test based on appearance change evaluation methods. Different fastness results were obtained depending on the machine and ink brands. It was observed that in the digital printing performed with the Saitu printing machine, recycled polyester yarns exhibited higher color fastness against weather conditions and light, while in the printing performed with the Reggiani machine, these fastness values were higher in cationic polyester yarns. There was no significant difference in the appearance change after abrasion between recycled and cationic yarns. In the coloring performed with both the Saitu and Reggiani printing machines, it was observed that the color fastness against perspiration and rubbing was better in recycled polyester.