Investigation of the effect of laser technology on the coloring and patterning possibilities in non-see-through tights produced by sock knitting technique

In this thesis, it was investigated the usability of laser technology for obtaining fashionable patterns and designs in non-see-through tights produced by sock knitting technique. For this purpose, the effects of laser treatment on the color obtained at different resolutions (10, 20 and 30 dpi) and pixel times (80, 100 and 120 µs) were investigated before or after dyeing on knitted fabrics made of cotton and polyacrylonitrile yarns. In addition, the color effects that can be obtained by laser treatment on dyed cotton and acrylic fabrics were determined. Color measurements, fastness tests (washing, rubbing, perspiration and light), scanning electron microscopy analysis, FTIR analysis, yellowness index measurement and bursting strength tests were applied to the fabrics. As a result of the studies, it was observed that the the laser treatment led to a lighter color in dyeings if it is applied prior to dyeing on cotton fabrics, and if it is applied after dyeing, it abrades the dye and makes the color lighter. In acrylic fabrics, it was determined that the application of laser treatment prior to dyeing slightly reduced the basic dye uptake, but did not cause a significant effect. In the case of laser application after dyeing, it was determined that it caused some degradation in the color and provided a limited pattern. Within the scope of the thesis, tights samples were produced from 100% cotton yarn on the front side and black-dyed polyester/elastane yarn on the back side, and laser patterning on some parts of the tights was carried out in two different conditions (20 dpi and 80 µs; 20 dpi and 120 µs) according to a selected pattern. When these tights were dyed with blue reactive dye, a pattern containing different shades of the same color was obtained. Similarly, it was seen that it was possible to obtain a pattern when various parts of the tights dyed with reactive or indigo dye were treated with laser under different conditions according to the pattern. In addition, it was determined that a pattern could be obtained by applying regional laser on tights consisting of indigo dyed cotton/acrylic yarn on the front and polyester/elastane yarn on the back. In the light of the findings obtained within the scope of the thesis, it can be said that environmentally friendly clean laser applications can be successfully used to obtain patterning and color effect in socks, and these findings are very important in today's conditions where it is of great importance to produce fashion-brand products with high added value. Key words: Laser, cotton, polyacrylonitrile, reactive dye, basic dye, fastness, ecofriendly