The effect of laser technological parameters on the color and structure of denim fabric

Abstract

The effect of laser technological parameters on the color of denim fabric is a topic of research for scientists in various countries. More detailed investigations, which would estimate the effect of several main laser technological parameters on the color, taking into account morphological fabric modifications, have been yet to be performed. Therefore, the aim of this study was to define the effect of laser technological parameters on the color of denim fabric. In the research, denim fabric was used with the following fiber content: 98% cotton and 2% EL, surface density 357 g/m², weave – twill 3/1. The specimens were treated using a CO₂ laser, with changing beam power and motorized drive parameters – the speed and step. Using a spectrophotometer, the change of the fabric surface color, ΔE, and color system, HSB, were determined both before and after laser treatment. Morphological analysis of the fabric was carried out uing a scanning electron microscope. The research showed that the color change, ΔE, of the laser-treated specimens is different in the warp and weft directions. The highest ΔE was reached while changing the beam power. The largest effect on the change of color hue, H, and color saturation, S, amongst all tested laser technological parameters was found for laser power. Color brightness, B, was mostly affected by laser step size, when laser energy density is ∼6 mJ/cm².