Technical study of the effect of CO2 laser surface engraving on the colour properties of denim fabric

The laser engraving process allows short-time surface designing of patterns with precision, desired variety, size and intensity on a wide range of textile surfaces with minimum damage to the material. Because of this, it is possible that laser engraving applied to textile materials can make the fabric look faded and worn out without the use of any of the chemicals that are usually required in the conventional colour-fading process. In the present study, laser engraving was applied to denim fabric in order to evaluate its effect on some colour-related properties. Two laser process variables, namely, resolution and pixel time, were studied thoroughly. The laser power density was enhanced in response to the increased level of pixel time and resolution. Under the effect of high laser power density, a paler surface appearance was achieved for the denim fabrics with the largely reduced K/S-sum values, indicating that the amount of dye present on the denim fabric was decreased significantly. In addition, a green yellow shade was observed in the denim fabric samples after laser engraving.