Technical study of the effect of CO₂laser surface engraving on the colour properties of denim fabric

Abstract

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.

Effect of CO2 laser treatment on cotton surface

“…In addition, the laser power density also enhanced with respect to the increase of resolution and pixel time. Since CO 2 laser would cause thermal degradation to the irradiated materials (Ferrero et al 2002;Kan et al 2010), thus cellulose molecules which suffered from dehydration would have -OH groups oxidised, thereby forming carbonyl group at about 1,590 and 1,750 cm -1 such that the intensity of IR absorbance spectra at this range was increased (Yang and Freeman 1993). It was believed that laser treatment would break down some surface fibres into small oxidised fragments which adhered to the fibre surface.…”

The use of laser in garment manufacturing: an overview

“…The desired degree of fading depends upon the wavelength, power density, and pulse width of the laser beam. The method of marking or fading by laser is more environmental friendly as compared to acid washing or sandblasting (Kan et al 2010). A laser-faded denim sample is shown in the Fig.…”

“…The process is very complex, and often computerised systems are used to drive the laser head (Kan et al 2010;Juciene et al 2013). In spite of the complexity, very precise and clean engravings can be obtained with high rate of production.…”

“…This technique is very accurate and can work fast with good repeatability and reproducibility (Hung et al 2011;Kan et al 2010). …”

“…Laser can help to cut a variety of objects ranging from flexible fabric to rigid and strong metal (Belli et al 2005;Ondogan et al 2005). Laser equipment are becoming widely popular in textile, leather and garment industries due to the advantage of accuracy, efficiency, simplicity and the scope of automation (Kan et al 2010;Lu et al 2010;Sutcliffe et al 2000). For example the conventional cutting tools such as band blades, discs and reciprocating knives suffer from the limitations especially on delicate materials as the cutting force can displace the material, which can lead to inaccurate cutting .…”