Microscopic study of the surface morphology of CO₂laser-treated cotton and cotton/polyester blended fabric

This paper presents how the morphology of fibers is affected by CO2laser treatment. The change in morphology of fibers induced by a laser affects the physical and mechanical properties of the fabric, such as water absorption, dye uptake, resistance to wrinkles and adhesion to other materials, etc. The morphology of laser-treated fibers was analyzed by scanning electron microscopy (SEM). Samples of cotton twill fabric, cotton/polyester blended twill fabric and cotton knitted fabrics with different yarn counts were studied before and after laser treatment. SEM images reveal different sizes of pores and cracks on the surface of cotton fibers. In the case of cotton/polyester blended twill fabric, the two types of fibers responded differently to laser treatment; the change in cotton fibers was slightly different from the SEM images of 100% cotton twill fabric. The number of pores and cracks on the fiber surface of cotton/polyester fabric was lower than that found in 100% cotton twill fabric. Polyester fibers melt and flow while cotton fibers are encased in resolidified polyester. For 100% cotton knitted fabrics, the thickest yarn with the lowest yarn twist exhibited the largest change when compared with fabrics knitted with lower yarn counts. The degree of change of fiber surface modification was enhanced with an increase of laser processing variables.