Rapid response textile dyeing: a laser-enabled manufacturing process

Global initiatives and legal frameworks to achieve net-zero carbon emissions will require the development of manufacturing processes significantly different from current commercial methods. The efficiency and fine control of laser-material interactions have proven themselves as disruptive manufacturing technologies that are ideally suited to replace conventional thermal processes. Conventional textile dyeing is known to be resource-intensive, relying on slow-acting thermal dye-fixation processes. These are inherently inefficient as they indirectly heat the material's surface through steam chambers or boiling vats to chemically fixate the dye onto the fabric resulting in large lag system responses. The typical system response time for these manufacturing processes is minutes, which equates to a work-in-progress of hundreds of linear metres of product. This paper presents a method of directly heating the textile surface with a Continuous Wave CO₂ laser in combination with existing commercially available Polyamide textiles and Nylosan Acid Dye. Results from this new process show that the essential industrial quality control standards for colour fastness and mechanical properties are maintained. The key finding discussed in this paper is that using a laser source to provide a direct and rapid heating mechanism at the site of dye fixation enables the implementation of a fast response system. The heating control of the laser is effectively instantaneous, at <100 µs, resulting in control responses that affect less than one linear metre of material. The results presented here represent a product family with annual manufacturing volumes of 1.5 billion meters of textile, creating potential for significant improvements to manufacturing.