Edge quality optimisation for CO2 laser cutting of nylon textiles

Lace fabric is manufactured in large webs typically 3 m wide. Traditionally smaller pieces of lace are separated from the main web using mechanical means. Laser systems have been developed at Loughborough to automatically cut lace using a machine vision guided CO2 laser. Lasers being a non-contact cutting method offer significant advantages for cutting lace over mechanical means. Mechanical methods cause distortion during cutting which limits the possible cutting speed without errors and requires regular blade sharpening. The lace can be cut using either continuous wave (CW) a or pulsed CO2 laser, both laser modes cause thermal damage to the cut edge. The thermal damage is typically in the form of molten material that has re-solidified to form hard edges, these detract from the quality of the finished product. The CO2 laser cutting process has been optimised with the aid of a 3D transient finite difference model. Trials of the modified processing parameters have proved to give a significant improvement in edge quality.