Laser cutting is well established for cutting metals, alloys, and ceramics. However, its application for cutting fibre reinforced polymer composites is constrained due to specific challenges. The distinct optical and thermal properties of the fibres and matrix often lead to excessive thermal damage. Thick-section laser cutting of composites is an especially challenging task. The water jet guided laser (WJGL), employing a hair-thin water jet to guide the laser, has proven successful for such challenging materials. Thermal damage is minimized by effective in-situ cooling of the interaction zone by the water flow.

This work evaluates the feasibility of WJGL cutting glass fiber reinforced polymer (GFRP). A WJGL system, fitted with a 400 W green nanosecond laser, was used to cut 7.5 mm thick GFRP using a multi-pass strategy. Effective cutting speeds of up to 10.1 mm/min were obtained with an average wall taper of 1.91°. Improvements in taper angle were realised via reduced effective cutting speeds (0.81°, 7.5 mm/min). Defects including charring, edge chipping, and matrix discolouration were observed. These results show that while the WJGL can cut thick GFRP with minimal defects, further work is required to enhance the productivity before the technique could be viable for widespread adoption.

Read the full publication here: Water Jet Guided Laser Cutting of Thick Section Glass Fibre Reinforced Polymer