The last possible reason to buy a CO2 laser cutting machine – namely to process thicker materials economically – has been removed, according to Jon Till, joint owner of Accurate Laser Cutting.
Having used laser cutting machines since 1999, Jon Till contends that the demise of CO2 is nigh, with fibre holding numerous advantages over CO2 laser cutting in terms of increased machine availability and productivity, lower running costs and greater versatility.
Till has used laser cutting machines since 1999, when the company he was involved with bought a Bystronic BySprint 3 kW CO2 model, swiftly followed by 4 kW and 4.4 kW versions, and the first 6 kW machine in 2002.
June 2015 saw the introduction of fibre laser cutting with the installation of a 6 kW BySprint Fiber with 4m x 2m capacity at the Oldbury-based Accurate Laser Cutting. A 10 kW ByStar Fiber for processing sheet up to 3m x 1.5m has recently been added in November 2016 – reportedly the first machine of such high power to be installed in the UK.
According to Till, 6 kW is the practical limit for CO2 laser cutting, as higher power would burn the optics. Even power sources below this limit take their toll on the lenses and mirrors in a machine, he noted, leading to frequent downtime to clean them, expensive periodic replacement and production stoppage while maintenance is carried out.
CO2 laser machines can also be difficult to maintain, not only due to the condition of the optics, but also the tendency of the optical path to move out of alignment, necessitating time-consuming correction if quality is to be maintained.
Till also bemoaned the fact that one can spend hours identifying a problem with a CO2 laser cutting machine when quality or speed of cut declines, with the issue possibly relating to control parameters, lenses, mirror alignment or the purity of the assist gas.
A proponent of fibre laser cutting, Till noted that the solid state technology avoids many of these issues by directing the beams down a fibre optic cable, so there’s no wear and tear on conventional optics and the laser beam doesn’t degrade.
Machine running costs can also be significantly lower, as electricity consumption is around 60% less for a fibre machine, and there’s no need to use expensive nitrogen, helium and carbon dioxide as laser assist gases.
Till commented: “Our new 10 kW ByStar Fiber cuts 1mm mild steel at 60 m/min, faster than our old CO2 laser was able to position its head (50 m/min) to start cutting. The speed and hence productivity advantage when processing thinner sheet is around three-times, reducing for thicker materials.
“Clean cutting is also much quicker, where nitrogen rather than oxygen is used as the cutting gas to prevent oxidation of the cut edge. When processing 5mm mild steel, for example, the fibre machine is four-times the speed of our last CO2 machine.”
Regarding productivity, Till suggested that one would be reluctant to leave a CO2 machine running unattended overnight, such is its tendency to drift out of tolerance, whereas he would have no hesitation running a ghost shift with the fibre laser.
He noted that the technology has deskilled operation to the point where on a fibre machine one simply presses a button and the machine starts producing, whereas there is still a lot of black art in operating a CO2 machine.
He concluded: “A fibre laser can cut everything that a CO2 laser can process and very much faster in the case of thinner gauges. It’s also able to tackle a much wider variety of materials – perfect for a subcontracting environment.
“It achieves accurate and repeatable results economically with very little machine downtime, raising production output day and night. In my view, this latest 10kW machine is a game changer in laser cutting machines.”