It’s widely considered at this point that fibre lasers are supreme in the manufacturing industry— greater power, speed, and no need for laser gases, higher electrical efficiencies and less maintenance requirements are some of the most discussed reasons that job shops are investing in new fibres, most replacing their CO2 lasers for fibre ones.
However, these factors aren’t the only things to consider for the job shop considering new machines. For the fabricator just getting into laser, or those who have only used CO2 in the past, here’s the guide you need to the differences between CO2 and fibre lasers, from the technology and its expenses to the results you can expect in your product.
CO2 and fibre lasers’ big difference comes from their respective methods of generating the laser. CO2 lasers operate through exciting the carbon dioxide molecules in a gas, which is the lasing medium that delivers the beam that cuts your material. It operates at a frequency of 10.6 microns (µm) which is far-infrared. Meanwhile, fiber lasers generate the laser through using ytterbium crystals as a medium (in a solid – glass) within optical fibres. These crystals are “pumped” using powerful laser diodes and the laser beam is emitted as a near-infrared beam of light to cut your material, typically operating at 1.08 µm.
Fibre lasers are generally considered to be faster than CO2 lasers, due to several factors. Powerful lasers allow for thicker materials to be cut at a faster pace—while there are many power levels available for both fibre and CO2, high-powered fibre lasers are less expensive than their CO2 counterparts, and therefore more economical to purchase.
In materials like aluminium and copper, the speed increase is also due to the better absorption of the laser.
The shorter wavelength is to thank for this, with some materials reflecting most of a CO2’s beam rather than absorbing it and allowing itself to be cut. Non-ferrous metal like copper or brass just aren’t able to be cut economically by a CO2 laser, taking longer and wasting power. A job shop primarily dealing in these sorts of materials should absolutely go with fibre over CO2.
For their part, CO2 lasers work very well cutting mild steel and organic materials like acrylic, paper, timber and cardboard. Laser cutters work with these materials in a number of industries for a great number of purposes, such as cutting out cardboard boxes to be folded and used as packaging or storage. CO2 lasers can work just as effectively as a fibre laser at thinner material thicknesses, and will generally produce a superior, smoother cut and with greater capacity for detail in these cases.
The other downside for fibre lasers is that the cut on a fibre can be of a marginally lower quality for stainless and aluminium, resulting in microburrs that may require removal. This extra processing cost impacts the fibre’s time advantage. So for job shops working with materials cuttable on both types of lasers, it’s worth reconsidering whether much time will be saved, or if a noticeable drop in cut quality will impact your productivity rate.
There is a much shorter maintenance cycle for CO2 lasers; the optical components placed inside the oscillator must be cleaned and replaced periodically in order for the machine to work at its best. CO2 lasers typically operate in a vacuum and require gas circulation so there are many mechanical components compared to a fibre. In comparison, fibre lasers can have better longevity and maintenance performance, as their oscillators are isolated from outside factors. Their maintenance cycle is placed at roughly 20,000 hours to a CO2 laser’s 4000 hours.
Naturally, different lasers come with different expenses depending on the machine, even putting aside its generation method. CO2 lasers aren’t nearly as energy-efficient as fibres, generally operating at only 10% efficiency to fibre’s 30%. This means that you’ll be consuming far more electrical power, and paying a lot more. Additional regular costs include the consumed gases and maintenance of the laser’s optical components, expenses not attached to fibre lasers.
Every job shop has different requirements when purchasing a laser, and so there’s no universal answer for the question of which kind is overall the best. The real question needs to be whether a laser suits your needs—is it financially feasible you to not only purchase a CO2 laser, but also pay for its expenses? Are your materials better suited for being cut on one or the other? Can you ignore imperfect cuts, or will you need to allow for secondary processes? These are questions one needs to ask themselves when finding the right machine for their job shop, and we recommend thinking carefully about the answers before committing to any one laser.
