Lasers – Cutting Through The Choices

There is little doubt that lasers have become a firmly established production tool for cutting within many industries and applications. Choosing the correct laser cutter however can seem like a daunting task, especially for those planning to use the technology for the first time. In addition, even although lasers have been mainstream for many years, there are still issues with incorrect perceptions and assumptions surrounding the technology.

In this article, TLM Laser’s Andy Toms discusses the different laser types, applications and materials, reinforcing the fact that there is no “one size fits all” approach to laser cutting.


 
Even in our technologically enlightened age, it is still possible to hear the phrase “a laser is just a laser – right?” Whilst the term laser does apply to all variants, the differences between types of lasers, their capabilities and how and where they are applied are vast, requiring careful consideration by prospective purchasers.

Laser cutting systems can be found in areas as diverse as school technology laboratories and high volume, state of the art manufacturing sites. The lasers used at these extremes of the application range are very different, as are the materials that they are likely to be expected to process. For those who have been cutting wood, fabrics or plastic on a small desktop flatbed laser system, it is more than just a leap of faith to decide to move into metal cutting, there is a subsequent leap in technology and cost.

Material types and section will influence the choice of laser for metal cutting

Today, the two main technology choices for cutting metal are CO2 or Fiber lasers. The decision on which to select will be based upon a number of factors, including the types of metal to be cut and material thickness. A further consideration however, is the type of work to be undertaken by the laser. For example, sub-contractors and job shops need high levels of flexibility, due to the potentially wide range of products, and material thicknesses they are likely to encounter, where as an OEM may have a well defined range of regular products of similar material and section, at higher volumes, therefore requiring a more focused approach.

The differences here mean that in certain instances, the sub-contractor may decide that a CO2 laser, with its capability to cut thicker material, might be better overall. The advantages of the CO2 laser when compared with the Fiber alternative, mainly relate to the cutting speed when processing thicker materials, typically above 8 mm. In these instances, the CO2 machine is faster in a straight line cut and also has the advantage of a smoother surface finish when cutting thicker materials. So, if a sub-contractor is to have just a single laser, and they are being asked to cover a wide range of medium to thick material sections, perhaps a CO2 laser might be their preferred choice. In practice however, a number of sub-contract companies employ both technologies, allowing them to select and take advantage of, the most appropriate laser for each application.

The OEM on the other hand may choose the Fiber laser system, which will deliver higher cutting speeds, especially on thinner materials. Typical estimates show a fiber laser cutting 1 mm thick steel will be approximately 3.5 times faster than an equivalently powered CO2 system. Fiber lasers are also able to process reflective materials without fear of damaging the system, meaning that brass, aluminium and copper, as well as traditional steels and alloys, can be safely cut by the laser. Fiber lasers do not have any moving parts or mirrors etc. therefore they require much less maintenance. They also have significantly higher levels of electrical efficiency, making them much less expensive to run. The IPG Fiber lasers, distributed in the UK and Ireland by TLM Laser, typically use 70% less electrical energy than traditional CO2 alternatives in metal cutting applications.

Small Footprint Does Not Necessarily Mean Small Price

There are some perceptions that there is a correlation between the physical size of the laser system and the cost. Of course, the small desktop laser cutters found in school technology laboratories are relatively inexpensive, but these systems do have their limitations. The concept of footprint and cost however does not apply for the systems used within true manufacturing environments, where it is the technology that drives cost.

IPG’s LaserCube uses Fiber technology to process a wide range of metals cost effectively within a small footprint

For OEM’s or Subcontractors who generally work in thinner sections and / or with multiple alloys and higher-value metals, many of which are only available in smaller sheet sizes, the LaserCube system offers significant benefits. Manufactured by the worlds leading developer and manufacturer of high-performance fiber lasers IPG, LaserCube is a compact flat bed cutter and is the ideal cutting tool for metals, including mild steel, stainless steel, aluminium, copper, brass and exotic alloys. Ideally suited to smaller part sizes, prototypes and smaller production runs, the LaserCube provides the most cost-effective capacity addition and lowest cost of ownership of any professional laser cutter.

On thin sheet sections, LaserCube’s Fiber laser source performs much more efficiently than high power CO2 lasers that can become unstable when operating at the lower power settings needed to process these thinner sections. Here the Fiber laser will provide the optimum solution, and for materials that are only available in smaller sheet sizes, IPG’s LaserCube definitely comes into its own. The 1,250 mm cutting bed of the LaserCube is the perfect size for cost effective material processing. The system is also available in a wide range of different power configurations, allowing users to select the power they need, from 500 W to 4000 W. By offering such a broad range of options, users are able to select the exact cutting solution required.

As we can see, there are many factors which will influence the choice of laser and system for metal cutting, and as the brief summary within this article demonstrates, there is no “one size fits all” solution and costs are definitely influenced by laser technology and power, and not by the size of the system.