Lasers have been used to effectively cut metal since 1965; however, it wasn’t until 35 years later that they really started to take off. Charles Corner, managing director of sheet metalwork manufacturer Fresh Metal, discusses the evolution of the laser and how advancements have had a significant impact on the industry.
Lasers were first used to cut materials in 1965, and over the next 10 years, British engineers used assist gases to cut metal using laser. One of the first machines that we introduced at Fresh Metal was a CO2 hybrid laser machine.
The hybrid element allowed the cutting head to move in one direction and the sheet of metal to move in the other. CO2 lasers produced the laser beam using a mixture of gases in a chamber, and the gas was stimulated with electrical charges. The CO2 machine would take around 10 to 15 minutes to reach the right energy level to be able to start cutting – a stark contrast from the laser machines of today.
At this high-energy point, a 20mm beam of laser light would stream out. This light was reflected through water-cooled mirrors all the way to the cutting head, here special lenses focused the light to a tiny focal point 0.2 mm in diameter. Just like using a magnifying glass to focus the sun’s light (setting fire to paper I remember!).
This fine beam of light combined with a cutting gas (oxygen) or an inert gas (nitrogen) passed through a nozzle. The oxygen produced an exothermic action, meaning that the oxygen assists the cut, whereas nitrogen produces an endothermic reaction, blowing the melted metal away. The nitrogen also prevented oxidation of the cut edge, and gave what we call a ‘clean cut’.
While CO2 lasers cut metal effectively, they do consume a considerable amount of electricity. They also use many working components such as turbo-blowers to produce the cutting laser light. I remember installing 200 KVA to our first industrial unit, at that time this was only enough to power two laser machines.
Prior to 2000, punching machines were the method of choice. Using multiple punch tools, it would essentially punch shapes and profiles into a sheet of metal. Punch machines were more economical than CO2 lasers, however, the tools became blunt very easily and would be costly to replace.
By 2000, sheet metal cutting was beginning its revolution and lasers were starting to gain traction. Using just one tool – a single focused laser light – and with the main consumables being nozzles and lenses, the costs are much more cost effective when compared to punching due to the no contact feature of the machine.
As well as offering a precise and quick cut, laser machines are much quieter than other machines. Our production manager has threatened to leave if we ever buy a punch machine!
Lasers really took off, quickly outselling punches in the early 2000s. It was these sales successes that fuelled a technology battle between some of the world’s leading machine manufacturers with Japan’s Amada, Germany’s Trumpf and Switzerland’s Bystronic leading the way. Each company competing to meet the demands of the markets and to win the next machine order.
Following this surge in laser cutting machines, we invested in a Japanese Amada with a tower feed automation system – this machine offered two times the cutting power, from 2kw to 4kw. It was at this time when another major development occurred in the industry in the form of flying optic, in which the sheet metal remains stationary in the machine bed and the laser cutting head does all the moving.
The CO2 Amada machine demonstrated a significant jump in speed and thickness, showing big leaps in operational efficiencies and sometimes doubling outputs, giving our company a very welcome commercial advantage and enabling sustained growth.
There are many aspects that make up a good laser cutting machine. Each manufacturer has their own research and development departments, striving to achieve new benefits year after year, but as a buyer of these specialised machines, Germany and Switzerland were definitely leading the way in the industry at this time.
In the meantime, there was a newcomer. Fibre laser was evolving dramatically under everyone’s radar and a revolution was on the cards.
By 2014, just two years after they appeared on the market, fibre lasers were impossible to ignore. In what seemed like an explosion of technology, fibre lasers were suddenly capable of processing 0.6 to 20mm job-shop thickness and the designers had matched the pierce times of CO2 machines, but with the ability to cut much faster. Alongside all this, electric consumption was reduced to a third. In the space of two years, these revolutionary machines had come from niche to mainstream and within the next six months, 80% of manufacturers’ books were filled with orders for fibre laser systems.
Our fibre laser arrived in May of 2014 and completely revolutionised the company. Imagine a machine capable of performing at three times the capacity with a third of the running cost of the previous machine. It was an amazing result for our company.
Fibre lasers are solid state and use diodes to produce laser light. It sends that light down a fibre optic cable straight to the cutting head with the ability to start up and shut down instantly – zero time wasted, zero energy wasted. Thanks to the reduced cutting times, we also experienced a reduction in gas usage, another huge benefit accompanying the fibre lasers.
The revenues from this created an industry giant. This giant, based in Russia, spent years creating a unique laser source. When it finally launched this revolutionary technology, it was leaps and bounds ahead of any other sources on the market and because of this, almost every laser cutting manufacturer began purchasing it to use in their machines. Hundreds of new laser cutting machine manufacturers appeared on the market in a short space of time following this introduction.
The technology advancements in such as short space of time have had a significant impact on the industry. It has enabled manufacturers to not only reduce energy consumption and cut costs, but it has also led to an increase in productivity and better quality output. What does the future hold for cutting metal with light? Light is the fastest thing in the world after all.
Categorised in: Technical articles