Development trends in laser sheet metal processing
As the UK’s – and arguably one of Europe’s – biggest specialist integrators of laser materials processing, Cyan Tec continuously strives to keep itself informed on the latest application and technology developments, ensuring its solutions are as advanced and competitive as possible.
If the name doesn’t ring a bell, it’s likely because you won’t have seen Cyan Tec at laser trade shows such as Laser World of Photonics or LASYS, simply because it isn’t in the business of making and selling standard machines. Instead, it designs and builds extremely bespoke solutions for industries including automotive, nuclear, plastics, battery, and medical device manufacturing.
Such solutions are so customised and tightly wrapped up in NDAs, that exhibiting them would be in direct contradiction of its raison d’être – giving its customers a competitive edge in their respective markets.
Which is why Cyan Tec was an excellent source to consult on the latest development trends in laser sheet metal processing, despite it not being set to attend the upcoming EuroBLECH sheet metal trade fair in Hanover, Germany, next month.
Bigger sheets, bigger systems
The first development trend highlighted by Tony Jones, Cyan Tec’s managing director, is that sheet metal of increasing size is being used more commonly throughout certain industries, and that laser systems emerging on the market are responding to this.
‘Take flatbed sheet cutting for example, we can see that these types of machines have been increasing in size in recent years,’ he began. ‘For example, both Bystronic and Trumpf – leaders in this field – now offer their ByStar Fiber 8025 and TruLaser 3080 systems respectively, each capable of processing sheets up to 8m long and 2.5m wide. Now, while they have always had the capability to make these XXL format flatbed cutters, the demand won’t have been there previously to justify making them. So the fact that these systems are now becoming available shows there’s definitely an uptick in the number of requests for larger sheets.’
However, as previously stated, Cyan Tec is in the business of making advanced bespoke solutions, and so has been able to respond to the more extreme end of this demand for increasing sheet size.
‘We recently completed a system for the construction industry capable of processing sheets 12m long and 4m wide,’ said Jones. ‘Now while these types of projects don’t come along often, we’re definitely seeing an increase in their frequency.’
Cyan Tec has developed a bespoke flatbed solution for processing extra-large steel sheets: 12m long and 4m wide. (Image: Cyan Tec)
Part of the reason for this, he explained, could be that not only has sheet metal material decreased in cost over the past decade or so, but the forming technologies for producing larger sheets – such as hydroforming and servo-driven press systems – have progressed considerably in terms of their capability.
‘I’d say it was around six or seven years ago that we started to see larger sizes of sheet metal becoming available, and I imagine this has taken a few years to trickle down to the structural architects that actually incorporate them in their designs,’ Jones continued, citing that the construction and shipbuilding industries are good examples of where a lot of these enquires for larger sheets are coming from.
‘Traditionally in shipbuilding you would have had a hull made of say 200 sheets of metal, this can now be done using 20 much larger sheets,’ he said. ‘The advantage of this is that not only are less parts required, but shorter durations of skilled welding labour (which itself is becoming increasingly scarce) are required to join these sheets together. Similarly, in the construction industry, more steel buildings are going up in prefabricated “flat pack” formats, for example at distribution parks. There is no longer as much need for big machines pouring lots of concrete under the foundations anymore, or for using concrete pillars and lots of brick work. These prefab buildings – big steel structures with lots of metal composite cladding on the outside – can be put up quickly and efficiently, and for far less expense than traditional building methods/materials. So I think between industries such as these, that’s why we’re seeing demand for bigger sheet metal cutting machines emerging.’
Variable beams for awkward materials
Another development in sheet metal processing is the introduction of laser sources with variable beam modes, according to Jones.
‘Quite a lot of laser companies are now pushing this technology,’ he said. ‘Everyone has their own name for it – BrightLine, VariMODE, AMB, Corona, ARM, Locus Beam Control etc – but essentially it allows you to push different spots sizes down a single fibre to produce a beam shape with an inner and outer core, each of which you can adjust the intensity of. This has proven to be very useful for laser cutting, as it allows us to pierce through thick materials with a very small spot size – using the inner core – and then slowly open that up by putting power into the outer core to get a decent kerf width. So for us it’s been quite useful for cutting not only thick materials, but also awkward materials that can’t be cut as easily as others, such as mild steels. This has definitely opened up some new applications. Again, to use the construction industry as an example, with them trying to go for increasingly flat-pack, modular builds, they want to produce steel structures that can be slotted and bolted together – rather than needing lots of welders on site. Part of this involves cutting slots into section beams, which are typically made of quite thick cruddy material that isn’t very nice to cut. So here they can use the small inner spot to get that initial pierce through and then put more power into the outer core to complete the rest of the cut, and so this is making this type of application easier.’
Robotics are frequently included as part of Cyan Tec’s automated sheet metal processing solutions. (Image: Cyan Tec)
Jones added that not only is the construction industry looking to use lasers like this to produce modular steel structures that can be delivered to the site and erected rapidly, but they are even showing interest in performing some of the cutting on-site. ‘At recent construction seminars I’ve seen them wanting to do everything on location, which would involve delivering a laser system in the back of a lorry and doing everything there and then. Now I don’t know whether this will take off at all, but it’s one of the topics I’m seeing discussed more and more.’
Of course, a development trend that’s hard to ignore in sheet metal processing is that not only are laser sources becoming more innovative, but also more powerful – systems up to 20kW+ are now available.
‘These systems enable higher productivity when cutting sheets all the way up to 50mm in thickness, however I can’t see this becoming extremely popular in the sheet metal processing industry due to most of the jobs being doable with a sub-10kW laser,’ said Jones. ‘Yes, each part might take 20 seconds longer to cut, but at the end of the day there’s a limit to how quickly you can load and unload sheet metal from a machine. If there’s very, very high-volume production of thicker sheets required, then these high-power systems will certainly find their place. However, in the meantime, most mass sheet metal production is generally done with much thinner sheets that require lower powers to cut anyway.’
One thing that’s certainly happening though as a result of this power creep, according to Jones, is that ‘medium’ power lasers (those around 8-12kW) are becoming available for less cost, which is of course having a beneficial impact on the user.
‘Those who need an 8kW laser can now likely afford a 12kW laser for not much more investment, which will give them not only faster cuts, but offer them more flexibility down the line should they need to process thicker materials,’ said Jones. ‘For us – being on the more bespoke side of the laser business – where we have had the occasional application where 10kW+ powers are required – having the price of such powers having come down in recent years has certainly been of great benefit.’
But it’s not just the laser sources themselves increasing in power and coming down in price, Jones continued. ‘The other development that’s really helped us is the availability of much higher power optics – the process heads we’re using for cutting,’ he said. ‘So around 10 years ago, while 10kW+ lasers were available, the most we could really wield was 6kW as that was the highest level of cutting optic we could get. Now we’re seeing cutting heads from various suppliers that are going up to 15-16kW as more the norm now. So where we do need to cut very thick sheets, this is becoming much easier now due to the increased availability of these higher-power optics.’
As an integrator Cyan Tec brings together components from a range of providers, such as this cutting head from Precitec, to build bespoke sheet metal processing solutions for its customers. (Image: Cyan Tec)
In addition to being able to wield higher powers, cutting heads are also getting a lot smarter, which for Cyan Tec as an integrator enhances the level of automation it can offer as part of its bespoke solutions.
‘This is particularly good as it enables us to use robotics more when designing systems,’ said Jones. ‘The reason for this is that we’ve found that while robots are very repeatable, they aren’t particularly accurate. For example, if I told a robot to go 103mm left and 6mm up, it might go 102.5mm left and 5.5mm up, just because of how many elements are involved in its motion. But what’s happening now is that with advancing vision and optical sensing technology, laser optics are becoming more intelligent. So now if we direct a laser head to cut a part, it can now be positioned approximately next to the part, and then automatically adjust and align the beam paths to process it with the required accuracy. This means we can increasingly use robots that are not necessarily accurate themselves. So that’s certainly a development that’s had a big impact on us.’
The final trend shared by Jones was that, as customers have become more aware of the capabilities of laser technology, they are now looking for laser processing systems that offer more than one type of application.
‘What we’re seeing is demand for more flexibility: systems that can weld, clean, and mark as well as cut – rather than those offering just one process,’ he said, citing battery manufacturing as an example of where this demand is seen – where copper/aluminium components cut from sheet metal must then be cleaned, welded and marked.
‘This offers a number of advantages,’ he continued. ‘Firstly, having single systems performing multiple applications takes up a lot less floor space on the factory floor and requires a lot less capital investment. Secondly, by buying say two or three of these flexible laser cells and transporting parts between them, rather than having a single production line with multiple machines along it, customers make themselves much less vulnerable to stoppages. If a fault occurs on a continuous production line, the rest of the line ceases to operate. With two or three of these flexible laser cells, each offering multiple applications, the likelihood of production ceasing entirely is minimised, as any application that faults could be easily carried out on another machine. In addition, with the increasing advancement of automated guided vehicles (AGVs), it is now possible to transport parts between laser cells with increasing levels of autonomy, and so this modular approach is becoming just as easily automatable as conventional production lines.’
A fibre laser based sheet metal cutting application developed by Cyan Tec. (Image: Cyan Tec)
In terms of the laser sources used in such flexible cells, Jones explained that while the vast majority of the processes can be carried out using a single 1,064nm fibre laser source with interchangeable processing heads, in certain applications – again, using battery manufacturing as an example – there may be other sources better suited to the job.
‘Blue diode lasers and green disk lasers, which have emerged over the past fours years or so, are excelling in certain applications involving reflective metals such as copper and aluminium. Therefore, if the customer wants them and is happy to pay the premium for these additional sources, they can of course be integrated alongside a fibre source in these flexible laser cells,’ said Jones. ‘These sources are quite specialised however, and so won’t be used for much else other than applications involving copper/aluminium. Therefore, if these materials only make up a small portion of what a manufacturer is required to process, then they are likely better off sticking with fibre lasers, which can process these materials – arguably not quite as efficiently – as well as other materials such as steels and carbon composites, etc.’