FEATURE: CO2


optimising Synrad lasers for different materials and processes, and that the biggest driver is increasing throughput, as well as requests for processing larger fields of view or larger materials. She said there are several opportunities to replace manual or contact-based processes, whether that’s replacing ink with laser marking or blades with laser cutting. Novanta’s CO2 laser portfolio ranges


from the 5W Synrad 32-1 with integrated RF for marking, to the Synrad i401 with 400W average power for high-speed cutting and drilling. In addition to Synrad


lasers, Novanta also provides CO2 laser sub-assemblies that include Cambridge Technology scanning optics. Hill said: ‘In addition to defining the right peak power or wavelength for a given application, we’re focusing R&D efforts on optimising the entire beam delivery sub-assembly.’ Trotec’s Fazeny said that, in the low-


power CO2 field, the biggest push forward in the last decade has been to make the sealed technology very reliable. All power levels less than 1kW are typically sealed lasers. They are shipped with a gas fill, meaning there are no running costs, as is


LASERS


the case with fast-flow CO2 lasers, which have high gas consumption. The first generation of sealed metal


lasers have lifetime issues because their gas mix deteriorates slowly, which means power is lost over time – it is a slow drop, Fazeny explained, and typically the laser requires a gas refill after a few years. This has now improved with the advent of the ceramic core resonator, as opposed to the traditional metal resonator. The O-rings in a metal resonator are a weak point that can fail and leak gas over time. Also, there is interference from metal particles, which


LASER PRAYERS ANSWERED FOR TIBETAN STONE CARVING


“This work would open up fibre


delivery for CO2 laser systems, which at the moment isn’t possible”


collect on the optics, making the resonator mirrors blind after a number of years. ‘At Trotec we are now using the ceramic


core lasers from Iradion in the US,’ Fazeny said. ‘There is no metal inside the resonator, even the electrodes are external. This overcomes the lifetime issue of the metal core resonator; Iradion has brought the sealed CO2


lasers to perfection. A mani stone engraved by a Luxinar CO2 laser


Buddhists practice the ancient tradition of mani stone carving in Tibet, using hammer and chisel to inscribe mantras or art into stone, traditionally the six-syllable mantra of Avalokiteshvara, Om mani padme hum. Now, stone carvers in the


Yushu area are turning to lasers to do the engraving. Chinese laser


provider CKLaser began investigating using CO2 lasers to engrave stone when it approached Luxinar’s China office in 2012. Luxinar makes CO2 lasers, and CKLaser wanted to use the laser source as an alternative to mechanical processing. The traditional method


is to work by hand, but in the last decade mechanical tools, such as small electric drills and grinders, have been used to produce larger volumes of the carved slabs. The laser speeds up this process, with the advantage of no tool wear, no need to pre-line or outline the slabs, and the ability to inscribe precise designs and patterns. ‘Characters are carved


by scanning the laser beam across the stone with a galvo scanner,’ Dr Louise May, senior applications engineer at Luxinar, said. ‘Depth can be controlled by adjusting the intensity of the beam as it passes across the substrate to produce 3D effects.’


WWW.LASERSYSTEMSEUROPE.COM | @LASERSYSTEMSMAG May added the effect


does depend on the type and composition of the stone, with the process working better with some stones than others. ‘Laser- induced localised heating can cause vitrification of certain minerals in the rock, resulting in poor engraving with a glass- like appearance,’ she said. However, if these glass- forming elements are not present, there is material removal to produce a deep engraving effect. Initial demand from CKLaser was for Luxinar’s SR 25i and SCX 35 sealed CO2 lasers – 250 and 350W respectively – but Luxinar now also has demand for its 450W OEM 45iX laser source.


There’s no need for any refill anymore.’ In addition, the ceramic resonator has 75 per cent less thermal expansion than a metal body, Fazeny noted. Therefore, during the first 10 minutes of operation there is much less power, mode and pointing fluctuation. Also, the Iradion CO2 lasers are driven by


RF power and use a single-chip design. The RF driver uses the same power transistors used for mobile communication base stations, which are simpler and much more reliable. ‘The chance of failure is definitely less,’ Fazeny remarked. In terms of price, CO2 lasers are


comparable to fibre lasers, Fazeny continued. ‘Fibre laser price has dropped dramatically over the last 10 years, but it settled somewhere in the range of the CO2 laser,’ he said. ‘You don’t need to decide by price, you can decide by application.’ Hill noted that Novanta’s order volumes


for Synrad CO2 lasers are higher than ever at the moment, with many customers exceeding pre-pandemic levels. ‘As long as there are materials that need to be marked or cut, we anticipate that we’ll continue to see growth,’ she concluded. l


AUTUMN 2021 LASER SYSTEMS EUROPE 11


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46