Glass processing with laser technology
High-speed laser drilling
New radiation sources and improved software have made it possible to increase drilling speed more than tenfold.
Until a few years ago, laser technology was regarded as too exotic, especially in glass finishing: too expensive and too complicated, was the main tenor. Many glass processing companies also saw little customer demand for laser-finished glass panes. Read here why this has changed today and how lasers are now economically viable for use in glass drilling.
"Similar to computer or television technology, laser technology is constantly evolving and the devices are becoming increasingly more powerful and affordable," Jan Ziesak, Sales Manager at supplier Cerion, explains.
"In some areas of glass processing today, drilling, cutting and edge finishing with lasers can be just as economically viable as with conventional technologies. And the flexibility of lasers even offers the added bonus of other options, such as surface finishing," Ziesak sums up the development.
The company from Minden specialised in laser technology for internal glass engraving around 15 years ago, adding surface engraving later on. Cerion is now one of the leading suppliers in these segments.
Stripping and thin layer texturing were added to the portfolio about two years ago. The possibilities for metal coatings, such as Low-E/ITO, are highly interesting in this area.
Firstly, lasers can take on edge stripping, replacing mechanical grinding which is very labour-intensive. In addition, Low-E layers can be invisibly textured with lasers, allowing mobile phone signals to pass through the glass again to provide much better reception quality inside buildings or trains.
Recently, Cerion further developed the laser technology for fast drilling of holes of virtually any size.
Economical laser drilling
While laser systems from this supplier had already been capable of drilling holes previously, they were overall too slow, meaning they could not compete with, for example, water-jet cutting due to the long processing times. But new radiation sources and an improved software have now made it possible to increase the processing speed, i.e. drilling speed, more than tenfold.
"As a rule, we develop the software programs for our laser systems in-house.
Our latest (drilling) process is a real quantum leap, suddenly opening up new areas of application for lasers which were previously not economically viable.
Because the laser can now drill just as fast as it cuts or engraves other materials," Andreas Gross from the Technology and Sales department explains.
The Cerion laser makes a variety of complex hole geometries possible, even oval and rectangular holes, as well as grooves.
Lasers also for jumbo panes
For Cerion, this development step represents the entry point into technical applications. Previously, the c-jet and c-professional systems primarily focused on internal glass engraving and surface machining. These systems can apply 3D images, logos, etc. into glass blocks or flat glass. Surface finishing with the c-vertica for flat glass up to jumbo sizes is another focus point.
Drilling and cutting glass or other materials requires a laser with a horizontal table, as offered by the c-matrix laser system.
"Our laser systems have a modular design and can be used for other applications within a short time.
That means: drilling and cutting special glass and high-speed edge stripping in the morning, applying patterns to façade glass or glass doors in the afternoon.
The automatic module can even cover nights and weekend without requiring personnel," Michael Russo from the Research and Development department says.
"Our flexible systems are suitable for virtually all applications that are required in modern glass processing," Russo continues. For many suppliers, it is already practical today to change to laser technology for drilling and CNC machining. For cutting, lasers are still regarded a supplement, but developments in this area are also progressing fast. Cutting to size with lasers is becoming increasingly cheaper.
Oval drilling cuts are also possible with lasers.
The optical and technical components of lasers have no appreciable wear, as the laser is contactless and operates completely without consumables. Another advantage of lasers is that they allow extremely precise working and are very flexible. Machining glass with a thickness from 0.5 to 25 mm is no problem for drilling and cutting processes.
The much debated aspect of energy consumption has also been put into perspective during recent years, the supplier explains:
A Cerion laser system can be operated with around 3 kWh on average, depending on the laser radiation source used.
"This makes energy consumption a negligible factor in our opinion, outweighed by the many advantages, primarily the high machining quality and the speed," Jan Ziesak says.
In contrast to machining glass mechanically, no cooling liquid is required. This also substantially reduces the maintenance effort and, later on, the cleaning effort for the glass pane. Laser machining is a dry process, almost silent and poses no risk of breakage.
Single-layer safety glass machining possible
The Cerion system can also be used for processing single-layer safety glass. According to the manufacturer, 4-point bending tests have shown that while laser machining has an influence on the stability of the glass type, this can be controlled and reproduced to such an extent that a minimum strength of 90 N/mm² can always be assumed for laser-machined single-layer safety glass. This value corresponds exactly to the strength of single-layer safety glass made from decorative textured glass.
Cerion is the only supplier for machines for surface glass machining which has approval for its technology for machining single-layer safety glass as per DIN EN 12150.
Sand blasting still does not have this approval and is therefore still a legal grey area, as the supplier points out.
More than 250 Cerion laser systems are already in use worldwide. The systems are developed and configured in Minden in Germany.
Many developments are the result of research projects which Cerion carried out together with industry partners, research partners and universities.
At least 35 per cent of the machines delivered to customers are customised designs which are built to individual customer specifications.
Trained employees are a must
The manufacturing period for a laser machine, from order placement to delivery, is often between four and six months. To use a laser as effectively as possible after installation, Cerion also provides intensive training for the system operators over several days.
"It would be terrible if a customer was unable to make use of the full potential of their laser system due to a staff change, for example. In these cases, we provide advice and support at all times, because we want our customers to be 100 per cent satisfied with their lasers," Andreas Gross summarises the company's principles.
Cerion expects further optimisation steps especially in glass processing, as the cost pressure is increasing. Together with the trend for special machining processes, such as stripping, combined with the increasing demand for electrical separation of layers, lasers will continue to gain ground in the glass processing industry in future years.