Adapted protective films are essential for the productivity of laser cutting machines. In this article, Abdelrazak Kerbal of Novacel explains why.
Since the beginning of laser cutting technology, the metal sheets preserved by a protective film faced difficulties while being cut. With the latest generation of machines with fiber laser technology, the cutting process was even more complicated. Indeed, because of their wavelength, fiber laser machines could not safely cut the sheets laminated with a standard protective film.
To overcome this difficulty, manufacturers had to burn or to remove the protective films covering the sheets before proceeding with cutting. This practice tends to increase both the production time due to this double cutting pass and the wastage of material due to the sparkles or tools marks.
In addition, the thermal effects of cutting with the flow of assist gas could hinder the smooth running of the process. Indeed, during laser cutting, the film undergoes the heating on the affected zone and tends to soften. This phenomenon, coupled with the diffusion of the high-pressurized cutting gas, can generate bubbles. These bubbles represent areas where the film is no longer sticking to the sheet and are therefore points of weakness in the protection.
Sometimes, dark marks may appear around the cut edges because of the carbon black from the black/white films burnt. In some cases, users must remove non-performing protective films in order to be able to work properly with their machine.
To overcome all these problems and to guarantee a surface protection without interfering with the smooth running of the process, Novacel has been offering protective films specifically designed for laser cutting for over 20 years now.
In fact, Novacel’s range of protective films for laser cutting are developed in partnership with the leading laser cutting machines manufacturers and compatible with all the laser technologies currently used for cutting metals. As the main customers of the company are large metallurgy groups, Novacel products are also widely used by the big names in household appliances, construction and decoration materials, and furniture, which have to present surfaces to the final consumer free from any imperfections, scratches or soiling.
Appropriate Protective Film to Enhance Efficiency and Quality in Laser Cutting
Adapted protective films are essential for the productivity of laser cutting machines. The choice of a protective film depends upon the laser cutting technology used, the protected materials, the sub processes and the industrial segments of application. Thickness of the film, adhesive material used and adhesion level are key parameters for successfully selecting an adapted protective film.
As fibre laser technology continues to advance and as the installation base of systems grows across the globe, there is more on the horizon as manufacturers continue to strengthen its capabilities. Article by LVD.
Machine gantry plays a role in high cutting dynamics.
In the past 10 years, fibre lasers have made a significant impact on the sheet metal fabrication industry. Today, the fibre laser is the most sought-after solid-state laser and is where most laser development work is happening. In global industrial revenues for 2019, sales of fibre lasers far surpassed those of CO2, disc, diode and other lasers. Fibre laser revenues (51 percent) represented about half the total industrial laser revenues in 2019 (Industrial Laser Solutions, January 2020).
No doubt, fibre laser technology has experienced widespread acceptance in the sheet metal cutting sector and a number of factors have powered its growth. Initially best suited for cutting thin sheet metal at high speeds, today the scope and capability of fibre lasers is so much more.
More power and control
Features like an automatic nozzle changer adds to the efficiency of fibre lasers.
High-powered fibre lasers—6-, 8-, 10-kW—have changed the playing field. While high-powered lasers have existed for more than a decade, it is only within the last four years that laser head technology has caught up, allowing manufacturers to expand the scope of materials and thicknesses that can be cut. As a result, a fibre laser cutting machine with 10-kW source can cut 6 mm mild steel at 12,000 mm/min. Even more impressive is the increase in speed when cutting stainless steel and aluminium.
Advancements in cutting head design have made it possible to change the spot size of the laser giving greater flexibility and optimised cutting speeds over a wider variety of material thicknesses. Modern fibre lasers use a variable beam collimator or “zoom focus” cutting head, which allows the focal point to be expanded when cutting thicker materials and decreased for cutting thinner materials. In this way the density of energy, cutting speeds and piercing times are optimised for each material thickness. A significant challenge when cutting thick mild steel is to create a fast and stable piercing process. The machine-controlled focus adjustment (zoom focus) optimises the piercing process by enhancing piercing stability and quality.
High cutting dynamics
Modern cutting head.
With the use of higher power sources and zoom focus technology, cutting speeds have increased dramatically. A fibre laser can achieve up to 5G acceleration. But leveraging more power and high cutting dynamics is only possible in a machine designed for the job. Basically, if the machine can’t maintain the exact position of the tip of the cutting head at maximum speed and acceleration, the cutting process must be slowed down for parts to keep their desired shape.
The machine frame plays a key role in keeping the cutting head in position at maximum speeds and so is critical to a fibre laser’s cutting dynamics. An extremely rigid frame can ‘contain’ the inertia of the high-speed movement of the cutting head and gantry making it possible to take advantage of higher levels of power. In a machine without such a solid structure, the frame is not able to ‘contain’ the deflection of the frame, which can cause problems with accuracy and shorten machine life.
The machine gantry which holds the cutting head carriage should also be a rigid construction to prevent flexing.
A fibre laser cutting machine that combines both an extremely rigid frame and gantry can maintain high acceleration even while cutting.
Reduced maintenance and operating costs are attractive features of fibre laser technology. The wall-plug efficiency (WPE) of the laser source, which is the ratio of power into the source versus power out at the head for cutting, is a core part of these costs. Latest generation fibre laser sources have pushed WPE from 25 percent to over 40 percent. In comparison, the WPE for CO2 lasers is 10 percent and the WPE for disc lasers stands at approximately 25 percent.
The reputation of the Japanese for being hardworking and quality-conscious is not just a cliché. This is proved by the family-run company Daisan Kouki. The job shop processes sheet metal for the automotive industry and relies on technology made in Switzerland. The machines run around the clock—this is the only way to guarantee the highest quality while meeting the ever shorter lead times. We take a glimpse behind the scenes. Article by Stefan Jermann, Bystronic Group.
The ByTrans Extended automation system (on the left) facilitates the loading and unloading of the cutting machines.
Tokyo Central Railway Station. It stands there like an arrow in a taut bow, the rolling legend: the Shinkansen. The interior of the fastest train in the world reflects much of that has made Japan what it is today: a high-tech nation that visitors experience almost like a journey into the future. Everywhere one looks, there is state-of-the-art technology and innovative design. Also inside the Shinkansen. One example of this are the rotating seats, which can be turned against the direction of travel if required.
Travelling to Nagoya with closed eyes, you hardly notice the tremendous speed of more than 320 kilometers per hour. It’s only when you look out of the window that you realize how fast you are actually tearing through the countryside. In addition to technical perfection, the Shinkansen also demonstrates the exeptional service mentality in Japan: Hungry or thirsty travelers need only wait a short while before one of the super-friendly staff comes by to offer snacks.
At the focal point of the automotive industry
The 366 kilometres to Nagoya take virtually no time at all. The journey to the city with a population of 2.5 million, the coal point of the Japanese car industry, takes just one and three-quarter hours. This is where all the major Japanese car manufacturers have their factories: Toyota, Honda, Nissan, Mitsubishi and Mazda. Nagoya generates approximately the same gross domestic product (GDP) as all of Norway. The cargo port and the well-developed land routes facilitate smooth logistics; over the years many suppliers have settled in the vicinity of the renowned car manufacturers. One of the companies that produce here is the family enterprise Daisan Kouki.
The company has been firmly in the family for 70 years. “In the 1960s, Daisan Kouki was a pure family business,” says Noriyuki Wakahara, the managing director of the company, which today has 104 employees. The core business of the company founder, his grandfather-in-law, was trading sheet metal. “One day, when a customer asked why we don’t also process sheet metal, we saw the light,” Wakahara recalls.
In 2004, Daisan Kouki, took its first step into the world of sheet metal processing and purchased a 2 kilowatt laser cutting system. In the years that followed, the factory was continuously expanded – among other things to comply with increasingly strict earthquake safety standards.
“We have always attached great value to reliably meeting even the highest quality requirements and have thus made a good name for ourselves on the industry,” says Wakahara. Most of his customers are active in the automotive sector. The parts that Daisan Kouki manufacturers support the production, above all in creating the production chain.
There has been an increasing demand for laser cutting machines suited for high-mix, low-volume applications. Here’s one development targeted in that area. Article by Trumpf.
In the face of an increasingly volatile market, a growing number of product variants, and shorter delivery times, the picture is clear that the sheet metal industry is getting more complex and lot sizes are falling. This trend, in turn, creates a demand for machines that are suited for small and medium lot sizes and for applications where fast set up times are required.
On the other hand, while investment costs are important, operating costs play an equally—if not even more important—role.
In line with this, Trumpf has launched the TruLaser Cell 5030, an entry-level machine for flexible 2D and 3D laser cut processing with small and medium quantities.
The TruLaser Cell 5030 features magnetic coupling that minimizes mechanical damage to the machine, enabling work to continue quickly and precisely in the event of a collision, without the need for a service technician. Although there are manufacturers who also offer magnetic coupling, the difference is that the optics for the TruLaser Cell 5030 are completely disconnected and offer a much higher degree of freedom and reduce the risk of damage. It also offers the possibility to be disconnected in the Z – direction on top of the X and Y direction.
Cut contour without adaptive feed control.
Investment costs are important, but operating costs play an equally—if not even more important—role. Compared to hybrid and sheet-mover machines, the TruLaser Cell 5030 reduces hourly operating costs by up to 20 percent. The energy efficient and low maintenance TruDisk laser enables significant improvements in energy efficiency during production without compromising on cutting speed and productivity.
The X-Blast Technology has twice the cutting range, and the cutting nozzle can work at a greater distance to the sheet metal, which would result in fewer nozzle collisions and better edge quality as compared to conventional cutting technologies.
It possesses the flexibility that job shops require for cutting mild steel, stainless and aluminum sheets, but also shaped blanks for the automotive and motorcycle industry. The machine requires 30 percent less space, which means precious space in the production hall is made available
In summary, the time to setup a part on the TruLaser Cell 5030 will be shorter compared to a sheet moving system, which translates to additional savings.
Fast, Faster, Fastest
Cut contour with adaptive feed control.
Apart from achieving low-cost production, owners are looking at getting their end product cut within the shortest time. But, apart from just having a quick machine that cuts fast, application is also a contributing factor in achieving fast cutting.
There are many options available to choose from, for instance, if you are cutting thick materials or sheets. The Brightline Fiber enables the user to achieve high-quality cutting results while enjoying the benefits of thin sheet processing with a solid-state laser, most notable at high cutting speeds.
Top cutting quality: You can create high-quality cutting edges in thick sheet with BrightLine fiber function. The optimized kerf makes part removal easier and saves time.
Top part quality: BrightLine fiber combines special optics with flow-optimized BrightLine nozzles and the switchable 2-in-1 cable. The result of this is that you achieve maximum part quality. The smooth cutting edges ensure that your parts do not get caught during removal, saving you a great deal of time.
Work Smart While Cutting Fast
As for owners who are cutting mild steels, which are typically less resistant to corrosion, maintaining the optimum feed rate in cases where the thickness of the material varies within a single sheet, or where the top of the sheet is contaminated with rust or paint would lead to slag formation or interruptions in the cutting process, is no longer an issue.
Active Speed Control enables constant monitoring of the cutting process with a live view through the nozzle. The sensor system observes the kerf, determines the optimal feed, and readjusts if necessary—hundreds of times per second. This minimizes cutting interruptions caused by material differences such as fluctuations in sheet thickness, rust, or coating contaminations. In the event of a potential cutting flaw, Active Speed Control stops the machine, and the TruTops Monitor software immediately informs the operator that intervention is necessary. Active Speed Control also reduces the formation of burrs and dross. The minimized reject rate leads to lowered parts costs and improves process reliability, while only requiring minimum operator involvement with the machine.
Comparison Between Laser Cutting With and Without Feed Control
Cut contour without adaptive feed control
Material bulging can easily happen when flame cutting mild steel without Active Speed Control. This will lead to unclean cuts in certain areas. Ultimately, the feed needed to be stopped entirely, as a cutting flaw had occurred. This results in faulty parts and rejects.
Active Speed Control creates a clean cut, largely without a large amount of spatter or spatter residue. As rust and surface contaminations lead to automatic control and adjustment of the cutting head feed, cutting flaws are prevented effectively.
The World of Sheet Metal Processing
Nothing sums sheet metal laser cutting up more perfectly than a Grand Prix race. The power that the car effectively transfers to the road is important in a race. The same would also apply to laser cutting—only a carefully thought out machine concept, where all components are coordinated with one another, allows the laser and machine to apply the full power to the sheet metal. So how do you win a race? By skipping the pit stops.
Eliminate Pits Stops by Cutting More With Less
With the Highspeed Eco cutting procedure, you can set speed records for nitrogen cutting with solid-state lasers. Depending on the sheet thickness, the sheet throughput is increased by up to 100 percent with consistent laser power, and you can reduce gas consumption by 70 percent.
Its benefits are as follows:
Productivity and feed speed increased by up to 100 percent.
Shortest piercing time and maximum acceleration.
Cutting gas can be reduced by up to 70 percent, while cutting gas pressure can be reduced by up to 60 percent.
Reduced power consumption.
Even on uneven ground.
Resistant to spatter and collisions.
Overall, Highspeed Eco enables extremely smooth and high-quality cutting process with minimal oxidation on the lower edge and minimum burr formation, even in acute angles.
The ByStar Fiber from Bystronic is being enhanced with a 12 kilowatt laser and the new “BeamShaper” function. Besides offering higher speed and an expanded cutting spectrum, a newly designed cutting head ensures consistent cutting quality up to a sheet thickness of 30 millimeters.
To compete for cutting jobs, sheet metal workers need to manufacture quickly, flexibly, and cost-effectively. The best cost per cut part and short delivery times are decisive for achieving good production utilisation. A laser cutting system with its specific components must therefore enable high processing speeds, a reliable cutting process, and low maintenance costs. Those who position themselves this way are awarded jobs and gradually increase productivity. That builds the foundation for growth.
In order to optimally support sheet metal workers amid growing competition, Bystronic is now launching the next level of power in fiber laser cutting: The ByStar Fiber with 12 kilowatts. The high-end fiber laser represents precise Bystronic technology, a stable cutting process up to the highest laser power, and a broad spectrum of applications. It is an enormous technological leap from the three to 10 kilowatt levels, available up until now, to the new 12 kilowatt level.
With the 12 kilowatt laser, the ByStar Fiber’s cutting speeds increase up to 20 percent on average (when laser cutting with nitrogen) compared to the previously available 10 kilowatt laser source. This increases productivity throughout the range of sheet thicknesses from three to 30 millimeters.
Stefan Sanson, Bystronic Product Manager for Laser Cutting explained: “This laser power is of interest to companies that want to achieve higher cutting speeds with material thicknesses starting at three millimeters in order to increase their productivity per unit of time. The result is Swiss quality with lower costs per part.”
New Cutting Head Design For Process Stability
The cutting head is the core element for a stable cutting process and constantly high parts quality. This applies all the more with increasing laser power, which must be brought to the cutting material precisely and reliably. To enable this, Bystronic has consistently continued to develop the ByStar Fiber cutting head.
A slimmer design for the new cutting head increases security in the cutting process. Bystronic is also reducing the number of different components and accommodating important technical functions in the interior of the cutting head. This decreases the danger of collisions with protruding cut parts. The new design also decreases maintenance and operating costs because the integrated technology is better protected from contamination occurring from cutting dust, for example.
Optimal cooling in the cutting head ensures constantly precise cutting performance, particularly for long-lasting cutting operation with high laser power. Bystronic thus protects the lenses and cutting nozzle from high thermal stresses.
High Cutting Quality Up To 30 Millimeters
For sheet metal workers who want to expand their job volumes into the highest material thicknesses, Bystronic has developed a further innovation. The new “BeamShaper” function enables exceptional cutting quality for steel up to a sheet thickness of 30 millimeters. This function can be selected with a new purchase of a 12 kilowatt ByStar Fiber or retrofitted at a later date. “BeamShaper” allows for an ideal adjustment of the laser beam form to greater sheet thicknesses and variable sheet metal qualities. In strengths of 20 to 30 millimeters, the new function thus raises the quality of cutting edges and increases the cutting speed by up to 20 percent.
Automation Optimises The Material Flow
In order to provide an optimal material flow to the high speeds of laser cutting, Bystronic has a broad selection of automation solutions available for the ByStar Fiber. The offer includes loading and unloading systems, sorting solutions, and individually configurable storage systems. Based upon the existing manufacturing environment and available space, a seamlessly integrated automated laser cutting process is developed.
ByTrans Cross is the newest loading and unloading solution on offer from Bystronic. The automation can be flexibly adapted to changing order situations and production rhythms in the laser cutting. Various utilisation scenarios are possible.
As an automation bridge, ByTrans Cross can be integrated between a laser cutting system and material storage in order to direct the material flow. ByTrans Cross can also be used equally well as a stand-alone solution without a storage connection, to provide the laser cutting system with raw sheet metal of differing strengths and materials. In its basic version, ByTrans Cross has two loading carriages that serve as material storage for stand-alone utilisation.
ByTrans Cross becomes even more versatile during cleanup, with the BySort sorting solution, which Bystronic integrates as an add-on solution on request. Thus, users have the option to clear away sorted, completed parts into an attached storage area or to store them in an additional unloading position next to the laser cutting system.
The latter supports the processing of large series, for example, for which individual cut parts need to be sorted separately according to job. A big advantage of BySort is the repeated, precise storage of all parts in one location: A task that is difficult to complete manually, particularly with large cut parts. The parts, exactly positioned on a palette, can be processed more easily during manual and automated subsequent processes, as their location is precisely defined.
Pre-process, cut, transport, and sort sheet metal parts according to orders. All this is carried out by the fully automated Production Line. Bystronic is thus presenting a solution for sheet metal processing in the age of automation and digital networking.
The fully automated Production Line revolves around the ByStar Fiber laser cutting system and integrated automation solutions from Bystronic. The digital Shop Floor Control System integrates the Production Line into the existing sheet metal production environment. This guidance system enables users to set up a manufacturing landscape around the Production Line that permits all sheet metal processing steps to be seamlessly integrated.
The Production Line is capable of processing sheet metal parts both in large series and on a small scale. The integrated laser cutting and automation technologies adapt flexibly to changing order situations while also enabling customised expansion with modular options. The idea behind this manufacturing concept is to combine versatility and productivity. Both are important requirements for industrial sheet metal processing.
Bystronic recently showcased a solution that in the near future will enable the Production Line to be expanded to enable the pre-processing cut parts. ByFlex, an additionally integratable system, drills and deburrs holes, and cuts threads, if required even with countersinks, in sheet metal parts prior to the laser cutting process. The integration of this solution, even before the actual laser cutting process, allows users to make optimum use of secondary processing time within the Production Line.
ByTrans Cross And BySort In The 4020 Format
The objective of automation in the field of laser cutting is to make it possible to process not only large series but also small batch sizes, while maintaining the flexibility that users require to always respond to changing order situations. Bystronic offers the ByTrans Cross automation solution and the BySort module in the 4020 format. This provides users with an extremely versatile extension for the ByStar Fiber 4020 laser cutting system. The ByTrans Cross handles the entire loading and unloading process on the shuttle table of the fibre laser cutting system. This enables metal sheets of up to 4m by 2m to be handled.
As an upgrade module for ByTrans Cross, BySort expands the sorting process for finished cut sheet metal parts with a weight of up to 100 kg. What makes this solution so special: BySort enhances the range of functions in the automated unloading process without requiring the user to expand the footprint of the ByTrans Cross.
Due to the extremely fast throughput times of the ByStar Fiber laser cutting system, with an output of up to 10 kW, automated material loading and unloading is virtually a must, explained Product Manager Alain Meyer. Users can only fully exploit the potential of the fibre laser technology if the material flow is perfectly matched to the laser cutting system’s throughput times.
An additional aspect is the reduction of the machine operators’ workload and the associated increase in process reliability. The loading of raw sheets and the removal of residual grids in the 4020 format is difficult to carry out manually. Here, automation ensures safety and simple workflows. Mr Meyer also emphasised another benefit, “Automation enables users to utilise their laser cutting capacities efficiently around the clock with little manpower, even when faced with high order volumes and short delivery times. The increased autonomy thus also makes it possible to work lightly-manned night shifts.”
Flexibility For Varying Order Situations
The modular design of the ByTrans Cross means that the BySort upgrade can be retrofitted as a sorting solution at any time. For this, Bystronic expands the existing ByTrans Cross system with a bridge on which two sorting heads can operate. Both heads automatically equip themselves with a selection of gripper modules. Depending on the sizes and geometries of the sheet metal parts that are to be processed, the user puts together the matching magazine of grippers.
BySort removes finished parts, sorts them by order, and deposits them on various unloading positions next to the laser cutting system. Mr Meyer explained, “Depending on the production environment, BySort can stack finished cut parts on trolleys, pallets, conveyor belts, or even autonomous transport vehicles.”
This diversity in the unloading process supports sheet metal processing companies that are faced with the challenge of adapting to changing batch sizes. It also helps users to automate the production of small batches so that a variety of downstream processes, such as bending, welding, or painting, can be integrated as easily as possible with laser cutting.
For example, when parts are positioned on a pallet with high precision, they can be processed more easily in the bending step, because the robotics used here or the operator no longer have to check them and adjust them to the correct position. “The precision with which BySort stacks the parts translates into accurate gripping and error-free bending in the next processing step,” said Mr Meyer.