Menu
Saturday, 22 Luglio 2017
A+ A A-

Precision laser-cutting technique optimized for thick metal sheets

Limo13Using lasers to cut sheet metal is something that has typically been handled in the realm of CO2 and fiber lasers, though this may not be the case for very much longer: Diode lasers are increasingly emerging as the light source of choice for a large number of applications, as can be seen from the BRILAMET research project that has just come to a successful conclusion. There is a great deal of interest surrounding laser cutting, and events related to this topic often draw plenty of publicity. One recently-concluded research project in particular will likely attract even more attention, especially for applications in the sheet-metal industry, namely: the BRILAMET (brilliant high-power diode lasers for metal processing) joint research project, which was carried out between July 2012 and June 2015 as part of the German Federal Ministry of Education and Research program entitled “KMU-Innovativ, Optische Technologien” (“optical technologies in innovative small and medium-sized enterprises”, promotional reference: 13N12282). During this period, the Laser Center at the Münster University of Applied Sciences (LFM) teamed up with the Dortmund-based LIMO Lissotschenko Mikrooptik GmbH to conduct extensive experiments in the area of precision cutting for thick metal sheets. Initially, the project involved the use of a 2.5 kW high-power diode laser (HPDL) that was coupled to industrial CNC machining equipment. LIMO had used special micro-optics to optically connect the HPDL beam source modules. Through an optical fiber, the HPDL beam was then guided to the cutting head, which was also developed by LIMO. LFM and LIMO employed the “Design of Experiments” (DOE) methodology to optimize the cutting process by experimenting with different nozzle geometries and diameters, as well as with other aspects. As the project progressed, the experiments were expanded to include a 4 kW HPDL beam source, which likewise consisted of two laser units coupled together. Among other things, the project showed that although a high-power diode laser operates at a relatively modest brilliance, it is well suitable for the rapid and precise fine cutting of 6-mm thick stainless steel (speed > 2.0 m/min., roughness Rz < 30 µm). “The key ingredient here is not only the asymmetrical laser beam geometry but also the model for predicting machining results, which was developed during the project,” explains Dr. Jens Meinschien, Vice President Innovations Management at LIMO. “By making further laser beam-shaping adjustments, cutting speeds of 2.5 m/min can even be achieved with 4 kW diode lasers.” But the experts at the Dortmund-based company were interested in more than just using HPDL beam sources to optimize high-precision laser cutting processes: “Over the past three years of close cooperation with the laser specialists at the Münster University of Applied Sciences, we have acquired a great deal of additional expertise,” Dr. Meinschien notes in looking back on the successful collaboration. He adds: “We now know how to improve the components and, most importantly, the beam-shaping systems for kW beam sources using an adapted optical, mechanical and thermal design.” LIMO has presented the results of the project at international trade fairs and conferences as well as in trade journals, and the findings have caught the attention of experts throughout the field. The entire topic appears to be somewhat of a never-ending story for LIMO, as the Dortmund-based company is currently pursuing additional laser-cutting research alongside internationally renowned experts as part of the EU “Lashare/Nextcut“ sub-project. Says Dr. Meinschien: “I am very excited to see what kind of additional expertise we can gain from this research collaboration.” 

Leggi tutto...

Cinematic enjoyment with laser brilliance

Limo12The United Nations (UN) has declared 2015 the "International Year of Light and Light-Based Technologies." "Light for Change," the motto accompanying this UN year, particularly applies to laser technology, which is now also taking over movie theaters. Micro-optics and services from LIMO have played a "leading role" in these and other laser projections for years. Both light technology and new laser applications are the focus of the activities and events planned for the current UN year, which will be conducted by the German Physical Society (DPG), located in Bad Honnef, in partnership with the German UNESCO Commission. "During my physics studies, I was fascinated by everything about the scientific field of optics, and this of course ultimately led me to laser technology," says Dr. Oliver Homburg, Director for Advanced Optical Solutions at the Dortmund-based LIMO Lissotschenko Mikrooptik GmbH. "Laser projection is one of the developments we've been closely involved with at LIMO for quite some time, and it is certainly one of the most exciting. " In a sense, the success of this development is also a matter of survival for movie theater operators: According to the industry journal "Electro Optics," many moviegoers have already complained about excessive darkness during 3D film showings. New 3D laser projectors are now expected to provide some relief in this area. Unlike conventional bulb technology, these projectors deliver better brightness, higher contrast and improved brilliance. In addition, the diode laser sources used in the new devices have a significantly longer useful life and are much more energy-efficient. The quality of RGB laser projectors, which are now capable of projecting three-dimensional 4K films with a luminous flux of approximately 60,000 lm or more, depends fully on the micro-optics used. Specifically for the red spectral range, where laser diode bars or mini-bars are used, LIMO offers special FACs and SAC arrays (for independent collimation of both axes) as well as BTS (for beam transformation on free-beam lasers with a symmetrical beam profile, or for fiber coupling). LIMO also performs the installation of its optics. While LIMO micro-optics stand out due to their high performance and quality, they also come at an attractive price thanks to their efficient wafer production. The "monolithic fiber-coupler" is in particularly high demand. Dr. Homburg notes, "A single fiber-coupler can couple the light of a mini-bar with up to 10 emitters into one fiber. To me, that's true cost-efficiency – something that can also be found on our micro-optics for the green and blue spectral ranges." This means that, thanks to LIMO technology, viewing movies in laser brilliance is becoming an affordable pleasure. And that would fit perfectly with the idea behind the “International Year of Light and Light-Based Technologies”. 

Leggi tutto...

Beam tool: a new surface-processing specialist

LIMO11A new “beam tool” developed by LIMO as part of a research project brings to mind the famous marketing slogan “There's always a clever head behind it” from the Frankfurter Allgemeine Zeitung, one of Germany's major daily newspapers. The special feature of this new compact laser head is its zoom function, which delivers a processing flexibility capable of handling an incredibly wide range of surface types. The head measures 148 mm long with a diameter of 50 mm and is enclosed in an aluminum housing. As part of the ALPS project, this laser zoom processing head was developed at the Dortmund-based LIMO Lissotschenko Mikrooptik GmbH as a new beam shaping module for surface processing. Though the prototype is no more than half the size of the typical baton used by relay runners, it converts a continuous output of 1.0 kW (maximum short-time output: 2.5 kW) from glass fiber to a line focus - despite its miniature dimensions. “This is an extremely compact processing head which stands apart mainly thanks to its zoom adjustment feature,” notes dottor. Thomas Mitra, Head of the Micro-optics Development Department. “The new tool can be used to make specific modifications to the line length during processing. This means that the laser beam can be set to trace contours or adapted to fit individual workpieces”. The ability to quickly and easily adjust the zoom during processing decreases the amount of setup time required. This results in greater process flexibility and therefore also enables economical laser processing of workpieces in small batch sizes. Dottor Mitra goes into greater detail for laser experts: “The extremely compact size was made possible by a new optical concept in which two special micro-optics are used to directly handle homogenization and length adjustment. Conventional setups first homogenize beams with micro-optics and then typically require three additional optics to adjust the line length along one axis”. Initially developed for the production of solar cells (wavelength of 808 nm to 1064 nm), this concept could also be used in laser plastic welding to adapt the line width (0.2 mm to 0.6 mm) or length (4 mm to 12 mm) to individual workpieces - without switching the laser or replacing the processing head. According to dottor Mitra, the laser head is particularly beneficial where lasers are used to weld plastics, since it allows even those parts to be welded which have varying widths along the weld seam. Because of its compact and lightweight design, the new beam tool can also be easily mounted on a robot arm or translation stage. Using this concept as a starting point, LIMO is currently working to develop additional beam shaping modules for outputs of 6 kW and 10 kW. Thanks to a motorized zoom adjustment feature, these modules will also be suitable for automated processes and capable of handling larger, freely variable profiles (incl. adjustability on two axes). In addition to plastic welding, this compact technology can also be used in metal hardening and roll cladding.

Leggi tutto...

Beam tool: a new surface-processing specialist

LIMO11A new “beam tool” developed by LIMO as part of a research project brings to mind the famous marketing slogan “There's always a clever head behind it” from the Frankfurter Allgemeine Zeitung, one of Germany's major daily newspapers. The special feature of this new compact laser head is its zoom function, which delivers a processing flexibility capable of handling an incredibly wide range of surface types. The head measures 148 mm long with a diameter of 50 mm and is enclosed in an aluminum housing. As part of the ALPS project, this laser zoom processing head was developed at the Dortmund-based LIMO Lissotschenko Mikrooptik GmbH as a new beam shaping module for surface processing. Though the prototype is no more than half the size of the typical baton used by relay runners, it converts a continuous output of 1.0 kW (maximum short-time output: 2.5 kW) from glass fiber to a line focus - despite its miniature dimensions. “This is an extremely compact processing head which stands apart mainly thanks to its zoom adjustment feature,” notes dottor. Thomas Mitra, Head of the Micro-optics Development Department. “The new tool can be used to make specific modifications to the line length during processing. This means that the laser beam can be set to trace contours or adapted to fit individual workpieces”. The ability to quickly and easily adjust the zoom during processing decreases the amount of setup time required. This results in greater process flexibility and therefore also enables economical laser processing of workpieces in small batch sizes. Dottor Mitra goes into greater detail for laser experts: “The extremely compact size was made possible by a new optical concept in which two special micro-optics are used to directly handle homogenization and length adjustment. Conventional setups first homogenize beams with micro-optics and then typically require three additional optics to adjust the line length along one axis”. Initially developed for the production of solar cells (wavelength of 808 nm to 1064 nm), this concept could also be used in laser plastic welding to adapt the line width (0.2 mm to 0.6 mm) or length (4 mm to 12 mm) to individual workpieces - without switching the laser or replacing the processing head. According to dottor Mitra, the laser head is particularly beneficial where lasers are used to weld plastics, since it allows even those parts to be welded which have varying widths along the weld seam. Because of its compact and lightweight design, the new beam tool can also be easily mounted on a robot arm or translation stage. Using this concept as a starting point, LIMO is currently working to develop additional beam shaping modules for outputs of 6 kW and 10 kW. Thanks to a motorized zoom adjustment feature, these modules will also be suitable for automated processes and capable of handling larger, freely variable profiles (incl. adjustability on two axes). In addition to plastic welding, this compact technology can also be used in metal hardening and roll cladding.

Leggi tutto...

Expanded portfolio with 10 systems

limo10They are small, inconspicuous und transparent: Beam Transformation Systems (BTS) bundle and symmetrise asymmetrical laser beams generated by diode laser sources (bars). With its expanded portfolio of ten BTS, LIMO is now able to offer the largest selection and widest range of these quick-change artists for (almost) any application. Our Beam Transformation Systems turn the very asymmetrical output of a bar laser source into a symmetrical beam”, says Dr. Oliver Homburg, Director for Advanced Optical Solutions at LIMO Lissotschenko Mikrooptik GmbH in Dortmund. “Users need a BTS to create a free laser beam or to feed the beam into a round fiber. Our new range of BTS, which has been expanded to 10 systems, is surely the largest standard portfolio available anywhere in the world”. The 10 quick-change artists from Dortmund with pitches of 200, 400 and 500 µm are suitable for converting the light from standard diode laser bars and mini bars. BTS are available for wavelengths from 600 to 1600 nm. High beam quality is assured thanks to excellent residual divergence that ranges from 13 to under 5.0 mrad. To achieve the best possible performance for a specific application, LIMO uses 4 Fast Axis Collimators (FAC160, FAC286, FAC365 und FAC410) that have been optimized for short focal lengths. The effectiveness of these high-performance optics systems is critically dependent on how they are mounted, which is why LIMO offers its customers a special service. “We offer automated BTS assembly”, explains Dr. Homburg. “This is an important addition to LIMO’s newly expanded BTS portfolio. Please get in touch with us if there are any questions about your specific applications. We are sure that we have a made-to-measure solution using the elements of our enlarged standard portfolio.”

Leggi tutto...

LIMO boasts world's fastest laser scanning system

LIMO6A lightning-fast laser storm has developed in Dortmund and is poised to brighten the spirits of solar power system manufacturers with an enormous boost in productivity. The storm in question is LIMO's g2T scan system, which, according to the company, is the world's fastest "Gaussian-to-Top Hat" converter with integrated scanning technology. “Our g2T scan system deserves its own entry in the Guinness Book of World Records," says Klaus Reinecke, Vice President Sales at LIMO Lissotschenko Mikrooptik GmbH. "What other comparable system on the market can handle laser structuring at a scan speed of 20 m/sec?” Introduced in 2013, this potentially record-breaking complete solution for users in the photovoltaic industry is specially designed for laser direct structuring with single-mode lasers (532 nm). Thanks to its 160 by 160 mm² scan field (spot size of 75 x 75 µm²), the system is primarily suitable for use in the structuring of solar cells. This incredibly compact system is ideal for the ultrafast, high-precision laser structuring of six-inch solar wafers. Due in no small part to its extremely fast operation, the performance of this complete module is not only more accurate, but also more cost-effective than that of other systems. Other highlights of the g2T scan system, which features a closed optical core with integrated galvo mirrors and a custom-made F-theta lens, include the quality of its written lines and the flexibility to freely program and quickly modify the cell design. “Our system will surely inspire manufacturers of solar energy equipment to come up with completely new ideas,” says Klaus Reinecke, Vice President Sales at LIMO. “Some examples of possible processes would be the doping of selective emitters on silicon solar cells and the targeted opening of layers. Partner with our application engineers to discover new applications for our record-breaking system.” There will be a few good opportunities to do so this fall, for example by meeting LIMO experts in person at the International Congress on Applications of Lasers & Electro-Optics (ICALEO) in San Diego, CA, USA (19 - 23 October 2014) or at the Glasstec trade show in Düsseldorf, Germany (booth 11A07 in Hall 11, 21 - 24 October 2014).  

Leggi tutto...

LIMO joins LIPA

Limo6LIMO steps up its engagement in the USA, aims to make laser technology a global standard. LIPA, the Laser Illuminated Project Association headquartered in San Jose, California, USA, is a joint body consisting of representatives of high-tech companies active in the visualization industry that seek to promote and develop imaging laser technologies worldwide. Many distinguished companies operate in this segment, including Sony, Philips, Mitsubishi, Panasonic, BenQ and Texas Instruments along with Jenoptik, Osram, Imax and Disney. Now Dr. Paul Harten, Managing Director of LIMO, is adding his company to the ranks of the renowned members of LIPA. “LIPA members believe that laser projectors hold many advantages over traditional projection techniques and that by joining their voices they can improve the business and regulatory environment for all”, as the organization’s primary objectives state. LIPA is therefore not only actively promoting laser projection – which is superior to the traditional technologies – worldwide but also functions as an internationally regarded forum that seeks to improve the business and regulatory environment of this groundbreaking technology. Its ultimate objective is to establish laser projection as a global standard. As an internationally leading specialist in laser beam shaping LIMO will as of now be using its membership to support the highly regarded joint body while stepping up its commitment in the US American market. Key Account Manager Roy Wetzel, LIMO’s representative in North America, is looking forward to the collaboration with the leading-name projector manufacturers who have come together in LIPA. “We are already the partner for many innovation-rich industries across the board from semiconductor manufacturing, flat panel displays and the automotive industry through to the imaging processing used in medical equipment”, says Dr. Harten. “Laser is the technology of the future – and LIMO is backing it at the international level.” 

Leggi tutto...

Russian tech workers to participate in training program at LIMO

LIMO5Around 1,500 miles (2,500 km) separate LIMO's Dortmund headquarters in Germany from the Russian State Technical University in Nizhny Novgorod. In May a delegation from LIMO Lissotschenko Mikrooptik GmbH paid a visit to "Eurotech," a University-affiliated education center which specializes in training future engineers. The name of the center stands for "Automobile Center of European Educational Technologies." The LIMO delegates were welcomed by Eurotech Director Alla Koshurina, who spoke with them about a new expansion building. The building, which is currently still in the early construction phase, will serve as a laser application center housing multiple laser systems for the cutting and welding technology application fields. This is where LIMO's expertise comes in: For over 20 years, the Dortmund-based company has developed and manufactured innovative microoptics and laser systems for applications in various industries, including materials processing for the automotive industry. During the visit to Nizhny Novgorod, LIMO and Eurotech explored the possibilities for a long-term partnership focused on the initial and advanced training of Russian engineers and technical specialists in industrial production, and they were also able to map out specific initial steps to begin the process. The first step will see three individuals from the training center in Nizhny Novgorod travel to Dortmund at the end of the summer. These three visitors will then complete an advanced training program in laser material processing, covering CNC laser machines and more, at the LIMO Application Center. "These training programs are supported by the Ministry of Education of the Russian Federation," explains Peter Bruns, Director of Application & Technical Service at LIMO. "On our visit to the Eurotech training center, we were shown test stands that are being used to prepare future engineers for work in the automotive engineering field. The new laser application center will be an important addition to this hands-on training segment." At LIMO, connections with Russia enjoy a long tradition. Company founder and CEO Dr. Vitalij Lissotschenko is himself a native of Russia. Many members of LIMO's very international staff also come from Russia and other Eastern European countries. Aside from German, the language spoken most frequently during work at LIMO is Russian – which can even be heard more often than English. Intercultural training sessions offered by LIMO have focused mainly on the cultural exchange between Germany and Russia. As a result, the three visitors from Nizhny Novgorod will find that excellent conditions are in place for well-functioning communication and friendly cooperation among colleagues for the duration of their training program.

Leggi tutto...

An Optimal Surface in a Matter of Milliseconds

Today, lasers are considered extremely versatile systems - systems believed to be capable of virtually anything by those outside the field. But now, at Dortmund-based LIMO, there is suddenly talk of using a laser source for surface heating which will surely astound even seasoned photonics experts. It involves a special application of the Activation Line 300, the most powerful L³ LIMO Line Laser source. “Imagine that a surface with a functional layer only a few micrometers thin is to be heated to over 1.000°C,” says Dipl.-Ing. Dirk Hauschild, Director of Thin-Film Activation at LIMO Lissotschenko Mikrooptik GmbH in Dortmund. “And think about doing this with a substrate that is already destroyed at 500°C”. But it doesn’t stop there: The layers that are to be optimized are often composed of small particles or molecules which lose their desired properties and structural size just a few seconds after the processing temperature has been reached. Here, there is a demand for fast and targeted heating and cooling. This challenge can be met with the use of an in-line high-temperature process that provides targeted surface heating in a matter of milliseconds. The Activation Line 300 was specifically designed to fill this need. With its high electro-optic energy efficiency of over 40%, the most powerful L³ LIMO Line Laser (a CW output of over 13kW with a homogeneous line focus 300 mm long) heats even the thinnest functional layers (thicknesses of over 0.1 µm to more than 100 µm) with an intensity of 40kW/cm² in a few milliseconds - delivering outstanding precision and consistency (beam quality M² < 3 in the processing direction) in the process. Because of the low thermal capacity, the layers also cool down again very quickly. “The laser energy thus serves to functionalize the layer and, as a result, add to its value”, says Dirk Hauschild. “Thanks to the targeted irradiation using the laser line profile, the user can uniformly temper large surface areas. The Activation Line 300 thus enables customized annealing, crystallization and sintering processes with fully closed surfaces”. “Precision tempering of coatings on glass, metal, ceramics, films and even on paper is also possible”, notes Hauschild. “For the production process, the user can also utilize extremely small energy and process windows that would otherwise not be feasible with the use of conventional technologies. I invite you to do the following: Come visit us in Dortmund and process your innovative materials and coating samples together with our team in our Applications Center to obtain the optimal design and customization of your Activation Line laser source”.  

Maggio-Giugno 2014

Leggi tutto...
Sottoscrivi questo feed RSS

Mercato

Comunicazione tecnica per l'industria