LASER: higher efficiency, lesser efforts

July 22, 2014 6:17 pm

Lesser in effortsAccuracy in applicationsSimple in handlingEfficient in operationReliable in outcome
 In today’s world, laser technology is growing in diverse industrial applications. Though the automotive sector has predominantly implemented the laser technology as a new alternative to traditional manufacturing processes, today laser technique is enjoying its presence in various applications, from automation to optics, and from telecommunication to security.
Laser cutting is a technology that uses a laser to cut the materials, and is typically used for industrial manufacturing applications. India is growing global automation hub primarily on account of labour and easy availability of technology.. Here we discuss about the latest innovations in laser cutting machine tools and overall laser use in machine industry.
Latest trends in laser cuttingLaser cutting machines allow metal fabricators to create high-quality parts that require very little, if any, finishing work. As the high-powered laser is cutting, excess material either melts, burns or vapourises away. A high pressure jet of gas also blows away any debris, resulting in a highly finished surface cut.
Two types of laser cutting machines mainly in use are CO2 and Nd:YAG. CO2 laser cutting machines were one of the first gas lasers and are the most common variety of laser cutting machine. They offer an excellent power input-output ratio, as efficient as 20 per cent. Nd:YAG lasers are solid state and use a crystal as a lasing medium. They cut steel and other alloys in the metal working industry.
As laser technology is continuously developing, it is interesting to see what are the latest technological advancements and innovations being offered by the current players in industry. Let’s have a look at the same.
“We have come up with latest CNC structure with power automation (German) controller,” says Jayesh Patel, Marketing Director, A Innovative International Ltd. “Also we are having solution of slab technology for CO2 source for which maintenance is also very less and is safe in operation. We provide latest fibre technology with different suitable structures which ultimately gives reliability and flexibilities to customers.”
“Quality of cutting and efficiency of operation are the two key aspects that are in much focus at our R&D centre. The operating cost and consumables for our fibre laser cutting machines are almost half that of the conventional CO2 technology. Our fibre laser cutting systems ensure lowest maintenance cost as well,” assures Maulik Patel, Executive Director, Sahajanand Laser Technology Limited (SLTL).
Maulik Patel also informs about what SLTL has done in this regard to offer its other features which include:• Butter cut: The glossy and smooth finish on steel of thickness varying from 5 to 12 mm; achieving the finish at this thickness level at a high speed is what considered as a key advancement in technology.• Striation free edges at thicker metals. The angular distortion caused in the conventional non-contact type cutting system has been corrected and the finish has been improved with various evolutions. The dynamic edge control mechanisms have been developed to control the pressure of assist gases, cutting speed and laser power in order to deliver perfect geometry and to achieve least angular distortion.• 1G to 5G acceleration has been able to achieve with modifications in design and redefining material technology, for point to point positioning it has been saving time and electricity to a large extent.
Laser cutting vs. mechanical cuttingLaser cutting machines are distinct from traditional mechanical cutters. Since the laser never makes physical contact with the metal, there is little to no wear on the equipment, and there is less opportunity for the material to become contaminated. Laser cutting machines also cut metal with higher precision than that of mechanical means.
According to Jayesh Patel, laser cutting offers benefits like no need of tooling, no mechanical stress on cutting edge, and making variety of cutting profiles possible in a single setup.  It is also possible to cut non-metals with the help of laser. Moreover, laser cutting gives higher material scrap value too and is suitable for wide range of applications.
Explaining how laser cutting is advantageous, Maulik Patel says, “Unlike the conventional cutting processes namely punching and turret press, lasers have two indigenous benefits i.e. non-contact type cutting and profile cutting. Profile cutting with fibre lasers has equal preference in lot manufacturing these days. Thanks to the very high speed of cutting, precision and best-in-class quality of finish achieved through fibre laser technology.”
In mechanical cutting, there is usually a wide heat affected zone that can cause material warping from time to time. However, as in case of laser cutting machines, the heat affected zone is kept small, possibility of warped material gets significantly reduced.
Although laser cutting offers numerous advantages, it also consumes a very high level of energy, making it more difficult for a conventional machine shop to incorporate into its metal fabrication system.
Reflecting surfaces: a concernWhile exceptional for cutting steel and other hard metals, laser cutting machines typically do not function well on highly reflective metals, like copper and aluminium. Since these metals easily reflect the laser’s light and also absorb its heat, highly-powered beams are required to cut them. Also when piercing, laser cutting machines create slightly tapered holes due to the hole entry being slightly larger in diameter than the exit.
“Catering to defence and aerospace industries, now the fibre lasers are capable of cutting reflective metals and even metals with special coatings,” says Maulik Patel. “This is possible in two ways. One is to increase the power of fibre laser cutting system and have slightly different optics design with laser’s wavelength to work on reflective metals. Else to adjust the focal lens in the cutting head in a way that it does not get hampered with the laser reflected from reflective materials. In some cases, the cutting head is tilted in a minute angle to avoid the back-bashing of laser.”
“Generally for reflective materials fibre laser is recommended. However, in case of CO2 laser, ATFR mirror could be installed (back reflection unit) to prevent damage of laser source due to reflection of laser beam,” suggests Jayesh Patel.
Since laser cutting melts the material in the beam’s path, metal can harden in the puncture, especially in heat treated material. While this may be beneficial for some applications, this issue can be detrimental to those requiring further work, like threading.
Application areas and future scopeNowadays laser cutting machines are finding their applications on large scale in various fields like sheet metal fabrication, architectural and hardware segments, enclosures, pharma machineries, agro equipments.
Fibre laser cutting system has its applications at wide range of industrial segments. Fibre laser cutting of course is one of the apt solutions for precision engineering. With the growing industries focusing on precision and accuracy, there is a booming market with wide open gate for fibre laser cutting systems. “It’s not only the economic performance of the system that stood best. It’s the quality of cut, repeatability and accuracy achieved through fibre laser system made its penetration into other applications as well,” adds Maulik Patel. “Other than sheet metal industry, structural fabrication and heavy engineering, tube, angle and bevel cutting applications also have felt the need of fibre lasers.”
Fibre laser with power options less than 1kW is now emerging as a replacement for turret punch. The low power fibre laser is now finding its place in the turret punching industry due to its capabilities in profile cutting, and investment.
ConclusionIn all, as laser technology will always keep exploring itself in many segments, we can say that it is clearly offering a bright future not only to machine tool industry but overall world of ever-increasing and ever-changing technology.
————-Laser cutting offers benefits like no need of tooling, no mechanical stress on cutting edge, and making variety of cutting profiles possible in a single setup.
Jayesh Patel, Marketing Director, A Innovative International Ltd.————-
————–The operating cost and consumables for our fibre laser cutting machines are almost half that of the conventional CO2 technology.
Maulik Patel, Executive Director, Sahajanand Laser Technology Ltd.(SLTL)