Customers demand part marking for reasons that include component recognition, traceability for warranty issues, ISO compliance and counterfeiting. However, because the actual marking process is typically viewed as a non value-added operation, manufacturers are demanding the most efficient and cost-effective technology available. Of course, workpiece material and quality requirements also have a significant impact on the purchase decision, but with a plethora of new developments and equipment coming to market on a seemingly constant basis, manufacturers are provided with, in football parlance...a real selection headache.
Laser has become the most talked about method of producing marks on components and there are several reasons why. Laser marking offers permanence, high speed, short set-up and no wear of parts used by the more traditional contact-based marking equipment.
These reasons were certainly enough to persuade Optimum Precision Engineering of Ely, Cambridgeshire, to invest in a CombiLine Cube laser marking system from Rofin (01327 701100). Optimum Precision is a subcontract supplier, serving industries such as aerospace, medical, instrumentation and automotive. The company typically produces machined components in ferrous and non-ferrous metals, as well as more exotic materials, such as invar and titanium. The Rofin CombiLine Cube laser marker was acquired to perform radial marking on a specific component and it has not only simplified the process, but reduced the turnaround time on the parts by half.
The CombiLine Cube is available in a number of configurations and the Optimum Precision system is fitted with a Rofin PowerLine F20 fibre laser source and a servo rotary axis. This configuration allows the system to mark flat components and cylindrical parts such as micrometer barrels.
Image: The CombiLine Cube is available in a number of configurations
According to Rofin, the system can be used to generate alpha-numeric content, vector or rastered graphics, grey scale, barcodes or data matrix codes. When used on dark anodised surfaces, the laser ablates a few microns from the top layer, exposing the material underneath and producing a clear light coloured mark. On steel or stainless steel surfaces, the annealing effect from the laser beam produces a darker contrasting mark.
Another supplier of laser marking technology, Electrox (01462 472400), says it has completed the sale of an advanced system to a large domestic appliance manufacturer for marking operating control panels on its dishwasher machines.
Electrox provided two EF-technology Raptor II-based laser marking workstation systems to Arcelik in Turkey for its Beko and Arcelik white goods brands. Each integrated marking system comprises two lasers, a programmable Z-axis and fixing system for holding the control panels during the laser marking operation.
At the heart of the marking systems at Arcelik is the Raptor laser – the first laser marking system to be powered by EF technology. This technology provides very short energy pulses – 25 ns, compared with anything from 70 to 200 ns in other systems – which enables high peak powers (up to 10 kW), combined with low pulse energies. This permits high contrast, low damage marking on metals and plastics. The highly controllable beam virtually eliminates surface damage around the mark, enabling EF technology to be used for marking components where surface finish and retention of material integrity are paramount.
EF technology delivers very small spots, typically 70 micron from a 254 mm lens. Smaller spots are possible (down to 25 micron) with high speed, self-tuning digital signal process (DSP) galvanometers. This creates high energy intensities to give a substantially improved performance, compared with more traditional systems, says Electrox.
Another laser marking specialist promoting a new innovation is Gravograph (01926 884433), part of the GravoTech Group. Made up of a platform that can house an object with a maximum volume of 610 by 305 by 145 mm, coupled with a YAG 12 W source, the new LS100EX YAG presents the particular advantage of being able to mark hard or reflecting materials (such as black or stainless steel) as well as it can conventional engineering materials.
Image: The LS100EX YAG can mark hard or reflecting materials
The unit is controlled using LaserStyle software, an intuitive interface specifically developed by specialists for laser marking. It features automatic composition possibilities, such as the integration of lists of names and incrementation of numbers, gearing it up for high productivity applications. This claim is supported further by a maximum marking speed of 2.5 m/s and a front- loading design to cut operating times between batches of parts.
Of course, laser marking is only part of the story. An alternative technology is offered by another company in the GravoTech Group, Technifor (01926 884422), which has recently unveiled its XF500Zm marking solution. The XF500Zm is a column-mounted micro-percussion system, incorporating a motorised axis, an M1Cz stylus and a touch sensor in the marking zone.
Image: It isn't all about laser: mechanical marking still has a place
Technifor says the new unit stands out through its simplicity of use. Just position it on a workbench, plug it in and start marking. The keyboard is supplied and the software integrated: the user has all the traceability text, counter, date, serial number, Data Matrix codes and logos readily available. Characters from 0.5 to 99 mm in size can be marked at a rate up to five per second on a marking field up to 100 by 120 mm, and for parts up to 300 mm high. All types of materials can be marked, whether metals (62 HRc maximum), alloys or plastics...and on all shapes and surfaces, whether flat, convex, machined, as-cast or painted.
Despite the emergence of laser marking, demand remains high for dot/peen marking equipment, as Universal Marking Systems (0208 898 4884) can confirm. In fact, the company says that its new range of SIC dot marking equipment (showcased at the MACH 2010 exhibition in June last year) was a huge success, receiving a lot of interest for the new benchtop models, as well as the portable and integrated systems. UMS received its first order at the show itself and subsequent orders the week following the exhibition, including several multiple system orders.
There is little doubt that part marking is playing an increasingly important role in manufacturing. Growing numbers of companies are automating their marking processes, whether through Data Matrix codes or human readable text. If properly integrated into the production process, marking can provide a platform for improved quality control and traceability that reduces costs and improves yield.
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Productivity in print Compact and user-friendly, the new electromechanical, servo-driven TPM 101 pad printing machine reaches a printing capacity of up to 4,200 cycles per hour and is available in the UK from Kaye Dee Marking Solutions (0114 256 0222).
Image: Electro-mechanical marking at 4,200 cycles/hour
There are not only optical reasons that make control via the new, coloured touch screen one of the highlights of the TPM 101: a clear, easy menu structure, supported by visual depiction, provides high levels of user-friendliness, says Kaye Dee. In this way, the user can choose between the available parameters of functions and make any requested adjustments. A visual depiction of position makes the process even simpler.
