7 minute read
technologies
20 technologies
Reinventing coil-fed laser cutting
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Francisco Pérez, Director of the OEM Channel
Although it may seem relatively new, coil-fed cutting 2D parts is a reasonably old practice and isn’t, for that matter, a process linked to laser. In fact, the first coil-fed machines, instead of precut standard formats, were plasma machines and, more specifically, machines aimed at the heating, ventilation, and air conditioning sector (HVAC) given that they mainly used thin layers, 0.6 – 1.2mm, generally supplied in coils. However, with the rise of fiber laser, its cost savings, its “ease” in terms of manufacturing and, subsequently, its drop in price and popularization, this market niche has paved the way providing quite a few advantages over the conventional laser that uses pre-cut formats and has a fixed work table. Here, we will focus on cutting with laser technology, although everything could all be applied to any 2D cutting technology (primarily plasma). We must remember that these machines are aimed at a specific market niche, that of thin sheet metal and with high production levels. Continuous format cutting (coil), improves on some problems encountered with the conventional laser, including: Optimization Of Time With conventional machines, using standard sheet metal formats (e.g., 3000mm x 1500mm) and thin layers, the existing laser capacities enable high-speed cutting (above 8000mm/min). This means that the time for changing the sheet metal
(table change) in regard to the cutting time of a full nesting (a piece of sheet metal) is sometimes over 30%. In other words, a third of the total cycle period is used for changing the sheet metal. Coil-fed machines don’t require as much material handling time given that they feed the cutting area continually. Optimization Of Material: Since it’s an “unlimited” format, the scrap metal left over from pre-cut formats is reused in the next work area. Depending on the types and mixtures of parts, you can save as much as 10% of the material. Fixed-bed machines limit the maximum length of the parts to the size of the beds, in a coil-fed machine, this limitation is eliminated allowing for parts of “any length” to be cut. Optimization Of Costs: Coil-fed laser cutting reduces the price of the material compared to purchasing it in formats (blanks). If we add to this the optimization of time, we find ourselves with a system that is well-suited for large volumes of repetitive pieces. But, just as with any new process, there are specific questions that need to be answered: -Evacuation of parts: If the sheet metal (coil) is moved, along with the parts that have already been cut, this can cause the material to collide with the machine’s surroundings. -Evacuation of scrap generated: During the cutting process, mainly when cutting holes, pieces of scrap are generated that may, once again, cause the material to collide with the machine’s surroundings. -Coil changing time: Despite the time improvements achieved by this process, if you had to change the material and/or thickness of the parts regularly, changing the coil may become a bottleneck. Each manufacturer has developed their own “solutions” to these first two issues: hatches for evacuations, micro-fasteners, skeleton destruction, etc., and it will be interesting to see which methods are most popular in the market. Continuing with the type of machine developed for the continuous cutting of material (coil), there are two groups:
-Machines that cut with the material stationary: These machines unwind a section of coil and supply a work area. At this work area, the machine works in the same way as a normal fixed or closedbed machine, moving the bridge and the head in XY. When all the parts have been cut in the work area (some parts may have been partially cut because they are longer than the work area or they are between two areas), the machine unwinds the coil again and moves/repositions the sheet metal. -Machines that cut with the material moving “on the fly”: These are obviously the most productive machines, but they are also the most complex/ expensive. Typically, given the fixed forward speed of the coil, at the work area, the bridge moves with the cutting head in XY, making high cutting rates possible. To achieve higher cutting rates, these machines have been equipped with two or three cutting heads allowing each head to cut a different part of the same piece simultaneously and achieving very high cutting rates. These machines were destined to compete with traditional press cutting “blanking” lines. In fact, they are often called “laser blanking” and they have been mainly seen in the automobile, OEM, and TIER1 markets. It should be emphasized that, given
the versatility of laser, this solution can be applied to any sector that requires a high cutting rate of parts. -There is also a small group of machines where the cutting head is fixed to a shaft and only moves in a cross-cutting direction when the sheet metal moves forward, and the sheet metal/coil moves forwards and backward. These machines are, obviously, more cost-effective, but have failed to have much of an impact on the market. Lantek offers programming to help get the most out of coil-cutting machine’s capabilities. Once again, software plays an essential role given that it not only controls but also provides the process with sufficient intelligence so that it can connect the different agents that intervene on the line.
24 innovation
Machine connectivity - Machine connect
José Antonio Lorenzo, Software Engineer
One of the main enablers of Industry 4.0 is the ability to connect to the machines in the plant and extract information about their status, their parameters, the work they are doing, and so on. Machine connectivity is vital to realizing the Industry 4.0 vision because it is the first link in the data processing cycle. If we have data, we can process it to obtain information which can enable us to better understand what is happening in the plant. This leads us to take actions aimed at improving productivity, which may eventually require extracting new data and/or metrics from our machines, thus closing the cycle. From a technical point of view, this first link is the most difficult. Once the data has been collected, completing the rest of the cycle is reduced to the issue of having the right software and expertise. However, the first step is usually the most complicated. Why? The machine tool ecosystem is extremely complex, with hundreds of manufacturers, highly specialized machines, and a multitude of features. Manufacturers are focused on making their machines faster and more accurate and have traditionally regarded connectivity as having lower importance. Fortunately, this is changing. An increasing number of machines incorporate some type of standard connectivity, such as the well-known OPC-UA. Despite all the difficulties associated with the pandemic, this year will see the release of the
UMATI standard which will be a major breakthrough in terms of machine connectivity. UMATI provides a standard vocabulary for communication with machine tools through OPC-UA and will undoubtedly be one of the standards that future machines will incorporate as an option. Meanwhile, the need for connectivity is a reality right now, and the installed base of machines does not yet incorporate such advanced connectivity mechanisms. It is therefore necessary to connect all these machines to continue taking advantage of the investments that were made in them without missing the Industry 4.0 train and the increase in productivity that it promises. Without losing sight of the evolution of the UMATI standard, Lantek is already working on offering its customers connectivity solutions that are perfectly integrated with the software it already produces. Lantek is a facilitator of the implementation of Industry 4.0 in the sheet metal cutting sector, and as such we provide the tools to make it much easier for our customers to achieve that first link we talked about at the beginning: machine connectivity.
