With the advent of Industry 4.0, digital manufacturing promises speed, directness, and flexibility — so it needs a tool that meets those demands. Fortunately, the right technology has been evolving and is poised to step into that role. Laser systems have long played an integral part in the evolution of medical device manufacturing, and many production planners already have experience with this highly mature industrial tool that is the perfect choice to meet the new requirements they are facing.
When asked where the future of manufacturing lies, most engineers mention concepts such as data analysis, programmed algorithms, smart ultra-flexible part flow, and connected machines. “One question is often left unanswered, however: ‘What tools will we be using to machine the workpiece in all these highly connected, flexible operations?'” says Andreas Gebhardt, a professor at the Aachen University of Applied Sciences and a pioneer in additive manufacturing and Industry 4.0.
The problem is that data is intangible, yet at some point it must be turned into products we can touch. “Digitalization is crying out for a tool that offers the same fast, flexible, and physically unconstrained benefits that it does. And that's a pretty good description of a laser.” After all, when it comes to laser machining, the only thing standing between data and form is a focused beam of light. Yet that light can do so much, from ablation and material deposition to drilling, cutting, joining, producing metallurgical changes, and inducing intrinsic tension in glass, as well as roughening, smoothing, and cleaning surfaces. Lasers are on for just about anything.
“And the benefits don't stop there,” says Gebhardt. “One of the biggest advantages of lasers is that they can process whatever material you like, from metals and glass to plastics and even skin.”
Four Actions in a Revolution
Medical device manufacturers have been using laser systems long before anyone was talking about connected manufacturing or Industry 4.0. “Laser technology was digital right from the word go because it can only be controlled numerically — you could almost say that data-based manufacturing is in its DNA,” says Gebhardt. “When laser experts hear about Industry 4.0, they simply take it in stride.” For everyone else, it feels like a revolution. And there are four key actions to this revolution that are playing out simultaneously:
- Manufacturing chains with lasers are on their way in; manufacturing chains with mechanical tools are on their way out.
- The workpieces themselves are turning into data carriers with the power to communicate.
- Parts can change shape with each different set of data.
- Parts are being made completely from data sets.
Action 1: Fighting for Greater Variety
Marketing departments always want to offer potential customers products that match their needs. Meanwhile production planners field one request after another for new varieties and small batch sizes. And that's especially true for manufacturers that depend heavily on mechanical processes such as milling, punching, sawing, and drilling. The costs of toolmaking go through the roof — and tool setup times stretch out to absurd lengths.
Increasingly, setup takes longer than the production process itself. This was the situation faced by Zwilling, a German knife manufacturer based in Solingen. After the drop forging process, the company would use a punching machine to remove the final blade geometry from the blank. Ulrich Nieweg, who heads up Zwilling's prefabrication department, says, “We were building a new punching tool every time we had a new product or a change in geometry. It was tremendously costly and time-consuming, and so was the constant tool repositioning.” To tackle this problem, they opted for a laser cell that is loaded and unloaded by two robots — a flexible and programmable solution. Now they simply send across a new data set. So, is the laser cheaper than the punching machine? That question misses the point entirely. Companies that choose to rethink their production processes and manufacturing chain understand that laser light offers a level of freedom that mechanical processes simply can't match.
This shift in thinking is now taking hold in all sorts of places. A Swiss mechanical engineering company uses the same set of laser optics and the same beam source to process coils of different sizes made from different materials, first making a precise cut and then welding them together. The automatic switch from cutting to joining is seamless. Meanwhile the shears and TIG welders have quietly disappeared — and nobody wants them back.
Action 2: It Can Talk
Things get even more connected when the parts themselves can communicate with the tool to say how they should be handled. Argo-Hytos, a German manufacturer of hydraulic and filter systems, is one place where the laser head asks each part, “What can I do for you today?” Joachim Fischer, who heads up manufacturing process technology at the company, explains how this works: “We produce lots of short-run batches based on a strategy of zero setup time.” One example is the laser transmission welding of plastic filters and tanks. The scanner optics in the laser cell are mounted on a robot head and fed by a diode laser. The optics move freely around the work-piece, forming the welds in the correct places. Every part that enters the laser cell has a bar code.
The code tells the machine what to do, so it can fetch the relevant parameters from the database and get to work. Argo-Hytos works with many kinds of plastic. “In many cases, even the supplier of the semifinished product doesn't have accurate information on its laser transparency.” That's where the pyrometer integrated in the optics comes in handy, monitoring the temperature in the melt and providing data to the laser robot in real time. The robot and beam source adjust the power output as they work, producing optimum welding results. “It boosts the efficiency of our manufacturing process and produces even the smallest batches at a level of quality you would normally associate with largescale production,” says Fischer.
Laser systems can also teach work-pieces to communicate in the first place. Machine tool manufacturer Chiron, based in southern Germany, has incorporated a marking laser into its laser cells that provides each finished part with a data matrix code. “Normally the production data includes information such as the time the part was manufactured, the processing station, the supplier number, and the order number. But, you can also add other codes to the marking,” explains Thomas Marquardt, head of automation at Chiron. For example, these codes could tell a transport system where the part needs to go and explain to a control system at the next processing station what program it needs to load. This transforms the work-piece into a carrier of its own blueprint — and it marks the beginnings of a genuine smart factory.
Action 3: Data Is Changing
Modern data-driven production, which offers a way to construct geometries, is entering the next phase. “Additive manufacturing is turning the process for manufacturing many components on its head,” says Gebhardt. That's exactly what Elfim, a high-tech contract manufacturer in southern Italy, is doing. Starting with an unspectacular milled base, the company uses laser metal deposition to construct complex blades for various impellers. “We used to start with a metal block and then mill away more than 70 percent of the material to end up with the right impeller geometry,” says Michele D'Alonso, the company's co-founder. “Now we just add the necessary material instead of cutting away the unnecessary.” Not only is this process faster and more resource friendly, but the final impellers are also better. “With laser material deposition, we can construct other, more exact blade geometries.
Although Elfim is manufacturing its impeller blades using a different method, the blades essentially look the same as before. “Yet designers all over the world are discovering that additive manufacturing offers the ability to completely rethink parts,” Gebhardt argues.