A prototype overnight
Today, Freudenberg’s inventors don’t generally contract out the production of models of their inventions in a lengthy process: instead, they make them themselves in just a few hours, right in the Office – thanks to 3D printing.
Added expense and complication – that used to be the case when the inventors at Freudenberg needed a prototype that was truly close to the final product. That was because the most commonly used stereo-lithography and laser-sintering “rapid prototyping” processes were slower than they sound. “Machines like that are also very large and cost upward of 200,000 Euros, which simply wouldn’t be a worthwhile investment for us”, explained Peter Capuani of Freudenberg Filtration Technologies. He manages the assembly center for filters, where the developers themselves make the prototypes and models of new inventions. In the past, his team members usually only had the option of going to an external service provider if they needed exact, functional prototypes. “For each model, you first have to find the right manufacturing process and then send several inquiries with the specifications to various Providers”, said Capuani. “It can take two weeks for the order to be placed.” The costs for a single prototype can then easily be more than a thousand Euros.
For the last seven years, Capuani and his team have had another, much less expensive and faster tool at their disposal to validate their colleagues’ constructions: their own 3D printer. Suddenly, you don’t need two weeks to see if the design of a new product needs improvement or not. Two hours is sufficient and, in the best case, each prototype costs just 50 Euros. “So if a design isn’t perfect, it’s not such a big deal”, Capuani commented.
“The advantage of 3D printing is that you get feedback really quickly and can go right back to working on the product.” A rounded corner on a filter casing might be changed and the construction data adjusted, and the printer will make you a new model overnight. It’s also useful for making tools: “We make much of our own equipment with it: for instance, combs that we need as mountings when gluing filters,” Capuani continued.
A TV is too big to print with this 3D-Printer, but it can
print models that are the size of a telephone.
Visions you can touch
Sometimes, printed inventions do make their way to the outside, quite intentionally: “It is always terrific to be able to take an idea to a customer and put it right into their hands as a model.”
But despite the many benefits of the 3D printer, a lot of orders still go out to specialist prototype makers later on in the process. This is because their vacuum casting methods make it possible, for example, to produce ten, twenty or fifty samples at once – in excellent quality. “These are fully functional and look almost exactly like the subsequent final injection-molded product,” Capuani explained. “With a 3D printer on the other hand, you can usually still see the layers that the printed model is made of.”
Size was important
The most important criterion that needed to be fulfilled when the 3D printer was purchased for his department for around 30,000 Euros was that it had to be able to make the biggest possible items: “We can print models that are the size of a telephone, but a TV is too big”, said Capuani. At present, the maximum dimensions possible are 250 x 250 x 280 mm. Bigger models can be assembled by sticking printed components together with super adhesives, but he would still like to have devices at his disposal sometime in the future that can print bigger products.
3D printers can produce any shape imaginable.
Any shape can be made
Colleagues at Vileda now also develop new household products with two identical 3D printers. They come from the market leader for 3D printers, Stratasys, and melt an ABS filament. In a similar process to an inkjet printer, nozzles “print” layers of the liquefied acrylonitrile butadiene styrene on top of one another. The printer knows where to place the material because the three-dimensional data from the CAD program is converted into a two-dimensional system of coordinates. “We call that ‘slicing’. The model is cut into slices, so to speak”, explained Uwe Dingert, head of the Development department at Vileda. As soon as a layer returns to its solid state, the part is lowered and a new layer is sprayed onto it. This is repeated until the item is finished.
3D printers can produce any shape imaginable, but sometimes need accessories to help: “If you plan an overhang, you need supports so that gravity doesn’t cause the plastic to deform”, said Dingert. “The material you use to hold up the overhang later dissolves in water or can be easily snapped off.”
Many steps before a product is ready for the market
Dingert is also the International Director of Innovation at Freudenberg, and was one of the main advocates of acquiring the 3D printers. Both are in operation nearly every day in his offices. Whether a new bucket or an ingenious mop: before the tools for the injection molding process are made at high cost and the new products can go into serial production, every invention passes through numerous design and approval loops using the prototypes. “Some ideas you simply have to be able to touch in order to judge them”, explained Dingert. “Take a bucket, for example: you have to try it out. Does the wringer fit properly? Is it easy to carry and empty? Does it look good?”
The 3D printer is the tool of choice for fast results: “In traditional model-making, a specialist had to mill a geometry in metal by Hand”, Dingert explained. “While the printer can produce a figure the size of a shoebox in 24 hours without human intervention, that same piece would take an experienced model-maker about a week.” The experiences with the printers have been so good that Dingert is already looking for a new one that works on the polyjet principle. “Colleagues in Chicago have already bought a polyjet machine, and it can process different materials of various consistencies – even rubbery ones – simultaneously!” The avid tinkerer doesn’t even attempt to hide his enthusiasm at the thought. In his opinion, if used properly, this kind of technological option will only improve the quality of the products even further.