The origins of 3D printing/additive manufacturing
The origins of 3D printing/additive manufacturing
With some news stories you really have to check the date to make sure someone‘s not playing an April Fool’s joke. For example, the Italian pasta company Barilla has introduced a pasta printer that can create pasta according to customer specifications on site. Or: The American-Russian company Apis Cor uses a robot to print compact concrete houses for around 10,000 US dollars. Or: Mercedes-Benz rolls out metal 3D printed parts for its older truck series. Or: Adidas brings 3D printing to the masses with printed sneaker soles. Or: In medical technology, ceramic dental crowns, plastic hearing aids and metal artificial knee joints are being printed – and in the future even entire organs may be 3D printed using alginate, which contains living cells.
The first 3D printer was invented by the American physicist and engineer Charles Hull back in 1984. At that time, the process was not called 3D printing, but stereolithography – just as it is today. In fact, there are many different processes that come under the colloquial umbrella of 3D printing. Besides stereolithography, these include laser melting, laser sintering, polyjet modelling, digital light processing and fused deposition modelling. The choice of process depends on the raw material. The most commonly used materials are ceramics, synthetic resins, metals and – the domain of Dressler Group – plastics. One thing all these processes have in common is the term “additive manufacturing”, which denotes that the material is built up by gradually adding more of it, usually in layers. By contrast, subtractive manufacturing involves removing material, for example by milling, turning or drilling, until the desired result is achieved.
The manufacturing process
“You can’t say that one manufacturing process is superior to the other overall,” says Axel Dressler, “because each is better suited to certain applications, and sometimes the other is not applicable at all.” Where additive manufacturing is an option, the latest developments (examples above) can certainly be described as revolutionary. Where both processes are applicable, the various additive manufacturing alternatives often bring considerable advantages. Efficiency is a case in point. Firstly in terms of material input. After all, you are not removing superfluous material, but adding precisely what you need. This reduces costs as well as processing and cleaning steps. Secondly, in many cases this significantly shortens the time involved, particularly by eliminating the need for conventional mould and tool making. The bottom line is that small batches or even individual items can be produced profitably, while also minimising storage requirements – the key words here are rapid prototyping and print on demand. Due to the layered construction, it is also possible to create extremely complex filigree shapes or internal cavities, which subtractive methods can only produce with great difficulty, if at all. Fully functional prototypes and series parts can also be manufactured with minimal work. Choosing the optimal process for a particular application in the required quantity is always a matter to be considered case by case.
Dressler Group as a partner for 3D printing/additive manufacturing
Dressler Group (DG) comes into play when considering the plastics that will be fed into the (printing) machines. “Experience and regular dialogue with our customers have shown that we function as a kind of ‘missing link’ between the raw material, on the one hand, and the printing process on the other,” says Axel Dressler. “So rather than the raw material itself, the key to success is a plastic that we have processed and refined to precise specifications.” In other words, only the grinding and finishing processes developed by Dressler Group make the raw materials suitable for printing – and now enable applications that used to be technically impossible. The crucial parameters include grain shape, grain size, flow properties, the option of additive-free materials and the purity of the powder. Without these considerations, certain details and structures could not be produced, the strength and durability would be insufficient, or the machines would be prone to failure because of materials sticking together. Dressler’s processes also open up new possibilities in terms of efficiency and environmental protection: due to the specific properties of our plastic powders, the residues are completely recyclable, material yield is significantly higher and overall energy consumption is lower. Contaminated material and waste residues are avoided altogether.
Experience and regular dialogue with our customers have shown that we function as a kind of ‘missing link’ between the raw material, on the one hand, and the printing process on the other. So rather than the raw material itself, the key to success is a plastic that we have processed and refined to precise specifications.
All processes and plants have been developed by and within the Dressler Group itself since the company was founded in 1978. This brings two advantages: First, absolute discretion. And second, the highest possible degree of customisation. The latter also ensures audit-proof documentation of all procedures. Naturally, Dressler Group has all the standard industry certifications – besides further credentials. For customers, this means products are perfectly reproducible at any time, in any quantity. “One of the reasons we are so successful in getting the most out of plastic powders is that our chemists, process engineers and plant engineers work extremely closely with our customers,” says Jan Dressler. “After all, we manufacture for their needs, not ours.” The experts also have extensive discussions with leading manufacturers of plastic powders and 3D printers. This hand-in-hand approach has always made the Dressler Group a problem solver and “enabler” for its customers.
At Dressler Group’s own two research facilities, the Innovation Lab and Technical Centre, small and very small quantities starting at just a few grams can be produced and tested. In addition, DG cooperates with universities to bring about an optimal integration of research, teaching and practice. This is all part of ensuring the highest efficiency and quality from the very start of production, because the strategy of taking small steps eliminates the risk of expensive development and investment errors. After all, a successful revolution needs the basics to function perfectly.