3D printing can be used to manufacture spare parts, prototypes and even human body parts. The weakness of the technology has been expensive raw materials and the large time requirements. However, with the help of an industrial robot, it’s possible to print large objects economically and faster – kayaks for example. In a smart industry, small series and custom products can be manufactured efficiently.
A 3D printed and customised kayak in plastic or wood fibre composite. Customers of Melker Kayaks will soon be able to purchase one of these. The company has just printed two prototypes and are now outlining the business concept and how the production will be organised.
The kayaks are just one example of the possibilities that open up if you employ an industrial robot to manage the printing. As early as 2013 researchers at RISE contemplated how they could 3D print large objects. Ideally, both faster and cheaper than what the very limited printers at the time could achieve.
Traditional technology and robotics in combination
The solution was to use a traditional extruder for plastic that was mounted on an industrial robot arm. A unique collaboration with ABB Robotics, which manufactures industrial robots, allowed the idea to take shape.
“Well, one outcome was we were able to find a way to quickly transform data from CAD drawings to robot code, which is normally a slow process that needs to be carried out manually,” says Emil Johansson, researcher at RISE.
Test bed since 2017
In the summer of 2017 the informal trials became an official project (DiLAM). To test the technology in more detail, RISE, ABB, Chalmers, The Wood Region and another 13 organisations built a test bed, financed by the strategic innovation programme Produktion2030.
“And now we are in the process of printing furniture, different tools for, among others, vacuum designs used by industries as well as other parts,” says Emil Johansson.
In addition to the ability to print large objects, the technology also has several other important advantages. Speed has been mentioned as well as the cost. The new technology means that bulk plastics in granulated form can be used instead of the much more expensive plastic wire spools used in 3D printers.
“It is also possible, for example, to use fibre glass composites and carbon fibre composites. Melker Kayaks would like to use recycled plastics or bio-composites with natural fibres from wood, flax or hemp in their kayaks,” says Emil Johansson.
Customisation of individual products
Another significant advantage is that the objects can be customised to meet individual customer's requirements.
“Yes, small series can be manufactured quite efficiently and without being really expensive. I believe that the automotive industry will benefit from this. They can choose to manufacture 10-100 customised components instead of perhaps today’s 100,000. End consumers will be able to buy customised products at a reasonable price,” adds Emil Johansson.
Multiple manufacturing stages in the same process
Through tool changes on the industrial robot, the technology also provides the opportunity to add several process stages in the same manufacturing cell. Including: milling, surface treatment, bonding and plasma treatment.
“It gives companies a new freedom. They can also 3D scan the product in the cell to verify that it was as intended. And the fact that the robot arm can print from any angle means you can actually say that this is 3D printing for real,” says Emil Johansson.
While conventional 3D printers have to add thousands of thin layers to each other, the robot can print one side of a component first, then the other and then put them together. The robot can also print on a diagonal or curved surface.
Monitoring the process with a stereo camera (with two lenses) lets you follow production in real time and assess the appearance of the component in 3D.
Unique in Sweden
“With this production, we are unique in Sweden and among the leaders in Europe. I think this type of hybrid between additive and traditional manufacturing is the future because it gives so much freedom and flexibility,” concludes Emil Johansson.
He mentions prototypes of cars, trucks and furniture as examples of applications. As well as the manufacture of house elements and tools to manufacture composite parts for aircraft, tools that today cost several million to produce and are only used to produce a few details.
Extruder
In simple terms an extruder can be described as a tube with a drive screw inside. The tube is fed with plastic pellets that are propelled by the screw and simultaneously heated to a malleable plastic material. When the material is pushed through a nozzle (extruded), it is formed and takes on a consistent profile.