Rapid.Tech 2023 Additive Manufacturing: Machines and systems for 3D components made of metal, plastic and ceramics
At Rapid.Tech 2023 in Erfurt, AIM3D, supplier of 3D printers using the CEM (Composite Extrusion Modelling) process, will be putting the Exam 255 3D printer centre stage at the trade fair. The Exam 255 system combines high precision 3D components with high build speeds for additive manufacturing.
With the Exam 255 multi-material 3D printer AIM3D offers a solution that can be used across materials (metal, plastic, ceramic) and processes (hybrid components). Compared to powder bed processes or even other 3D printing processes that use materials with filaments, the systems of the CEM process achieve tensile strengths that come close to classic thermoplastic, mould-bound injection moulding. The price advantage with 3D printing is striking when commercially available granulates are used instead of filaments. When using granulates, price advantages of up to a factor of 10 result from the CEM process.
Competitiveness in 3D printing with granulates
The use of granulates in 3D printing with plastics proves to be competitive especially for parts with fibres. Generally, a distinction is made between fibre-reinforced (GF) and fibre-filled (when there are only short fibres). Two materials are particularly interesting due to their widespread use in the plastics processing industry: PPS GF40 (polyphenylene sulphide) and PA6 GF30 (polyamide).
They combine outstanding mechanical properties with media and temperature resistance. As a so-called pellet printer, the Exam 255 uses commercially available pellets, which are also used in injection moulding. This results in a very competitive pricing of 3D printing using the CEM process compared to conventional manufacturing strategies. The price advantage in material cost for a processed component ranges between 80 and 96 percent depending on the material group. Such components usually have a higher density with high tensile strengths. For the processor, there is also a high degree of flexibility, as the material does not have to be modified. Identical, certified material means the same or comparable properties, such as thermal conductivity, media resistance, damping, mechanical properties, shrinkage or density. In addition, long-fibre reinforcement with up to 3 mm fibre length is possible, with a filler content of up to 60 percent.
The material grind of PA6 GF30 demonstrates another characteristic of the Exam 255 system: it offers high sequence fidelity of the fibre orientation with the extrusion paths (pressure of the fill/infill +45°/-45°). The web control can be used during printing to optimise the strength of the component. The economic efficiency results not least from the favourable machine hour rates and the high energy efficiency of the 3D printing system. The sum of the characteristics of an Exam 255 offers enormous advantages in 3D printing, as polyamide applications are very widespread and a price-adequate 3D process is offered here for the first time.
High precision in 3D printing
The accuracy of a 3D printer is crucial for processors. The Exam 255 achieves accuracies of up to 25 µm, depending of course on the build speed. The level of precision on the component results from the design: two pellet extruders work in the build space of the Exam 255, which are supplied with material via separate feedstocks. The build envelope itself measures 255 x 255 x 255 mm3 and can be passively heated up to 60°C. The build rate (with a 0.4 mm nozzle) is quoted by AIM3D as up to 40 cm3/h, depending on the material selected.
Multi-material spectrum opens up a high degree of flexibility
The flexibility of the printable materials plays a central role in the investment decision. As a unique selling point, the Exam 255 covers a very broad spectrum of materials. In the metals group, the focus is on steels, titanium, non-ferrous metals and hard metals. In the case of plastics, identical types of plastic can be printed on a granulate basis, as is known from classic processes. Ceramic applications can also be added. Material is fed to the Exam 255 via paired material containers (feedstock) above the installation space of the Exam 255. This arrangement enables multi-component printing of polymers, but also combinations of metal, plastic or ceramics. The options of this system technology also enable process combinations with hybrid components, where one component is classically manufactured and a second component is printed. This results in many perfect solutions for almost any industrial application.
References in institutes and industry
In addition to numerous institutes that use the Exam255 for rapid prototyping and materials research, well-known industrial customers also use the Exam 255 multi-material 3D printer, including industrial users such as Brose, Schunk, Schaeffler and BASF. For these users, the focus is on small and medium-sized series using 3D printing. The acceptance by the processors results strategically from the use of series material. This shortens development times enormously and the components are visually and in terms of component properties close to series production. Alternative component designs with bionic properties and lightweight construction strategies can also be tested on the Exam 255. Another significant advantage is the one-shot technology: a component is built up successively without assembly effort, even with function integration. A conventional component can be constructively and functionally optimised by means of an additive manufacturing strategy through reengineering. The special charm of the CEM process is material-hybrid and process-hybrid 3D component geometries for maximum flexibility and design freedom. In terms of economic efficiency, flexibility, precision and build-up rates, the Exam 255 offers ideal conditions for opening up additive manufacturing as a supplement to conventional manufacturing strategies.