GIFA 2011: voxeljet presents inorganic binder system

voxeljet and Hüttenes-Albertus are the first to successfully produce inorganically bound moulds and cores using the 3D printing method, without the use of tools. With this innovation, 3D printing follows the growing trend towards environmentally-friendly moulding materials in foundries. The method also convinces in terms of quality. It will be presented for the first time at GIFA in Düsseldorf.

Inorganic mould

Modern and environmentally friendly production methods are in high demand everywhere. Particularly the automotive industry has set its focus on sustainability and ecology in production processes. Inorganic binders for the manufacture of sand cores have been used in engine production for some time already. In contrast to organic binders, inorganically bound cores provide a series of advantages, ranging from environmental compatibility to quality improvements for the finished cast parts.

Particularly the innovative Additive Manufacturing (AM) technology, which is used to produce sand moulds on 3D printing systems based on CAD data without the use of tools, has not been able to make use of inorganic binders to date. voxeljet, a manufacturer of high-performance 3D printing systems, and Hüttenes-Albertus, a leading manufacturer of products for the foundry industry, are now offering the perfect solution for environmentally friendly and high-quality 3D printing with a series-ready inorganic binder system.

The moulding material system developed by Hüttenes-Albertus in conjunction with voxeljet can be used on voxeljet 3D printers. In principle, the process for building the layers is the same as with organic binders. With the new system, moulding material containing inorganic binder - inorganic prepared sand - is applied to an area in micrometre-fine layers, and subsequently and selectively printed with a liquid. The printing solution activates the binder in the sand, which binds the surrounding moulding material particles.

This process is repeated layer by layer until the desired mould has been produced. After the printing process, the surrounding moulding material is removed from the moulds and cores. Non-printed particle material can be prepared and reintroduced to the process. Following the layer building process, printed components are dried in an oven for a few hours, and are then available for casting.

voxeljet CEO Dr. Ingo Ederer views this innovation as an important step towards more sustainable production: "Until now, inorganic binder systems have only been used in series production. Therefore we thought it was also very important to open the ecological and technological benefits to the innovative AM world. Now, users involved in small series and prototype production can also leverage the benefits offered by inorganic systems."

In some systems, inorganic binders are superior to products based on artificial resin. And contrary to organic products, inorganic binders do not burn during the casting process, thus avoiding the emissions that result from organic systems, which are harmful to the environment and health. The new technology also does not produce the typical odour that occurs during the casting process as a result of the burning of the organic material. The casting process does not involve odours or condensates. Therefore the method is deemed as environmentally friendly. At the same time, it also has a positive effect on the quality of the cast: For example, in the case of NE/L casting, the thermal stability of the inorganic binder during casting results in excellent stability of the sand moulds and hence ideal dimensional accuracy of components.

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