Layer by layer to success
Across the foundry industry, additive manufacturing enables foundries to produce prototypes and very limited series without high tooling and storage costs. Additive manufacturing also gives designers unprecedented freedom in the design of moulds and cores.
A technology of the future
3D core printing is a pioneering approach that HA is keen to explore in dialogue with its customers. We work together with universities, institutes and, of course, foundries and machine manufacturers to develop solutions specifically for the foundry industry. For example, HA has developed coatings with special properties that are perfectly matched to additive-manufactured moulds and cores. A specially configured 3D printer in the CoC also enables us to work more closely with our customers in this field.
The strengths of 3D printing
Even though we in the foundry industry usually talk about additive manufacturing – what results from it are perfect three-dimensional workpieces from the printer. In the binder-jet process, powder particles (sand or ceramic) and a binder are bonded together in such a way that almost unlimited shapes and geometries can be created.
With the right binders, additive manufacturing allows foundries to produce complex components that would otherwise be impossible or require a great deal of effort.
Additive manufacturing
- Makes it possible to produce complex cores and moulds
- Only requires CAD data
- Guarantees maximum flexibility
- Makes it possible to combine printed and conventional moulds
Efficient innovation processes
- Prototypes, single parts and small series can be produced cost-effectively – with no tooling costs
- New ideas and minor modifications can be implemented and tested immediately
Sustainable production
- Emission-free casting with inorganic binder systems developed specifically for the 3D printing process
- Almost no waste requiring recycling or landfill
- Opens up a range of technological possibilities for lightweight construction
How does Additive Manufacturing work in practice?
A moulding material (e.g. silica or ceramic sand) containing a binding agent is deposited in micrometre-fine layers onto a build platform. A printer head then selectively doses the layer with a powder or liquid activator. The printing solution discharged via the print head triggers the curing process that causes the moulding material particles to fuse together.
This process is continued layer by layer until the desired shape is produced.
After printing, the moulds and cores are freed from the surrounding unbound moulding material.
Depending on the system, unprinted moulding material can be returned to the process in whole or in part after further processing. Depending on the binder system and strength requirements, the cores and moulds are placed in an oven for a few hours after the layering process to dry them out and get them ready for casting. To improve their casting properties, the cores and moulds can be coated with one of HA’s specially developed coatings.
Products for binder-jetting
Hüttenes-Albertus has been pioneering additive manufacturing within the foundry industry since the dawn of the “3D printing age”. We offer a range of binder systems precisely tailored to all major printing systems.
Special emphasis is placed on the development of inorganic binder systems. Environmentally-friendly 3D printing is thus no more and no less than the next logical step towards an environmentally compatible end-to-end production process.
At the same time, we also feel obligated to further optimise our existing, tried-and-tested processes to more carefully steward natural resources and protect the environment.
3D printing with inorganic binder systems:
With our inorganic binder systems for series production, 3D printing aligns with the accelerating trend towards environmentally friendly moulding materials in the foundry.
Unlike organic systems, inorganic binders do not burn during the casting process and therefore do not produce smoke, odour or other environmentally harmful emissions. In order to speed up the reaction process, the build chamber is usually heated using infrared panels or bulbs.
Once the printing process has been concluded, the cores and moulds are then additionally cured in a microwave oven until their final strength is reached.
Resource Saving Printing with Furan Resin
Our furan binder systems allow for the use of both 3D printers with separate mixing systems, usually referred to as the dry-mixing process, and printers with integrated mixing systems.
We have developed qualified activators for both systems and matched them to our binder systems. Owing to the stable storage properties of the activator and sand mixture, the mixing process can be decoupled from the sensitive printing process. The printed cores and moulds cure by themselves.
At least 30% of the activated unprinted sand can be reused and there is no need for post-curing in an oven.
3D printing with phenolic resin
As an alternative to 3D printing with furan resins, we also have a range of phenolic resins specially developed for the additive manufacturing 3D printing process. They feature excellent mechanical strength, extreme dimensional stability, exceptional contour sharpness and high thermal resilience.
Our phenolic binder systems make it possible to print complicated geometries and undercuts that would otherwise be very difficult or even impossible to produce.
The sand is not activated prior to printing as described above but is added as raw sand. Infrared lamps are integrated into the printing process to speed up the curing process. All of the unprinted sand can be collected and reused. This leads to excellent de-sanding properties in the finishing process.
Technical Article
Coatings for 3D printing
Foundries that use 3D printing for their moulds and cores can rely on products specifically developed for the process. The use of coatings specially developed for 3D printing can prevent the formation of rough casting surfaces and sand adhesion. ► Find out more
The strengths of coatings for 3D printing:
- For application in iron, steel and aluminium casting
- Avoidance of casting defects
- Smooth surfaces
- Application properties tailored to different printing processes
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