Digitalization in the foundry: 3D printing of sand molds and simulation

Casting is thousands of years old craft, but it does not mean the trade stands still. One of the technologies that really disrupts the traditional workflow is 3D printing of sand moulds and cores — also called binder jetting.

Instead of pressing sand around a physical model, the mould is built layer by layer directly from a digital 3D drawing. A thin layer of sand — typically around 300 micrometers — is spread onto a building platform. A printhead then sprays a binder exactly where the mould or core should be. The platform lowers one layer, and the process is repeated until the entire mould is built up. Finally, the excess, unbound sand is removed, and the finished mould or core can be taken out.

In parallel with digital forming, simulation advances: here the metal is modeled to flow and cool in the mold before the first casting even takes place. This makes it possible to detect risk of e.g. cold connections or gas porosity on screen — and adjust design and gates before real metal and real time is spent on a faulty casting.

• 01Digital tools do not replace professional understanding of metal and form — they build on it
• 02Being able to read a CAD drawing and understand a simulation is becoming an increasingly important part of the trade
• 03Prototypes and small series can be produced faster and more flexibly than before
• 04The basic knowledge of pattern creation, cores and casting defects is still the foundation — technology is a tool to use that knowledge even more precisely

The foundry technician of the future will probably use both the classic sand mold and the new digital tools side by side. The trade is moving, but the core — the understanding of metal, form and process — remains the same.