Danko Arlington Inc — based in Baltimore and the American Foundry Society’s Metalcaster of the Year — recently installed its first 3-D sand printer.

Designed and made by the German company Voxeljet, the new VX1000-PDB is the first of its kind in the USA.

PDB stands for phenolic direct binding, which uses a 600dpi print head to selectively eject glue onto a thin bed of sand.

The application of infra-red heat then cures the glue to build up a solid sand mould, layer by layer.

After printing, any unbound sand is recycled; and after metal casting, the solid PDB sand moulds can be crushed and thermally reclaimed in Danko Arlington’s sand recycler.

The additive process eliminates the need for a die or pattern to create a mould cavity, allowing engineers to design metal castings on a computer and then have the printer make the sand moulds automatically.

With 3-D sand printing, molten alloys can be poured to custom shapes within hours, instead of waiting — often weeks — for traditional tooling to be made.

For years, the VX1000 has been a proven platform for printing plastic models and moulds for the investment casting process using PMMA (Poly-methyl meth-acrylate) material.

With the machine now adapted for sand, printing layer thicknesses of about 300µm (0.012in) will allow for particularly high accuracies.

The machine’s printing envelope of 1000 x 600 x 500mm allows for the quick production of medium-size components, functional prototypes and complex sand cores.

Danko Arlington has recently renovated about 5,000ft² of its pattern shop to house this new equipment.

The company’s new Additive Manufacturing (AM) centre will also house two large Stratasys Fortus 900mc 3-D printers, which have been producing polycarbonate patterns and core boxes since 2010.