voxeljet’s Thermoplastic Strategy Unfolds Further with TPU and PP Materials

The latest news from voxeljet suggests the company is going full power towards a thermoplastic strategy.

The company, well known for its very large 3D printers, is one of the few that are publicly traded. Unfortunately the company’s stock price collapsed in 2014-15 along with most other 3D printer stocks, but still has not recovered. Their recent moves appear to be a strategy to overcome that issue, and it could definitely be a winning strategy.

Traditionally voxeljet’s technology has been used for 3D printing large-scale industrial molds in sand or sand-like materials. These would be used to cast metal or other materials into large objects by several industries.

As useful as that process may be, it does restrict voxeljet’s sales to certain market segments, which may be one of the factors contributing to their lower stock price.

The company has embarked on a new 3D printing process they call High Speed Sintering (HSS), which could open up a great many possibilities for future applications. HSS leverages their existing equipment designs, yet allows for the 3D printing of many more types of materials.

They explain HSS:

“In the HSS process, a thin layer of plastic granulate, such as PA12 or TPU, is applied on to a heated building platform. An inkjet print head then moves over the entire surface of the platform and moistens the areas of the construction site with infrared light-absorbing ink, on which the prototype is to be produced.

The building platform is then irradiated with infrared light. The wetted areas absorb the heat, which sinters the powder layer underneath. However, the unprinted powder remains loose. After sintering, the building platform is lowered by one layer thickness. This process is repeated until the assembly of a component is completed.

The sintered parts are then cooled down in a controlled manner in the installation space before they can be removed and unpacked. In contrast to laser-based processes, the entire building platform can be printed in just one go, which enables a constant layertime time, irrespective of the size and complexity of the parts.

Inert gas atmosphere is also not necessary for the HSS printing process. The large-area print head has a resolution of 360 dpi achieved through 3000 individually controllable nozzles, which allows the smallest details to be manufactured with high precision of the edges.

In combination with a minimum layer thickness, the resolution of the print head enables the production of the finest structures with wall thicknesses of up to 0.15 mm. Since the HSS printing process requires no other fluids than ink, material costs can also be reduced to a minimum. The high quality of the components is also underlined by high accuracy and impressive definition of the edges.”

This means that the voxeljet equipment, when configured with the HSS feature, would be able to 3D print in almost any thermoplastic powder, and do so quite rapidly. The speedy print process is especially important for the large-sized prints that voxeljet’s equipment produces.

How large? Their smallest machine, the VX200, is 300 x 200 x 150 mm, while their largest machine, the massive VX4000, listed as “The World’s Biggest Industrial 3D Printer”, sports a titanic build volume of 4,000 x 2,000 x 1,000 mm.

If and when voxeljet enables their HSS feature on the VX4000, we then have a machine that can quite literally 3D print truly gigantic objects in popular thermoplastic materials.

Last week the company announced they’ve made significant progress testing two such popular materials, polypropylene (PP) and TPU. PP is frequently used in prototyping due to its engineering properties and overall versatility, particularly its resistance to chemicals. I can imagine it being used to produce, say, large and unusual fluid conduits with the HSS process.

TPU is a flexible material, and this presents all sorts of interesting possibilities. Imagine being able to 3D print very large flexible objects: what applications are possible? Giant gaskets? Entire tires with custom tread patterns for huge equipment?

The nylon materials that are also possibly used in HSS are also quite interesting. One notion that crosses my mind is the ability to 3D print fashions at a large scale. Typically 3D printed fashions involve tiny interlocked cells, and producing large pieces on smaller 3D printers is challenging as the 3D model must be “folded” to fit. That won’t be a problem on the HSS machines. In fact, one could imagine multiple sets being printed in a single job run.

All these possibilities make prospects for voxeljet very interesting. I believe the HSS capabilities should open up many new opportunities for the company, just as they have for the few other 3D printer companies that have pursued large formats. They found strong niche markets, and so can voxeljet.

voxejet hopes to release HSS in late 2019.

Via voxeljet