What is Selective Heat Sintering (SHS), and how does it work?

Blueprinter M3 Selective Heat Sintering

There are several different 3D printing processes found within 3D printers. The most well-known process is Fused Filament Fabrication (FFF), with Stereolithography (SLA) not far behind.

Selective Heat Sintering (SHS) is a less well-known 3D printing process than Fused Filament Fabrication or Stereolithography, in large part because it has been adopted by a single 3D printer manufacturer – Blueprinter.

A Danish company, Blueprinter invented and patented Selective Heat Sintering technology early on in their history when they were just a startup. The idea for Selective Heat Sintering technology came from the company’s founders, Frederik Tjellesen and Anders Hartmann, who had the backing of Seed Capital with an investment of more than €150,000 .

SHS printed part

The technology was launched at Euromold in 2011 to much fanfare. Blueprinter started shipping their first 3D printer, the Blueprinter, shortly afterwards. They updated their product with the user-friendly Blueprinter M2 in 2014 and in 2015 they launched their latest 3D printer, the Blueprinter M3, which is more powerful than the M2 and 60 per cent quieter.

Unlike Fused Filament Fabrication, Selective Heat Sintering is a specialised 3D printing process with powder-based 3D printing technology suited to applications where complex geometries are demanded. The actual process itself is far less complicated than you might think, however, so here’s everything you need to know about Selective Heat Sintering:

What is Selective Heat Sintering?

SHS print example

Selective Heat Sintering is an additive manufacturing process akin to Selective Laser Sintering. However, the two processes should not be confused. SHS uses a thermal print head to sinter thermoplastic powder, while Selective Laser Sintering uses a laser to sinter thermoplastic powder. The benefits to using a thermal print head over a laser are twofold: 1) The 3D printer can be much smaller and similar in size to larger mainstream desktop 3D printers, and 2) The 3D printer can be a lot cheaper, because thermal print heads are far less expensive to purchase than lasers are.

How does Selective Heat Sintering work?

The Blueprinter M3 spreads a thin layer of thermoplastic powder (the latest version of this thermoplastic powder is called M-Flex) across its build chamber, or print bed, where the powder is held at a slightly elevated temperature. The printer’s thermal print head then moves back and forth across the powder bed and melts cross-sections of the powder into a layer of solid plastic. Once a layer is complete, the 3D printer repeats this process to build a 3D object layer-by-layer. The finished model is then pulled from the build chamber by hand, and any unused thermoplastic powder can be reused. You can also print multiple parts at once with the Blueprinter M3.

Is there a benefit to Selective Heat Sintering over FFF?

The biggest benefit for engineers and designers is that Selective Heat Sintering builds a 3D object without the need for any support structure whatsoever. And as a result, this technology gives you freedom to build almost any shape you like; or to put it another way, you can 3D print parts and models that you simply wouldn’t be able to with a Fused Filament Fabrication or Stereolithography 3D printer. In addition to this, the thermoplastic powder used by the Blueprinter M3 (M-Flex, which is an unpigmented white powder) when printed is very similar to nylon. Parts are strong and durable with an ultimate tensile strength of 7,5 Mpa. This makes SHS an ideal 3D printing process for creating functional prototypes.

How complex can models get? And are prints consistent?

Models can get very complex. The Blueprinter M3, as discussed, works by applying heat on layers of thermoplastic powder (polyamide). This allows for the free forming of any complex shape, so long as it has a minimum wall thickness of 1mm. Shapes can be far more complex than any FFF or SLA 3D printer can produce. In terms of part-to-part consistency, you can print multiple parts at a time with the Blueprinter M3 and having tested this printer and seen it used within demanding design environments, we can honestly say that consistency is excellent from part to part. Parts are printed cost-effectively too, with the M3 offering one of the lowest total cost of ownership rates on the market.