I’m looking at a pair of very unusual 3D printers from Pollen.
Pollen is a French company that’s been around for several years developing a different style of 3D printing system that they’ve now deployed in two different 3D printers, one for thermoplastics and one for metals.
Their machine is a delta-style design with a twist: the extruder / hot end does not move; the build plate moves in X, Y and Z directions during printing. This is quite unlike every other delta-style machine I’ve witnessed.
There is an important reason for this non-standard approach: the Pollen system uses pellets instead of filament. It is challenging enough to design a reliable pellet extruder, and even more so if it has to move around the build chamber. Pollen has eliminated part of the issue by having a stationary extruder / hot end system. This allows smooth delivery of pellets to the hot end.
There are two models from Pollen: the Pam Series P and the Pam Series M. The “Pam” no doubt is inspired by “Pellet Additive Manufacturing”, and the “P” and “M” indicate “Plastic” or “Metal”. Yes, one of Pollen’s machines is capable of 3D printing metal.
However, they are both very similar machines in other aspects. For instance, both have an identical build volume of 300mm diameter and 300mm height (delta machines’ volumes require only two dimensions). They both offer a minimum layer size of 0.04mm, suitable for very finely detailed prints. Both offer swappable nozzles ranging from 0.25mm to 0.8mm for more rapid 3D printing operations, although the Pam M includes 1.0 and 1.2mm nozzles as well.
There’s another unusual feature in both machines: they are configured with four nozzles. The Pam P machine is thus able to 3D print up to four different thermoplastic materials in a print job. And what materials might there be? It seems that Pollen has certified quite a few, including: PLA, ABS, PVA, PP, PET, Woodfill, TPU, TPU Soft, TPE Soft, and TPE High Flex.
They also note they’re working on PEEK, PC, POM and PA, all of which require much higher operating temperatures. This strongly suggests they may announce a high-temperature version of the Pam P in the near future, perhaps named the “Pam P HT” or similar.
Because the system can print PVA, a soluble support structure, it should be easy to 3D print highly complex objects on the Pam P device. This feature alone places the Pam P in the professional market, although there are more features that will boost it beyond even that level.
Looking at the Pam M we see that it is also a pellet-fueled 3D printer, but one that produces metal. This means it is capable of handling a wide variety of commonly available MIM (metal injection molding) pellets, which are universally available at very low cost.
The Pam M then simply 3D prints objects using the same thermoplastic approach as done in the Pam P. However, after printing a MIM approach is undertaken. The “green” prints are first treated with a chemical to eliminate all the MIM binder material, leaving just the metal particles in the correct geometry. This creates a “brown” part that can be sintered in any furnace to create a fully solid 100% metal part. This type of process is used by several other recent metal 3D printer manufacturers, including Desktop Metal and Markforged.
One extremely interesting feature is that the Pam M device also includes four nozzles. However, due to the mysteries of MIM materials, you can’t really mix different materials. But you can install four differently-sized nozzles. This means that the Pam M can, for example, use a fat nozzle for printing unseen infill material quickly, yet use smaller nozzles for exterior fine details.
However, Pollen has a significant advantage because they are able to utilize standard MIM materials, unlike some other systems that require the use of much more expensive proprietary MIM-like materials. Producing metal parts on the Pam M should be extremely inexpensive when compared to any other metal 3D printing system.
The same is true of the Pam P; pellets are significantly less expensive than filament. In fact, filament manufacturers use pellets as their raw material, and so if you use pellets directly, you are literally cutting out the middleman and reducing expense, time and energy.
Pollen has realized their advantage and is portraying it as a way to achieve “low” volume production with their equipment. I put “low” in quotes because it really isn’t low. Previous instances of “low volume manufacturing” I’ve seen typically talk about unit qualities in the dozens or hundreds, but Pollen talks about tens of thousands. Check out this chart they prepared as an example of the pellet cost effect:
This moves the “line of 3D printing” far higher than it’s ever been previously, and would open up all manner of manufacturing possibilities. The same effect is seen on their Pam M machine.
Pollen prepared this fascinating chart to illustrate how their “high volume” 3D printing system could fit into the lifecycle of a manufactured product:
As you can see, Pam technology would be used at the beginning and the end of the lifecycle, but not in the middle when, perhaps, millions of products are produced. That’s still best done by traditional approaches. But there’s that line I mentioned. It just moved to the right quite a bit.
It seems to me that the Pollen strategy is a good one: offering a machine that can truly be financially effective in manufacturing. The only catch is that their equipment has a relatively small build volume. However, if the concept catches on, then perhaps bigger machines could be produced.