Siraya Tech introduced a fascinating new foaming 3D printer filament, Flex TPU Air.
Foaming filaments are rare in the industry, but should be more popular due to their incredible versatility. It’s all about flexibility.
When we hear about a flexible filament, we assume it is soft. But how soft, exactly? There are quite a range of hardness levels found in 3D printing, although the mechanics of FFF devices often prevent printing of the softest materials.
For a given 3D print application, one must find the flexible filament that has the right hardness. Sometimes this requires iteration to identify the correct level, meaning you would have to purchase multiple spools of different hardness for testing. That’s expensive.
Enter foaming filaments. The idea here is that there are additives in the material that bubble up when heated as they pass through the hot end of a FFF 3D printer. These bubbles weaken the material slightly, introducing a bit more flexibility.
But it gets better: by varying the extrusion temperature, it is possible to control the amount of bubbles and thereby control the hardness level. This means that a foaming filament can take on any hardness level desired — so long as it’s within the range of the material.
In the case of Siraya Tech’s Flex TPU Air, the material can be anything between 65A and 82A, which is quite a difference in hardness.
This means that one spool of Flex TPU Air is equivalent to having several spools of “fixed hardness” TPU, at least for testing purposes.
There are some other benefits to this material, according to Siraya Tech. One is that the parts printed will have a lower weight. Bubbles don’t weigh much! They say it can be as much as 50% lower than equivalent prints.
They also explain that the surface quality of the prints made with Flex TPU Air has a “smooth, comfortable finish suitable for wearables, grips, and medical accessories”. The bubbling may produce a textured surface, but evidently, it is still smooth.
The material also passes the ISO 10993 certification, giving it a level of biocompatibility.
Like all flexible filaments, Flex TPU Air must be printed quite slowly, up to 12mm/s, according to the manufacturer. This is because fast printing will inevitably cause the flexible filament to accidentally wrap around one of the extruder gears, causing a jam.
As of this writing, Siraya Tech is offering 1kg spools for US$50, only in black.
Alas, they are sold out. Somehow, this is not surprising.
Via Siraya Tech
