Smooth TPU added to Markforged Material Library

Markforged has officially launched their Smooth TPU (S-TPU) today. So, you can now print flexible, soft and squeezable parts the Markforged way!

 

What is Smooth TPU?

TPU (Thermoplastic Polyurethane) is one of a few elastomeric materials capable of printing on an FFF 3D printer. It is a highly flexible and soft material that can stretch more than 5x its original shape before failing.

Because it is a soft, flexible filament, TPU is known within the industry as a very challenging material to print. Through excellent materials and systems engineering work, Markforged printers can now print this elastomeric material with excellent surface finish and reliability.

 

Smooth-TPU Vs Onyx™

S-TPU is great for functional parts that require flexibility. With >500% elongation to break and a 95 ShoreA hardness, Smooth TPU can be used to replace rubber-like parts for our customers. In comparison to Onyx, S-TPU provides properties on the opposite side of the spectrum. Trading rigidity for flexibility and strength for elongation.

Because of the flexibility and softness of TPU filaments, it is a very challenging material to print through a Bowden tube system. However, through excellent engineering work, Markforged has accomplished a very smooth surface finish on this material. Users can expect best-in-class print reliability with part quality on par or better than our TPU competitors.

In comparison to Onyx, users can expect occasional strings of filament that can be manually pulled off a part after print. When strings are present, it is most commonly found between the part and the TPU Purge Tower (a small circular tower at the back left of the print bed that is used to maintain consistent back-pressure in the system). If there are a lot of strings in a print, it is likely either an extrusion issue that can be fixed by using the Composite Purge Kit and/or bed levelling.

 

When should I use Smooth TPU vs. Onyx

When to use Smooth TPU?

• Printing parts that require flexibility (like drive belts)
• Printing parts that need to be soft (like bumpers / protective coverings on a manufacturing floor)
• Printing parts that need to be squeezed between gaps of components without damaging them (gaskets)

When to use Onyx

• You want to add continuous fibre
• You’re looking for the best-possible surface finish
• You plan on subjecting the part to moderate to significant heat and functional loads.