filament.swatchThe Workbench Reference
TPU PART #NINJATEK·NINJAFLEX·TPU

NinjaTek NinjaFlex TPU

Manufactured by NinjaTek

DATASHEET · MEASURED VALUES
MATERIAL TPU
DIAMETER 1.75 mm MEAS. ± 0.02 mm
NOZZLE TEMP 225 235 °C
BED TEMP 20 40 °C
SPOOL 500 g
WARPING none
MOISTURE high
8.4 /10 RANK 0 / 2
PRINTABILITY 6/10
LAYER ADHESION 10/10
SURFACE FINISH 8/10
STRINGING RESIST. 4/10
BED ADHESION 8/10
VALUE FOR MONEY 8/10
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REVIEW NOTES

Quick Summary

This NinjaTek NinjaFlex review covers the filament that defined flexible printing. At 85A shore hardness with roughly 660% elongation, it is genuinely rubber-like — squishy, bouncy, and tough. That softness is its superpower and its challenge: it makes superb gaskets and grips, but it needs a direct-drive extruder and a slow hand.

NinjaTek lists 225–235 °C at the nozzle with a room-temp to 40 °C bed; painter’s tape or glue helps adhesion. The decisive setting is speed — keep it slow, roughly 10–35 mm/s. Soft filament buckles under fast feed pressure, so patience here is what separates clean prints from jams.

Layer adhesion is outstanding and finished parts are durable, elastic, and great at damping vibration. The low-tack surface texture feeds better than older flexibles, but it remains demanding. Stringing can appear because the material is hygroscopic — dry it before critical prints.

Where It Falls Short

It is hard to print on Bowden setups, slow to run, and sold in smaller 0.5 kg spools that raise the effective price. Beginners and indirect extruders will fight it.

Verdict

When you need true rubber softness — seals, wearables, dampers — NinjaFlex is still the benchmark. For easier, faster flexible parts that just need to bend, a firmer 95A TPU is the saner choice.

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COMPARE
  • NinjaTek NinjaFlex TPU vs sunlu tpu 95a — SUNLU TPU 95A is firmer, faster, and far easier to feed; NinjaFlex is much softer and more rubber-like for gaskets and wearables that need genuine squish.
FAQ
How flexible is NinjaFlex?

Very. At 85A shore hardness with around 660% elongation, it is rubber-like — far softer than typical 95A TPU. That makes it ideal for gaskets, grips, and wearables, but it needs a direct-drive extruder to feed reliably.

What temperature should I print NinjaFlex at?

Print at 225–235 °C with the bed from room temperature up to 40 °C. The key is speed: keep it slow, around 10–35 mm/s, so the soft filament does not buckle or jam in the extruder.

Can I print NinjaFlex on a Bowden printer?

It is difficult. The long Bowden path lets soft 85A filament compress and kink. A direct-drive extruder is strongly recommended; on Bowden, expect jams and inconsistent extrusion.

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