Bambu Lab TPU for AMS Filament 1.75mm 1kg

The flexible filament you can actually run through an AMS. Ordinary TPU is too soft and too grippy to survive a multi-material feed path — it buckles in the tubes and jams. Bambu reformulated this one at 68D on the Shore scale, firm enough to push reliably while still bending, so multi-colour and multi-material flexible prints finally work unattended.

Think phone cases, watch straps, grips and tool handles, protective bumpers, printed hinges, seals and machine feet — anything that needs to give a little, in more than one colour.

It also prints much more like PLA than TPU usually does: minimal stringing, no crawling speeds, and a 250 mm/s ceiling that most flexibles come nowhere near.

At a glance

Note the low bed temperature

30–35°C, not 60. This catches people out. TPU sticks to a warm plate hard enough that you can tear the PEI surface getting the part off. Run the bed cool, use glue as a release layer, and let the plate come back to room temperature before you lift anything.

What the numbers say

Impact strength is 124.3 kJ/m². For comparison, PETG Basic is 34.2 and ABS is 39.3. It does not break — it absorbs and springs back. Breaking elongation is over 650%, meaning a test bar stretches to more than seven times its length before parting.

Tensile strength is 22.4 MPa and stiffness 1190 MPa, both low by rigid-plastic standards — but that is the point. You choose TPU when you want the part to give.

Layer bonding is the one thing to watch. Elongation across layers drops from 650% to 31%, and tensile from 22.4 to 11.2 MPa. A flexible part that gets stretched across its layer lines will split long before the material's headline flexibility comes into play. Orient so the stretch runs along the layers.

Worth knowing

Cooling fan on, supports on. Both are specified by Bambu for this material.

Not resistant to acids or alkalis, but it does resist most oils and greases — useful for gaskets and machine feet.

Storage

Bambu specifies under 20% RH, sealed with desiccant, and 70°C for 8 hours to dry.

TPU absorbs 1.20% water — more than any other material we stock, roughly double ABS. It takes on moisture quickly once opened, and wet TPU prints badly in an obvious way: popping, foam-textured surfaces and weak layers. Keep it sealed between prints rather than leaving it on the machine.