PEBA 95A Polyether block amide, Shore 95A (PEBA 95A)

PEBA (polyether block amide) is a thermoplastic elastomer built from alternating blocks of two polymers: rigid nylon (polyamide) segments that give it toughness, and soft polyether segments that give it rubbery stretch. QIDI describes it as blending the toughness of nylon with the elasticity of an elastomer. It's the same family of material used in many high-end running-shoe midsoles, which is the best clue to what it's good at.

The headline difference from TPU is resilience, also called energy return: how much of the energy you put into squashing the material comes back when it springs out. QIDI quotes 70 %+ energy return for PEBA, against 50–60 % for EVA foam, and says it snaps back with very low hysteresis (little energy lost as heat on each squeeze). In a printed part that shows up as a lively, bouncy feel where TPU feels more damped and “dead”.

PEBA is also light. QIDI's PEBA 95A has a density of 1.01 g/cm³, versus 1.20–1.24 g/cm³ on Polymaker's TPU 95A data sheet, and QIDI says it is over 12 % lighter than standard TPU 95A. At the same 95A Shore hardness (the rubber hardness scale explained on our TPU 95A page), the two materials feel similarly firm in the hand; the difference is in rebound, weight and cold-weather behavior.

The trade-offs are cost and printability. PEBA filament is priced well above TPU, it must be dried thoroughly, it is fed from an external spool rather than the QIDI Box, and its supports are hard to remove because it bonds strongly to itself. For most bumpers, grips and seals, TPU 95A does the job for less; PEBA earns its premium where energy return, weight or cold flexibility really matter.

QIDI's data show PEBA 95A is tough rather than strong in a rigid-plastic sense. It lists a tensile breaking strength of 32.58 MPa in the XY plane and an elongation at break of about 1107 %, so a printed strip stretches to many times its length before it fails. Charpy impact specimens did not break at 23 °C, which is what you'd expect from an elastomer.

Its standout figure is tear strength across layers: QIDI reports 86.22 kN/m in the Z direction (the direction across the stacked layers, which is usually the weak one in FDM). That fits QIDI's note that PEBA's layer adhesion is strong. FDM parts still behave somewhat differently along and across layers (anisotropy), so we orient stretched or flexing features to load the layers along their length where possible.

As with any flexible, the feel of a PEBA part depends heavily on geometry. Wall count, infill pattern and density, and lattice design set how soft and springy it is, which is why PEBA is popular for printed lattice cushions where the structure is tuned zone by zone. Under constant squeeze it will still creep and take some set over time, so seals and load-bearing pads should be designed with moderate compression.

PEBA sits low in our heat ratings, alongside TPU. QIDI lists a Vicat softening temperature of 102.8 °C, which is the temperature at which a small loaded needle sinks into the material a set distance. That number is higher than many people expect for a rubber, but a flexible part softens and loses springiness progressively as it warms, long before it reaches its Vicat point, so don't read it as a working temperature.

Cold is where PEBA shines. QIDI says it keeps its flexibility and impact resistance down to −40 °C, while many flexible materials stiffen and become brittle in hard frost. If your part has to flex in winter outdoors or in a freezer, PEBA is worth the premium over TPU.

QIDI doesn't publish UV data for PEBA 95A. As a general rule, elastomers that aren't specifically UV-stabilized discolor and gradually lose surface flexibility in strong sunlight, so we rate PEBA as middle-of-the-road for UV. For long-term outdoor service choose black, keep sections reasonably thick and plan for replacement; if the part does not need to flex, ASA is the better outdoor material.

QIDI says PEBA 95A resists oils, greases and industrial alcohols, which suits grips and pads that see hand oils, sunscreen or cleaning wipes. Polyamide-based materials generally hold up well to fuels and many oils too, but resistance varies by grade and exposure.

Strong acids, strong solvents such as acetone, and brake fluid are not covered by QIDI's data. If your part will be soaked or wiped with a specific chemical, send us the product name and we'll suggest a soak test on a sample before a production order.

PEBA is hygroscopic (it absorbs moisture from the air), with a water absorption of 1.56 % listed by QIDI, and its nylon segments make it more moisture-sensitive than TPU. Damp filament bubbles during printing and, in QIDI's words, severely weakens the part, so we dry it before every job and print it straight from a dry box. QIDI ships it in vacuum foil packaging for this reason.

Finished parts in humid air or occasional water contact remain usable, though like nylon they may change feel slightly as they take up moisture. Long immersion is not recommended without testing.

PEBA prints with a satin, slightly rubbery surface and visible layer lines, similar in look to TPU. Fine stringing between features is common with flexible filament and is removed during cleanup.

Its strong layer adhesion is good for strength but bad for supports: they bond firmly and leave rough witness marks. QIDI recommends larger support gaps, sparse supports and a PLA interface layer when supports can't be avoided, and we prefer to orient parts so they print without them.

There is little post-processing to do, and not much that can be done. PEBA doesn't sand cleanly, paint tends to crack when the part flexes, and vapour smoothing is not something we offer for this material. Annealing is listed by QIDI as not recommended.

We trim strings and support marks by hand. For fastening, design in captured nuts, clamping features or bonded rigid inserts, because heat-set inserts and printed threads hold poorly in a flexible material.

Expect looser tolerance than with rigid materials. Elastic stretch during extrusion, slight bulging and rounded corners make tight fits hard to hold, and holes generally print a little undersized. For press fits, start with a test print at two or three interference values.

Measure flexible parts in use rather than free on the bench: a cushion under load or a sleeve stretched over a handle behaves differently from the part sitting on a table.