TPE vs TPU: polymer families, hardness and printer requirements

What the word TPE actually covers on a spool

The Prusa knowledge base states the ground rule: flexible filaments are TPE, thermoplastic elastomers, but they are sold under various names such as TPU or TPEE. TPU, thermoplastic polyurethane, is therefore a subtype of the TPE family. When a label only says TPE, it names the family without specifying the chemistry. When it says TPU, it names one specific chemistry inside that family.

The Polymaker wiki agrees on the hierarchy and defines TPU as a flexible thermoplastic elastomer. Yet the same wiki includes a comparison table where TPU and TPE sit in separate columns. There, TPE gets higher elasticity, moderate durability, moderate chemical resistance and challenging printability, while TPU is listed with high elasticity, excellent durability and moderate printability.

The two pages use TPE in different ways: Prusa calls TPU a TPE subtype, while Polymaker places “TPU” and “TPE” in separate columns without defining the composition of its TPE entry. That table does not establish that TPE always means a non-polyurethane polymer. Check the exact chemical name and product properties on the specific datasheet. The TPU filament guide covers one grade in this family.

Shore hardness: what it measures and what it leaves out

Prusa gives a usual TPU hardness range around 60A–90A in its general guide. Keep that as the guide's indication, rather than a definition or an exhaustive interval for every commercially available TPU. Polymaker links lower Shore values to softer material and also notes infill's effect on part flexibility. Distinguish the stated material property from the behavior of the printed object, to which geometry also contributes. Changing the infill does not change the spool's stated material hardness.

Elongation figures and descriptions of oil or abrasion resistance need to remain attached to a reference and its test conditions. Polymaker's general guide discusses these properties for TPU without comparing two identified grades at equal Shore hardness here. To prepare that comparison, record the measured property, method and specimen condition from the actual product sheets. Do not substitute the TPE or TPU family name for those data. This separates a material description from a documented result under specified conditions.

Two filaments with the same hardness can differ, but these pages do not compare products at identical Shore values. Prusa only says that softer flexible filaments are generally harder to print. To compare two grades, consult their own datasheets and test conditions; hardness alone is not a complete ranking. See TPU 95A vs 85A for that specific angle.

Read the datasheet, not the marketing name

To prepare a purchase, we suggest four checks: chemical base, Shore hardness with its scale, temperature ranges and extruder recommendations. This checklist organizes your research rather than defining a documentation requirement for every sheet. If a needed characteristic is absent from the product page, find the full documentation or ask the manufacturer. A value missing from one excerpt does not establish that it is unpublished elsewhere. Keep the exact reference with your notes so similarly named products are not combined.

Documented ranges differ between sources, which is exactly why you should read the sheet for your specific filament. Prusa recommends a nozzle between 230 and 245 degrees Celsius depending on hardness and brand, and a bed between 60 and 75 degrees, with larger objects tending toward the top of the range. Polymaker lists 210 to 250 degrees at the nozzle depending on brand, starting at 230, and 40 to 60 degrees for the bed.

The published ranges differ; they are general guidance on these pages, not a substitute for the specific product datasheet. Polymaker says its requirements depend on the TPU blend. If the available product page omits a needed property, look for the full product documentation or ask the manufacturer; do not infer that no such document exists.

Printer compatibility: what to check for real

Polymaker's guide prefers direct drive and says soft TPU can be difficult for Bowden systems. It also recommends an all-metal hotend above 240°C. Keep these as that general guide's instructions, then check the published limits of your printer's exact setup. A material name alone cannot validate every filament path, extruder or hotend temperature. The actual machine and its supported materials need to match the intended grade and settings.

Prusa's documentation shows how limits vary per machine. It notes that the Original Prusa XL has a long path from loading to the nozzle, so soft filaments need special care, and a printable flexible filament bypass exists. The CORE One+ and CORE One L have a switch on the side filament sensor housing that loosens the lever to ease loading.

Prusa warns that automatic filament changes may not work properly with flexibles. An older support comment about one configuration would not by itself establish the current state of every system. Check the documentation for the actual setup and spool; the TPU for AMS page provides a starting point for that check. Keep any stated restriction attached to the named hardware generation and material rather than extending it to every flexible filament.

Starting settings documented by manufacturers

Both sources publish speed ranges in their general guides. Prusa states that a typical speed for flexibles is 20 mm/s, with a recommended maximum between 30 and 40 mm/s, beyond which the nozzle may clog or the filament may tangle in the extruder gears. Polymaker gives 15 to 40 mm/s, describing slower speeds as helping prevent filament buckling, particularly for softer grades.

Prusa advises loosening the idler so the gears push the filament gently; for retraction, its guide suggests turning it off and then increasing it gradually while observing the result. Polymaker publishes 1–2 mm at 10–20 mm/s for its TPU guide. Treat these as separate guidance from each source to check against the exact grade and printer profile, not as one universal setting.

On cooling, the advice differs and again illustrates how formulations vary. Prusa recommends keeping the print fan off and raising the nozzle by 5 degrees to reduce filament resistance. Polymaker suggests 20 to 50 percent fan to balance detail and layer bonding, with a 0.2 to 0.3 mm layer height. Start from the profile published for your exact filament in your slicer, then adjust from there.

Moisture, supports and adhesion: pitfalls shared by both families

Prusa classifies the flexible filaments covered on its page as hygroscopic. Polymaker recommends a dry box and pre-drying at 50 °C for 24 hours for the TPU covered in its guide. This does not establish that every formulation labeled TPE uses the same drying routine: follow the instructions for your spool.

Bed adhesion also depends on the material and surface. Prusa says its high-adhesion note applies to TPU and TPEE; for some very soft flexible materials, it recommends a separating layer on smooth or satin sheets. Polymaker also recommends a glue stick as a release agent in its TPU guide. Check the exact grade and surface before applying this advice.

Prusa says supports can be difficult to remove with the flexible materials it covers and gives starting distances for its settings; Polymaker also describes removal as often difficult for TPU. Polymaker lists stringing among TPU challenges, while Prusa lists it for flexible filaments on its page. These tips do not guarantee results for a particular profile.

Sources and limits

• Prusa Knowledge Base — flexible materials, general guide and printer notes
• Polymaker Wiki — TPU, general printing guide and terminology

We organize manufacturer and community documentation; we have not measured these products ourselves. The manual for your exact model takes precedence over general guidance.