TPU Filament Temperature Guide: Nozzle & Bed Settings by Shore Hardness
The right TPU filament temperature is the difference between a glove-soft print that comes off the plate clean and a stringy, under-extruded mess with layer gaps you can slide a fingernail into. We print flexibles weekly across both bowden and direct-drive machines, and nozzle temp is the one setting that trips newer users up first.
This guide covers starting points by shore hardness (85A versus 95A), bed and surface ranges, extruder style, and a troubleshooting table that maps symptoms to fixes. Pair it with dry filament and modest speeds and you will spend almost no time chasing ghosts.
TPU filament temperature at a glance
Most TPU prints cleanly between 220 and 240 degrees Celsius at the nozzle, with the bed anywhere from 40 to 60 degrees. Chamber temperature is optional below 95A but helps keep layer adhesion consistent on tall or thin-walled parts.
The table below is the quick reference we hand to new team members. Treat it as a starting point and move 5 degrees at a time.
| Shore hardness | Nozzle (°C) | Bed (°C) | Typical speed | Notes |
|---|---|---|---|---|
| 85A (very soft) | 230–245 | 50–60 | 15–25 mm/s | Direct drive only; buckles in bowden |
| 90A | 225–240 | 45–55 | 20–30 mm/s | Sweet spot for grips and seals |
| 95A | 220–235 | 40–55 | 25–40 mm/s | Prints like stiff plastic; most forgiving |
| 98A (semi-rigid) | 220–235 | 40–50 | 30–50 mm/s | Treat as PETG with retraction tuning |
Numbers assume a 0.4 mm nozzle, dried filament, and part-cooling fans at 30 to 50 percent. If you are on a 0.6 mm nozzle or printing a thick-walled part, nudge the nozzle 5 to 10 degrees warmer and drop the fan to compensate.
How shore hardness (85A vs 95A) changes your temperature window
Shore hardness is a direct read on how soft the finished print will be, and it also predicts how much heat and patience the filament needs. 95A behaves close to a soft PETG, while 85A is squishy enough that the extruder gear can carve a notch into the filament if you push it fast or cold.
Softer TPU prints hotter and slower for two reasons. First, the melt viscosity is higher at a given temperature, so you need more heat to get clean flow through the melt zone. Second, the filament itself is less column-strong, so faster speeds translate into the strand bulging between the extruder and the nozzle instead of pushing melt out.
With 95A you can usually start at 230 degrees and 30 mm/s and dial from there. With 85A, start at 235 to 240 and keep the first wall under 20 mm/s. Infill and inner walls can run faster, but the outer visible walls set the surface quality and should stay slow.
Retraction behaves differently too. Softer TPU rebounds like a rubber band, so long retracts cause under-extrusion on the next line instead of fixing stringing. Shorter retraction (0.5 to 1.5 mm on direct drive) with slightly higher travel speed will outperform aggressive 4 mm retracts almost every time.
Recommended nozzle and bed ranges for popular TPU grades
Published specs vary and most spools arrive with a sticker range that is wider than what prints cleanly. These are the starting points we use after dialing each spool in, not what the manufacturer paints on the box.
Premium 95A TPU typically prints well at 230 degrees nozzle and 45 degrees bed on textured PEI. The listed range is usually 220 to 240, but 230 is where stringing and layer adhesion both sit in the quiet middle on most modern enclosed printers. A 235-degree first layer for one or two layers helps if your plate is older.
Eryone TPU 95A runs a touch cooler, around 225 to 230 degrees. It is slightly less melt-viscous than typical blends, so dropping in at 235 can give you wet-looking surfaces and oozing on travels. Bed at 50 degrees, textured PEI, no glue.
For generic or shop-brand 95A TPU, 228 degrees is a safe default. Softer 85A and 90A spools from mid-range makers typically want 235 to 240 at the nozzle and 55 at the bed. If the first layer squishes but will not stick on corners, raise the bed 5 degrees before touching the nozzle.
One habit that has saved real time: when a new spool goes on, print a 20 mm temperature tower from 220 to 245 before committing to a big part. Twenty minutes of calibration beats a four-hour failed print.
Bowden vs direct drive: tuning TPU temperature for your extruder
Bowden setups push the filament through a long PTFE tube between the extruder and the hotend. For stiff plastics this is fine. For TPU, that tube acts like a spring, and anything softer than 95A will buckle inside it the moment you push flow faster than the melt zone can accept.
Running higher nozzle temperatures is how you fight back. On a bowden printer we add 5 to 10 degrees over the direct-drive starting point and drop volumetric flow to about half. A 95A spool that prints happily at 225 on a modern direct-drive machine may want 235 on an older bowden setup with a stock hotend. The Prusa TPU printing guide covers the mechanical constraints well if you want deeper reading.
Speed is the other half of the fix. Keep print speed between 15 and 25 mm/s on bowden and lower retraction to roughly 2 mm. Longer retracts just stretch the filament inside the tube without actually pulling melt back from the nozzle.
Direct drive is the easier mode. The short, rigid path between gears and melt zone means you can run cooler, retract less, and push speeds into the 30 to 40 mm/s range on 95A without ghosting or gaps. If you print TPU often, a direct-drive conversion pays for itself in reduced print time and fewer failed overhangs.
Bed temperature, build surface, and first-layer adhesion
TPU sticks aggressively to the right surface and refuses to sit on the wrong one. The goal is a plate tacky enough to hold the first layer flat while cool enough that the part releases when the bed drops back to room temperature.
Textured PEI at 45 to 55 degrees is the quiet winner for 95A. Fifty is the sweet spot for most mainstream and shop-brand spools. First layer at 55, subsequent layers at 50, part pops off clean once the bed is below 30.
Smooth PEI is grippier and needs less heat. Forty to 45 degrees is usually enough; above that, TPU can fuse to the sheet and tear a plug of PEI out on removal. If you only have smooth PEI, lay a thin coat of water-based glue stick as a release layer. It also protects the sheet from the softer 85A grades.
Glass is the hardest surface for TPU because the thermal mass holds heat long after the print finishes. If glass is what you have, set the bed to 50, use glue stick, and wait for the bed to drop below 25 before pulling. Blue painter's tape is a passable alternative but will tear on removal.
TPU troubleshooting: stringing, under-extrusion, and layer separation
Most TPU print problems trace to three variables: moisture, speed, and retraction. Temperature is the fourth, not the first. Our full 3D print troubleshooting by material: PLA, PETG, ABS, TPU guide covers symptoms across every common filament; the table below is TPU-only and points at the single setting that most often clears each symptom.
| Symptom | First thing to try | Second thing to try |
|---|---|---|
| Thick stringing between parts | Dry the spool 6 hours at 50°C | Raise nozzle 5°C, cut retraction to 1 mm |
| Fine hairy stringing | Lower nozzle 5°C | Raise travel speed to 150 mm/s |
| Under-extrusion mid-print | Drop print speed to 20 mm/s | Raise nozzle 5°C |
| Gaps between layers | Raise nozzle 5°C | Lower part cooling to 20% |
| First layer peels in corners | Raise bed 5°C | Clean plate with isopropyl alcohol |
| Part fused to plate | Lower bed 5°C | Wait for plate to drop below 25°C |
| Soft blobbing on surface | Dry the spool, then lower nozzle 5°C | Lower flow to 97% |
Moisture is the one setting most people skip. TPU is hygroscopic enough that an open spool in a humid shop can be audibly cracking at the nozzle within 48 hours. If a brand-new spool strings on its first print, it was already wet when it reached you.
Retraction tuning deserves its own pass once temperature is settled. Start at 1 mm on direct drive, 2 mm on bowden, and raise in 0.5 mm steps until stringing stops. Longer than 3 mm on TPU rarely helps and often introduces the under-extrusion in column four above.
Dry filament, print speed, and other variables that shift your temperature
Every number above assumes dry filament. A wet spool at 230 degrees prints like a dry spool at 215: popping, under-extruded, bubbly surfaces. Before you blame temperature, run the spool through a dryer at 50 degrees for six to eight hours. We keep a dryer running next to each flexible-material printer so freshly opened spools get a dry cycle before their first print.
Print speed and temperature trade against each other. A 95A spool at 30 mm/s may want 225 degrees; the same filament at 50 mm/s probably needs 232. Volumetric flow is what the hotend actually sees, and faster feed means more cold filament hitting the melt zone per second.
Part cooling matters more than it does on PLA. TPU below 90A benefits from reduced cooling (20 to 40 percent) on the outer walls so layers have time to weld. Thin tall parts in 85A often fail cold at full fan and succeed at zero fan with no other changes.
Nozzle size compounds everything. A 0.6 or 0.8 mm nozzle moves more volume per second and needs a corresponding bump in nozzle temperature, usually 5 to 10 degrees. Smaller 0.2 mm nozzles rarely play well with soft TPU and we avoid them for anything below 95A.
FAQ
What is the best nozzle temperature for TPU filament?
Most TPU prints cleanly between 220 and 240 degrees Celsius at the nozzle. Start at 230 for 95A and 235 to 240 for softer 85A, then adjust in 5-degree steps based on stringing and layer bonding. If you are on a bowden printer, add another 5 to 10 degrees on top of those starting points.
Temperature towers are the fastest way to nail the window for a specific spool. Twenty minutes of calibration beats guessing on a four-hour print.
Do you need a heated bed for TPU?
A heated bed is not strictly required for TPU, but it is the easiest way to get a clean first layer. Forty to sixty degrees Celsius on textured PEI gives the most reliable adhesion without the part fusing to the plate.
On unheated glass or acrylic beds, use a glue stick as a release layer. Expect occasional corner lift on larger parts without heat; a brim at 5 to 8 mm width solves most of it.
Why is my TPU under-extruding at the recommended temperature?
Under-extrusion on TPU is usually a speed or moisture issue before it is a temperature issue. Dry the spool first, drop print speed to 20 to 30 mm/s, then raise the nozzle 5 degrees if the gap is still there.
Also check that your extruder tension is not crushing the filament. A notched filament past the gear slips invisibly and reads as under-extrusion on the finished part.
Can you print TPU on a bowden extruder?
Yes, you can print TPU on a bowden extruder, but stick to 95A or harder, run slower (15 to 25 mm/s), and bump the nozzle 5 to 10 degrees above a direct-drive setup to overcome the longer filament path. Softer 85A spools will buckle inside the PTFE tube regardless of settings.
Shorter retracts (around 2 mm) and slower travel moves help too. Aggressive bowden retraction with soft TPU is one of the most common causes of mid-print clogs.
Closing
Dial in temperature once and the rest of the print settles down fast. Our standard workflow: dry the spool, run a 20-minute temperature tower, pick the cleanest band, and lock that number in for the rest of the spool.
If stringing or inconsistent flow keeps coming back no matter how you tune the nozzle, moisture is almost always the real cause. A dedicated dryer like the Sunlu FilaDryer E2 sits next to the printer, holds temperature while you print, and cuts the recurring wet-spool problem out of the shop entirely.