TPU filament is one of the most popular flexible filament choices. This article covers the basics and outlines some quick tips and good test prints to make printing with TPU a little easier.
Thermoplastic polyurethane (TPU) filament is a common elastic polymer, or elastomer, which can be used with any FDM 3D printer—granted that you have fine-tuned your settings. Though it is among the most popular flexible filament types, TPU is slightly more rigid than similar options, making it easier to extrude and use for high-durability applications. It is considered to have medium-strength and is able to withstand much higher compressive and tensile forces than PLA and ABS.
In this guide, we go over the basic profile settings for working with TPU, as well as recommended settings for specific brands. A few great test prints and models that work well with TPU are outlined to get you started.
Basic TPU Settings and Characteristics
- Nozzle temperature: 210–230 °C
- Recommended bed temperature: 20–60 °C
- Print speed: Around 30 mm/s (manufacturer-dependent)
- Abrasion resistance: Very high
- Strength: Medium
- Flexibility: Very high
- Durability: Very high
- Soluble: No
- Hygroscopic: Yes
- Food safe: No
- Fumes: Low
- Recommended extruder type: Direct drive or Bowden (requires calibration)
TPU-printed objects exhibit minimal warping and shrinkage. You do not need a heated bed for TPU prints, but it is highly recommended to ensure proper adhesion. Print temperature and print speed can vary notably depending on the manufacturer, so we cover some essential information from common TPU filament manufacturers below.
It is important to remember that TPU is hygroscopic, meaning that it absorbs moisture from the air. As such, it requires careful storage in a dry, sealed location to avoid filament damage. The lower printing speeds require to reduce stringing often mean that your prints will take quite a while with TPU, but the durability and flexibility of the resulting object is typically worth it.
To produce excellent prints without risking a jam, a direct drive extruder is recommended. A Bowden setup can also be used but doing so will require more fine-tuning. Before starting any large, lengthy, or complex prints, we always recommend print a few small test objects to tune your settings.
This article covers some technical specs of common TPU filaments to provide recommended profile settings. For the new hobbyist—or print maker who has never worked with TPU before—some of the commonly used terms may be unfamiliar. We have provided the descriptions below as a reference.
Density: Mass per unit of volume (typically g/cm3)
Hardness: Resistance to plastic deformation in terms of a material’s “Shore hardness value,” which is measured by numbers (typically 0–100) and letters (OO, A, D) (e.g., marshmallow: 10A, which is very soft; Lego block: 100A, which is hard; PVC pipe: 80D, which is extra hard)
Elastic modulus: Resistance to elastic deformation measured in megapascal pressure units (MPa) (for reference, rubber has a modulus of about 1 MPa and ABS plastic has a modulus of 1,000-3,000 MPa)
Tensile strength: Maximum pressure (MPa) before breaking under tension
Elongation at break: Maximum length at the break point measured as a percentage of normal length
Common TPU Filament Types, Specs, and Settings
NinjaTek NinjaFlex TPU Filament
We included two popular NinjaTek filaments to illustrate the settings differences required by different TPU filaments intended for different applications. Plus, NinjaTek TPU filaments are widely considered among the best on the market and are often recommended to new makers.
Cheetah TPU is designed for higher-speed printing while retaining excellent quality. Cheetah TPU can be used at print speeds up to 60 mm/s, which rivals common ABS settings. Cheetah TPU has a Shore hardness value of 95A, which allows for printing at higher speeds.
- Density: 1.22 g/cm3
- Shore hardness value: 95A
- Elastic modulus: 26.2 MPa
- Tensile strength: 39.0 MPa
- Elongation at break: 580%
- Nozzle temperature: 230–240 °C
- Bed temperature: Up to 40 °C
- Print speed: 30–45 mm/s
This filament does best at the higher end of the recommended nozzle temperatures for TPU filaments. Though higher print speeds can be reached with the Cheetah TPU, we recommend starting out lower to reduce the risk of problems with larger prints and only increasing the speed for lower complexity prints after running a test.
NinjaTek Armadillo is not flexible but exhibits the same essential characteristics as other TPU filaments, acting as a hard rubber alternative. It is a tough, abrasion-resistant, and rigid material that can be used as an alternative to PLA, ABS, and nylon filaments. This filament is best suited for printing high-wear parts such as gears, fasteners, and protective cases that will not bend but require the tensile strength TPU filaments have to offer.
Armadillo TPU has 84%, 60%, and 90% greater abrasion resistance than PLA, ABS, and nylon filaments, respectively. Armadillo is also highly chemically resistant to substances such as naphtha, petroleum, and Freon, which makes it an excellent material for printing objects used in workshops.
- Density: 1.18 g/cm3
- Shore hardness value: 75D (approximately 225A)
- Elastic modulus: 396.4 MPa
- Tensile strength: 47.6 MPa
- Elongation at break: 295%
- Nozzle temperature: 220–230 °C
- Bed temperature: Up to 45 °C
- Print speed: 40–60 mm/s
Owing to its much lower flexibility than other similar filaments, Armadillo TPU can be printed at much higher print speeds than common alternatives. Take care when cleaning up your print though—its high abrasion resistance means that it will be extremely difficult to sand down.
Although Polymaker’s TPU filaments are slightly more pricey than other options, they are widely known in the maker community to provide high-quality materials for printing flexible objects.
- Density: 1.20–1.24 g/cm3
- Shore hardness value: 95A
- Elastic modulus: 9.4 ± 0.3 MPa
- Tensile strength: 29.0 ± 2.8 MPa
- Elongation at break: 330.1 ± 14.9%
- Nozzle temperature: 210–230 °C
- Bed temperature: 25–60 °C
- Print speed: 20–40 mm/s
SainSmart TPU Filament
SainSmart provides affordable 3D printing goods that are still very high quality. SainSmart’s TPU filament is widely considered one of the best on the market. It produces very strong prints for its low hardness and high flexibility characteristics.
- Density: 1.3 g/cm3
- Shore hardness value: 92A, 95A
- Elastic modulus: Unknown
- Tensile strength: Unknown
- Elongation at break: Unknown
- Nozzle temperature: 195–230 °C
- Bed temperature: 40–60 °C
- Print speed: 15–30 mm/s
SainSmart does not have the fine details of their TPU (like the elongation at break) available, but you can judge its utility for your project by its density and Shore hardness value.
TPU is a maker-favorite for flexible 3D printing applications owing to its excellent bed adhesion, minimal warping, and high abrasion resistance. While getting started with flexible filaments can be tricky, this guide should help you determine the best starting settings for your particular TPU brand. Test prints are always recommended, but why not print out a few fun things with your new flexible filament too?
What should I print?
TPU filament is used to 3D print a wide variety of items that require a bit of flexibility while being long-wearing. If you do not need to make specialized workshop items, TPU is great for simple, everyday use items such as phone cases, rubber mats, and stress toys.
TPU is also widely used to make accessories for RC vehicles, such as tires and shock absorbers. DIYers love TPU for making custom flexible parts, casings, and even seals that can withstand impact and movement.
For a test print, try a geometric vase design to experience the full flexibility (or “squishiness”) of your material. You can find some TPU-specific test prints like this dual hexagonal ring to check your edges and consistency. Of course, you can return to the tried-and-true Benchy to test whether your settings are optimal for layers at different sizes with mild detail.
If, after you have run your tests and calibrated everything, you are looking for fun things to print with TPU, find or design a phone case model that fits your cell phone and try modifying it with cutouts or raised designs or even a built-in kickstand. You can also print thumbstick and trigger mods for your PlayStation or Xbox controller. TPU is great for 3D printing stress balls and similar toys. A 3D printed Voronoi ball can double as an eye-catching desk accessory and a way to stress-test your print settings.