What is the difference between TPE and TPU Flexible Filament?

Open your world, print flexible stuff like this airless tire concept.


You want to start using 3D printer flexible filaments? But with all the choice out there, it can be a bit daunting deciding which one to go for. TPE and TPU are both popular flexible, rubber like filament. There are other filaments like Flexible or Soft PLA, but the two serious players (TPU and TPE) in the market are harder wearing and more elastic – so they’re suitable for a much greater range of uses.

Why can’t I use actual rubber 3D printer filament? Well, rubber itself in a thermoset form cannot actually be re-melted due to the cross-linking that occurs in the original setting process. In short, we could make the filament – but you wouldn’t be able to re melt it to print with it.  

So you want all the end-use properties of rubber, like high elasticity, great compression strength and hard wearing durable flexibility – but in a form that’s easy to print? We hear you. Let’s delve into the key differences between these two thermoplastic elastomers so you can decide what’s right for your application.

First up, the original contender: What is TPE filament?

The full name, if you were interested is a ThermoPlastic Elastomer. Until recently, this has been the more commonly available material of choice for flexible printing (think Ninjaflex, SemiFlex, Filaflex and similar). It’s essentially a plastic that has rubber-like qualities.

Typically prints made with TPE flexible filament are really elastic – you can stretch them up to twice their original length and return to their original state, without permanent deformation.  It’s really soft, with a shore hardness of just 85A. Very soft flexible filaments have a history of causing difficulties in some printers when printing - depending on the type of extruder you’re using.  

While both materials we’re covering here have slightly different properties, here are the main similarities they share:

  • They’re generally regarded as safe and contain non-toxic raw materials.
  • Layer to layer adhesion is excellent, helped by their make-up and very soft nature of the printing. This means very durable end-use prints.
  • You can print both filaments at between 245C – 255C, with a heated bed around 90C
  • Printing at 15mm/sec speed is recommended, but you can print up to 30mm/sec with good results. This tends to be depending on your printer.
  • Both can be used to print objects that need to bend or flex to suit their environment, typically; belts, springs, door stoppers or phones cases.
  • The densities are near-identical at 1.20g/cm3 for NinjaFlex and similar TPE and 1.21g/cm3 for TPU.


Now, what’s this new TPU 3D Printer Filament?

Although technically classed under the ThermoPlastic Elastomer spectrum, the full name for TPU is ThermoPlastic Polyurethane. This isn’t especially new in industry, but until recently wasn’t commonly available in 3D printing. However recently it’s growing a lot more popularity among printers. While on the surface very similar to TPE, but TPU 3D printing has some notable differences.

TPU is very similar in elasticity and other mechanical properties to TPE. Although it is very slightly more rigid, at Shore 94A. This makes it a little easier to print in printers that don’t usually print TPE 3D printing filament well, as the slight more rigidity is easier for the extruder mechanism to handle. See our diagram below (you get the idea…)


Flexible Filament Extruder

Does this happen when using very soft filaments? Avoid it by using slightly more rigid filaments, like TPU or Flexible PLA. 


Sometimes this issue can be caused by simply having the wrong, or poorly designed flexible filament extruder. More extruders are being designed with this in mind. Still, as we say - if your extruder isn't working with your current flexi filament, try using a stiffer version and it should print fine. 

Apart from being a little easier to print, what are the other benefits? Well TPU material has a higher abrasion resistance, usually making it longer lasting in working parts. It also retains its elastic properties in lower temperatures – so if you need it to still be soft in cold conditions, it’s still going to perform.

Another notable difference is that TPU naturally has a higher resistance to oils, greases and a variety of solvents – making it more favorable in industry applications.

Shrinkage is usually hard to accurately measure, but for TPE it’s around 1.2 – 3.0 % and TPU has a lower shrinkage at around 0.8 – 1.8%. So if you need accurate measurements post-printing, you may be better with TPU. If you wanted to get really technical on TPU materials, here's the Wiki.

So there you have it, all the main differences between these ThermoPlastic Elastomers. Which you decide to print with will depend on your application. Below is a handy table to make a quick direct comparison. If you want to view our range of high-grade flexible TPU filament 1.75, feel free to browse them here.

Or if you're interested in our easy-to-print, biodegradable Flexible PLA, you can view it here. Due to it's slightly more rigid nature and low friction (meaning it won't stick in the bowden tube) our 2.85mm version is a great Ultimaker 2 flexible filament. 


Shore A Hardness:


Print temps:

Chemical Resistance:

Abrasion Resistance:



85A (very soft)


245-255C HB~90C



1.2 – 3.0%


94A (pretty soft)


245-255C HB~90C



0.8 – 1.8%

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