How to print flexible filament or TPU Filaflex

Every day, we receive many inquiries and doubts related to topics such as, for example, which machine prints Filaflex 60A, why can't I print Filaflex 70A on my bowden-type printer, if my printer is compatible with TPU filament, why doesn't it extrude Filaflex 60A...

Due to all these types of inquiries and doubts, we have considered reorganizing all the knowledge and information that we have been publishing on our website, regarding the flexible filaments of the Filaflex range, in one place.

Therefore, we hope to be able to resolve any doubts that may arise through this page, and if not, we will be equally delighted for you to reach out to us through any of our contact channels so that our technical team can resolve them as soon as possible.

Let's get started!

What is the Shore hardness of a flexible filament or TPU filament?

TPU Filament

TPU Filament is a very generic term in the world of flexible filaments, especially for a specialized company with extensive experience in manufacturing this type of material like Recreus (let's keep in mind that within the TPU family we have numerous models of flexible filaments in the Filaflex range that differ in their elasticity or Shore Hardness: Filaflex 95A, Filaflex 82A, Filaflex 70A, Filaflex 60A...).

Many times we read or see that a certain printer is compatible with TPU filament, just like that. However, this is a very generic statement that doesn't actually provide any information about the specific TPU material. It means it is compatible with TPU, but what Shore Hardness?

Usually, when printer manufacturers say that a machine is compatible or can print TPU filament, they are referring to a Shore Hardness of 95A for that TPU filament or flexible filament. But of course! Let's not forget that TPU filament has a wide range and variety of elasticities, ranging from the most elastic or flexible, like Filaflex 60A, to the least elastic, and all of them are included in the same TPU filament category.

That's why the compatibility of a TPU filament with a 3D printer cannot be generalized by simply saying that it is compatible with TPU. The 3D printer should specifically indicate which Shore Hardness of TPU it is compatible with. It is just as inaccurate as, for example, saying that all mobile phones are compatible with all chargers. There are different types of connectors and voltages that must match for successful charging, and each device has its own specifications and requirements, just like TPU filaments and 3D printers, which will require specific characteristics for successful printing, depending on the TPU filament.

Shore Hardness

Therefore, when we talk about TPU filament or flexible filament, we must pay attention to the specific elasticity of that TPU filament, which is what we call 'Shore Hardness'.

For more information on this topic, click here.

Which printer prints TPU filament or flexible filament better?

The difference between direct extrusion and Bowden extrusion

When we print flexible filament or TPU filament with a 3D printer, we must consider the type of printer we are going to use to print that TPU filament, since not all printers print all materials, especially flexible filaments or TPU and their different Shore hardnesses.

To do this, we will have to pay attention to several details:

the pushing system that the printer has
the Shore hardness of the TPU filament we are going to print
the hotend of the printer itself