+ What is TPR?

TPR's or Thermoplastic Rubbers are a type of 3D printing material that combines the properties of both a plastic and a rubber.

Most rubbers are thermoset, meaning that they can only be heated and cooled once, irreversibly forming them into a certain shape. This would not make them great 3D printing materials as we could make rubber filaments, but the resulting filament could not be melted and reformed - not very useful for 3D printing.

This is where the plastic properties come in handy. By creating a polymer that contains both the properties of rubber (prized for its flexibility) and plastic (able to be melted and reformed again and again), our TPR results in a flexible material that is able to be 3D printed.

+ What is the difference between TPU and TPR?

TPU stands for Thermoplastic Polyurethane. In the 3D printing world, TPU and TPR are often used interchangeably but there are some slight and subtle differences.

TPR as it is currently available on the market today is marketed as the softer of the two with a Shore harness numbers close to 70A while TPU's are the firmer with a Shore hardness closer to 90A.

While the two materials are effectively different grades of the same material, to avoid confusion and in keeping with market convention, our Shore hardness 65A, flexible 3D printing material is sold as TPR.

+ Can my printer print TPR?

Maybe.

If your printer has a direct drive extruder configuration, then it will most likely be able to print TPR without issue.

If you printer has a Bowden setup, it is still possible, but your printer may require some additional upgrades to the feed gears and extruder systems to be able to print TPU. Often, this can be as simple as printing a new bracket for your extruder gear and trimming the Bowden tube to have a pointed end. For more information, see our TPR Filament Printing Guide below.

+ Is TPR safe to print

Yes, TPR is safe to 3D print but good ventilation is also key to your health as the operator of a 3D printer. While TPR generates far fewer Volatile Organic Compounds (VOC’s) than materials such as ABS and HIPS when being printed, it’s still important to ensure good ventilation of the room your printer is located in if you plan on being present in the room for long periods of time. If proper ventilation cannot be maintained without causing draughts and irregular airflows, consider working in another room while the printer is active. If you must be present in the room when the printer is in operation, you may consider using an air purifier such as a Zimpure to keep VOC’s within acceptable levels.

Our TPR is also ROHS compliant and free of phthalates. For more information, check out our ECO+ policy.

+ What is Shore hardness?

Shore Hardness is a measure of the hardness (and softness) of various materials. There are multiple scales used to measure this, such as 00, A and D.

For the purposes of plastics, rubbers and 3D printing filament, a Shore hardness A scale is used. Using the Shore hardness A scale, a score of 10A is roughly as soft as a gummy candy and 100A being as hard as a hard hat.

With a Shore hardness number of 65A, our TPR is medium hard and is as soft as the material used to make a car tyre.

+ How Flexible is Standard Print Co. TPR?

Very. Our TPR has an elongation at break value of >500%. This means that it can be stretched to over 5 times its original length without breaking.

+ How durable is Standard Print Co. TPR?

Very. Our TPR was able to resist >20,000 cycles of flexing in a lab environment without sustaining damage.

+ Is Standard Print Co. TPR available in 1.75mm diameter?

Yes. TPR 65A is availible in 1.75mm diameter here.