Thermoplastic Polyurethane (TPU) is a popular flexible filament on the market. It’s made of the same material as TPE, which is flexible, durable, and resilient like rubber.
This item is also resistant to wear, lubricants, oil, chemical, and abrasion. It is resistant to extreme cold, so it does not shatter when frozen and does not bow.
TPU is often used to make flexible, lightweight materials with various applications.
- Adipic acid esters are used to make polyester-based TPU.
- Polyether-based TPU filaments manufactured from tetrahydrofuran ethers.
- Polycarbonate TPUs are composed of polycaprolactone, which is a thermoplastic polyurethane elastomer.
Shore hardness measures a material’s resistance to indentation while submerged.
Shore hardness is usually between 75D and 98A for TPU flexible filaments.
TPU is an excellent material for various applications, especially in the automobile sector, thanks to its features. Let’s address this in more depth below.
TPU filament is also more resistant to heat, making it ideal for insulated components. In addition, compared to TPE filament, it is simpler to print and retains the elastic qualities better at lower temperatures.
Unlike other stiffer thermoplastics, TPU has flexibility and conformity found in different materials. It has a high interlayer adhesion, and it does not delaminate or curl when you use the proper settings during printing.
This is a 3D printing filament with medium strength, but it can resist greater compressive and tensile forces than PLA or ABS.
TPU Filament Properties
It is a fantastic option for 3D printing projects requiring flexible material since it has some characteristics. Because of its rubber-like qualities, it’s highly durable.
If you’re searching for a flexible filament, rejoice because TPU is more straightforward to work with than TPE.
Here is a list of TPU characteristics.
- High impact strength
- Durability: Extremely High
- Flexibility: Excellent
- Medium-high chemical resistance
- High abrasion resistance
- Waterproofness: Medium
- Heat: The extruder heats up to 250 degrees Celsius.
- Heated beds: 20° – 60° C
- Minor warping
- Minimal Shrinkage:
- Insoluble
- Yes, it absorbs water from the atmosphere.
Pros
- Can be recycled
- Coloring ease
- Elasticity like that of a rubber
- Abrasion resistance
- Tactile characteristics that are pleasant
- Its simple to use compared to PTE
- A good bond layer
- Oil, grease, and solvent resistance
- Low-temperature and impact strength are excellent.
- Excellent flexibility across a wide temperature range
- Weather and high-energy radiation resistance
cons
- A poor bridge quality
- Blobs and strung-together strings are possible.
- It’s possible that this will not function well on Bowden extruders.
- Due to its flexibility, ABS is more difficult to print than other filament types.
TPU applications
TPU flexible filaments are used in various applications, including car wheels, panels, automobile instruments, power tools, sporting goods, medical devices, drive belts, shoes, inflatable boats, and sheet productions.
Besides TPU, other types of plastic can be utilised to make the following products:
- TPU rubber
- Golf discs
- Medical tubing
- TPU film
- Seals and gaskets
- TPU phone case
- Industrial parts
- Cable ties
- TPU shank
- cable sheathing
- Tool handles
- Calendering
- Spiral and pneumatic tubing
TPU Safety
Is TPU safe to use?
TPU is a biocompatible thermoplastic material used in many applications, including prosthetics. It is not toxic and may be safely utilised depending on various circumstances, especially to other polymers such as PLA.
Its filament is a multi-purpose material frequently used in many areas of life.
However, because of its isocyanates content, which is formed by PUR-based solutions and may cause irritation in the throat, eyes, and nose, it is also associated with several health and environmental issues.
It may also cause breathing problems and other health issues that lead to blindness, disabilities, or death.
If the compounds are correctly produced, there is no risk of poisoning since the hazardous components are rendered inactive or non-toxic when successfully linked together.
Tips for Successfully Using TPU 3D Printing
ABS, PLA, and others are among the most popular polymers currently used in 3D printing. If you’re seeking a flexible filament, TPU is one of the best materials. This is simple to operate, but you must configure it correctly to perform as expected.
Here is some TPU 3D printing advice.
Adjust the feed rate to suit your needs.
When 3D printing flexible filaments, it’s critical to maintain a consistent feeding speed. This filament has a lot of giving, and it isn’t easy to keep the printing speed constant. If the printing speed varies suddenly, the TPU filament can be uncontrollable.
In extreme cases, the high temperature can cause a jam. You may need to test a few settings before finding the best print speed. A speed of 35 mm/s is a decent place to start.
Place the prints at 0.1 millimetres to 0.2-millimeter layer height, and make sure they’re within that range. The fewer layers that must be built, the less plastic is required, and the lower the extruder feed rate.
Avoid Using Rafts and Use a Negative Tolerance
Negative tolerance is advised between the components. This will guarantee that the flexible members can bend freely over the other project without compressing.
When utilising a flexible filament like TPU, avoid using rafts since its base layers have a greater extrusion rate, which might cause difficulties.
Retraction Options must be optimised.
TPU is a type of thermoplastic polyurethane. It’s not sensitive to slow movements; however, it is vulnerable to fast ones like retractions since it is flexible and elastic. It’s critical to get the retraction settings just right so that you can 3D print successfully. When extruding, it’s best to start with a lower amount of retraction and work your way up as needed until the extruder no longer oozes (hot-end).
Reduce the distance to a minimum
Some people like using a direct drive extruder to create 3D printed flexible materials, while others prefer them. On the other hand, a Bowden extruder can achieve similar results when used with the proper parameters on a 3D printer. It’s critical for the filament line to stay straight and free of kinks and coils as it travels through the melt zone.
Spool’s Positioning
It makes a significant difference if you do a few modifications to the spool of the material when you want to 3D print TPU. The filament will be fed into the extruder drive wheel, which may unwind a tiny quantity of plastic in the process.
A TPU filament, on the other hand, is elastic, meaning it stretches when pulled. This may lead to under-extrusion. As a result, the spool must be placed above the printer for the filament to unwind and download, which will minimise any resistance.
