Written by Abigail April 30, 2024
What is TPU filament?
Thermoplastic Polyurethane (TPU) filament is a versatile and durable material used in 3D printing. It is known for its flexibility, elasticity, and resistance to oils, greases, and abrasion. TPU is a type of thermoplastic elastomer (TPE) with added benefits that stem from its unique molecular structure, which provides a perfect balance between plastic and rubber.
TPU, unlike rigid materials, is a champion of flexibility. It can be stretched or compressed and will always return to its original shape. This unique property makes it a dream material for creating parts that need to absorb impacts or flex while maintaining their form.
The manufacturing process of TPU filament involves a unique combination of hard plastic segments and soft, elastic segments. The hard segments provide the material with strength and rigidity, while the soft segments contribute to its elasticity. When heated in a 3D printer, TPU becomes pliable, allowing it to be extruded and formed into the desired shape. As it cools, it retains the printed shape while preserving its flexible characteristics.
TPU’s versatility is further enhanced by its ability to bond well with other materials during the printing process, making it suitable for composite and multi-material prints. It’s also relatively easy to print with, although it requires specific printer settings due to its flexibility.
Image Source: ERYONE
Mechanical Properties of TPU Filament
● Elasticity and Flexibility: TPU’s most notable property is its high elasticity. It can be stretched to significant extents and still return to its original shape without permanent deformation, which is quantified by its high elongation at break, typically ranging from 200% to 600%.
● Tensile Strength: TPU filaments exhibit impressive tensile strength, which measures the resistance of the material to breaking under tension. It generally has a tensile strength value of around 25 to 50 MPa (MegaPascals), making it strong enough for parts that are subjected to constant stress.
● Abrasion Resistance: TPU is highly resistant to wear and tear, which is essential for parts that will be in contact with abrasive surfaces or materials. This property extends the lifespan of TPU-printed parts in demanding environments.
● Impact Resistance: The filament’s ability to absorb energy makes it excellent for applications requiring impact resistance. It can withstand shocks and repeated impacts without cracking or breaking.
● Hardness: The hardness of TPU can vary depending on the formulation, but it typically falls within the 60A to 90A range on the Shore A hardness scale. This range allows for a balance between flexibility and rigidity tailored to specific application needs.
● Thermal Properties: TPU maintains its properties across a wide temperature range. It has a good heat resistance, with a melting point around 225°C to 250°C. However, it’s also capable of withstanding low temperatures without becoming brittle.
● Chemical Resistance: TPU is resistant to many oils, greases, and various chemicals, making it suitable for industrial applications where chemical exposure is common.
Image Source: Markforged
TPU Filament Variants
● Standard TPU: This is the most commonly used variant, offering a good balance between flexibility and strength. It’s suitable for a wide range of applications, including protective cases, gaskets, and wearable items.
● Medical Grade TPU: Designed for biocompatibility, this variant is used in medical applications where flexibility and skin contact are required. It’s often used for medical devices, prosthetics, and orthopedic models.
● High-Temperature TPU: With enhanced thermal properties, this TPU can withstand higher temperatures without deforming. It’s ideal for parts that will be exposed to heat, such as under-the-hood automotive components or industrial machinery parts.
● Alloyed TPU: This type combines TPU with other materials, such as polycarbonate (PC), to create filaments with unique properties. Alloyed TPUs can offer increased stiffness, impact resistance, and improved thermal stability.
● Conductive TPU: Infused with conductive materials, this variant allows for the creation of flexible electronic components, antistatic jigs, or parts that require electromagnetic shielding.
● UV-Resistant TPU: This variant includes additives that protect the material from UV radiation, making it suitable for outdoor applications where sunlight exposure is a concern.
● Eco-Friendly TPU: Made from renewable resources or recycled materials, eco-friendly TPU aims to reduce the environmental impact of 3D printing while maintaining performance.
Printer Setting for TPU Filament
1. Extruder Temperature: TPU melts at a higher temperature than some other filaments. Set your extruder temperature between 220°C and 250°C. Start at the lower end and increase if you notice poor layer adhesion.
2. Bed Temperature: A heated bed helps with first-layer adhesion. Set the bed temperature to 50°C to 70°C. Use a bed adhesive or a glue stick if needed to prevent warping.
3. Print Speed: Slow and steady wins the race with TPU. Due to its flexibility, printing too fast can lead to issues. Aim for a print speed of 15-30 mm/s for detailed parts and up to 40 mm/s for less intricate objects.
4. Retraction: Retraction can be tricky with flexible filaments. Start with a low retraction distance of about 1-2 mm and a slow retraction speed to prevent the filament from clogging.
5. Layer Height: A layer height of 0.1-0.3 mm works well with TPU. Thinner layers may provide better detail but will increase print time.
6. Fan Speed: Cooling is essential, but too much can affect adhesion. Set the fan speed to 50% after the first few layers to ensure proper cooling without causing layer separation.
7. Nozzle Type: Use a 0.4 mm or larger nozzle to reduce the risk of clogging. Stainless steel or hardened steel nozzle can withstand the abrasion of filled TPUs better than brass.
8. Enclosure: While not mandatory, an enclosure can help maintain a consistent temperature around the print, reducing the chances of warping or layer separation.
Remember, these settings are starting points. TPU filaments from different manufacturers may have varying properties so that adjustments may be necessary. Always refer to the filament manufacturer’s recommendations and perform test prints to dial in the perfect settings for your specific filament and printer model.
Image Source: Raise3D
TPU Filament Pros and Cons
TPU Filament Advantages
● Flexibility and Elasticity: TPU’s ability to bend and stretch makes it ideal for parts that require flexibility, such as phone cases, wearable devices, and seals.
● Durability: It is resistant to impact, abrasion, and wear, which translates to long-lasting printed objects.
● Chemical Resistance: TPU stands up well against oils, greases, and various chemicals, making it suitable for industrial applications.
● Thermal Stability: With a high melting point, TPU can withstand temperatures that would deform other flexible filaments.
● Versatility: It can be used in a wide range of applications, from consumer products to industrial parts.
● Ease of Printing: Despite being flexible, TPU is easier to print with than some other flexible materials, especially when proper settings are used.
TPU Filament Disadvantages
● Printer Compatibility: Not all 3D printers can handle TPU, especially those without a direct drive extruder or those that cannot reach the required temperatures.
● Printing Speed: Due to its flexibility, TPU must be printed at slower speeds, which can significantly increase print times.
● Stringing and Oozing: TPU can be prone to stringing and oozing, requiring careful calibration of retraction settings.
● Cost: TPU is generally more expensive than more common filaments like PLA or ABS.
● Post-Processing: While TPU can be sanded or cut, its flexibility makes other post-processing techniques, like painting or gluing, more challenging.
TPU Filament Applications
TPU filament’s unique properties of flexibility, durability, and resistance to various environmental factors make it a highly versatile material in 3D printing. Here are some of the most common applications of TPU filament:
1. Protective Cases: TPU’s shock-absorbing qualities make it perfect for phone cases, tablet covers, and camera skins that need to withstand drops and impacts.
2. Wearable Devices: Its skin-safe nature and flexibility are ideal for wristbands, watch straps, and other wearable technology accessories.
3. Automotive Parts: TPU is used for car interior parts, such as air ducts and vibration dampers, due to its durability and resistance to oils and greases.
4. Medical Devices: The biocompatibility of certain TPU variants allows for their use in medical applications, including flexible tubing, catheters, and prosthetic covers.
5. Sports Equipment: TPU is used in sports gear such as mouthguards, swim fins, and water bottle holders, offering both comfort and resilience.
6. Industrial Seals and Gaskets: The material’s resistance to abrasion and chemicals makes it suitable for creating industrial seals, gaskets, and hoses that can endure harsh conditions.
7. Footwear: TPU’s flexibility and strength are beneficial for shoe soles, insoles, and other components that require a combination of comfort and wear resistance.
8. RC Vehicles: Remote-controlled vehicle enthusiasts often use TPU for tires, shock absorbers, and other parts that need to be both strong and flexible.
9. Custom Grips and Handles: Tools, sports equipment, and household items can benefit from custom TPU grips that provide comfort and non-slip properties.
10. Flexible Joints and Connectors: TPU is excellent for printing parts that need to bend or flex while maintaining a connection, such as bellows and flexible couplings.
Best TPU Filaments of 2024
1. EOLAS PRINTS TPU Filaments
Eolas Prints’ TPU Filament promises to bring your designs to life with its exceptional flexibility and strength. The TPU Filament from Eolas Prints stands out with its impressive density of 1.21 g/cm³ and a Shore hardness of 93 A, ensuring that your prints will not only look spectacular but also withstand the test of time.
Image Source: EOLAS PRINTS
2. Bambu Lab TPU 95A HF
This innovative material is designed to revolutionize your printing experience, offering three times the speed of traditional TPU filaments without sacrificing quality. The TPU 95A HF filament boasts remarkable flexibility and toughness, coupled with outstanding impact resistance, making it an ideal choice for projects that demand durability and resilience.
Image Source: Bambu Lab
3. Raise3D Premium TPU-95A Filament
Raise3D’s TPU-95A is versatile and suitable for a wide array of uses, such as insoles, tubes, seals, and bushings. Its 1.75mm diameter and 1kg spool ensure that it fits seamlessly into your printing setup, supporting a variety of Raise3D printers.
Image Source: Raise3D
4. Filamatrix TPU 95A 3D Printing Filament
Filamatrix’s TPU 95A stands out for its ease of printing and speed. It allows you to achieve higher print speeds of up to 100 mm/s at 250 °C without compromising on the physical properties of your final product. Its wide processing temperature range and excellent layer-to-layer adhesion mean that even the most intricate designs will look sharp and durable.
Image Source: Filamatrix
5. Overture TPU 3D Printer Filament
Overture’s TPU Filament, thanks to its patented manufacturing process, is designed to ensure a clog-free and bubble-free printing experience. It promises a smooth and stable flow, with a dimensional accuracy of +/—0.03 mm and a 1 kg spool, making it compatible with most common 3D printers. The filament comes in a variety of colors, enabling you to choose the perfect shade for your project.
Image Source: Overture
6. Gizmo Dorks 3D Printing Flexible TPU Filament
Gizmo Dorks has crafted this TPU filament to be semi-transparent and highly elastic, making it resistant to oils and grease while maintaining ease of cleaning with just mild soap. It’s perfect for a variety of uses, from automotive parts to medical devices, and especially for protective cases for electronics due to its high flexibility. The filament ensures a smooth printing experience with technical specifications that include an extrusion temperature of 200 - 220°C and a heated bed plate temperature of 80 - 100°C. It’s recommended to print at a speed of 30 - 50 mm/s and a layer thickness above 0.1mm.
Image Source: Gizmo Dorks
7. MH Build Series TPU Flexible Filament
The MH Build Series TPU is celebrated for its affordability without compromising on quality. With a variety of colors available, your projects can now come to life in the most visually striking way. This filament is compatible with a wide range of printers and is especially suited for producing parts that need to withstand wear and tear. Whether you’re creating custom phone cases, wearable devices, or intricate models, the MH Build Series TPU ensures that your creations are impressive in appearance and performance. With bulk pricing options, the more you buy, the more you save, making it a smart choice for those who print frequently.
Image Source: MatterHackers
8. MH PRO Series TPU Filament
MatterHackers’ Black PRO Series TPU is a filament that embodies the perfect synergy of flexibility and durability. This 1.75mm thermoplastic polyurethane material is engineered for those who demand precision and performance in their prints. Whether you’re crafting custom-fit gaskets, belts, or prototypes for products like mouthguards and watch straps, the PRO Series TPU is your go-to filament for intricate and demanding print jobs. With a diameter tolerance of ±0.02mm, this filament ensures smooth and consistent extrusion, making it a reliable choice for both prototyping and end-use parts. Its rubber-like qualities provide the necessary energy return and fatigue resistance for parts that need to withstand repeated use.
Image Source: MatterHackers
9. HATCHBOX 95A TPU Filament
Hatchbox’s commitment to quality is evident in every aspect of this filament, from its elasticity strength to its abrasion resistance, ensuring that your prints can handle the wear and tear of everyday use. Whether you’re printing custom-fit phone cases, intricate wearable fashion, or robust mechanical parts, this filament provides the reliability and performance you need. It offers a seamless printing experience with a recommended extrusion temperature range of 190°C - 235°C.
Image Source: HATCHBOX
10. colorFabb VarioShore TPU
The filament’s active foaming technology allows it to expand to approximately 1.4-1.6 times its original volume, reducing its density to 0.7 to 0.9 g/cm³ when printed at temperatures between 200 and 250°C. This means you can print with lower flow rates to achieve incredibly soft parts or choose to print without foaming between 190 °C and 200 °C for harder prints. With colors turning lighter when the material is fully foamed, colorFabb VarioShore TPU filament provides a unique aesthetic dimension to your prints.
Image Source: colorFabb
