The Guide to Manufacturing Processes of TPU for 3D Printing
See why TPU is used for flexible, durable parts.
Thermoplastic Polyurethane (TPU) is a versatile and valuable material for producing flexible, durable parts.
Over the years, researchers have played a crucial role in developing and advancing both TPU and PLA, leading to significant improvements in 3D printing materials and revolutionizing additive manufacturing with more versatile and cost-effective options.
This complete guide provides engineers and designers with an in-depth understanding of TPU and how to successfully use it in 3D printing projects, highlighting how TPU is the answer to many flexible and durable part manufacturing challenges.
What is Thermoplastic Polyurethane (TPU)?
TPU is a flexible elastomer that falls between rubber and plastic in terms of its properties. TPU stands for thermoplastic urethane, a material known for its versatility in manufacturing.
It is a block copolymer composed of hard and soft segments, which give it a unique combination of flexibility and toughness. The chemical structure of TPU, with its hard segments providing strength and structural integrity and its soft segments contributing to flexibility and elasticity, is key to its performance.
Due to its durability and elasticity, TPU material can return to its original shape after deformation, making it suitable for wide-ranging applications across various industries, including automotive, aerospace, medical devices, sporting goods, textiles, and protective equipment. TPU is also widely used in fields such as sports, fashion, and wearable technologies to offer personalization options for brands.
TPU is commonly used in textiles and wearables, including medical supplies such as catheters, medical tubing, wound dressings, and wearable devices. Its flexibility and skin-safe properties make it ideal for wearables and medical applications.
In packaging, TPU is used for protective packaging, gaskets, and seals, but it is generally not recommended for food packaging or processing products due to risks like bacterial contamination and layer adhesion issues. Instead, its rubber-like qualities and abrasion resistance make it suitable for impact modifiers, anti-vibration products, and protective components.
After mentioning TPU’s flexibility and durability, it’s important to note that TPU is often used as an impact modifier for products like helmets, protective packaging, anti-vibration products, and gaskets or seals. It is also used for vibration dampers in automotive and aerospace testing, as well as for jigs in industrial processes like thermoforming uniquely shaped parts.
TPU can absorb moisture, which can negatively affect print quality, so proper storage and handling are important when using TPU in manufacturing processes.
TPU can be 3D printed using either Fused Deposition Modeling (FDM) or Selective Laser Sintering (SLS) technologies, which are the most common methods for 3D printing TPU. It is also advantageous for 3D printing, enabling the creation of customizable parts, rapid prototyping, and improving production efficiency while addressing design complexities. TPU filament provides excellent flexibility and durability, making it ideal for producing complex, bendable, and colorful components.
This material is commonly used with the Multi Jet Fusion manufacturing method. MJF uses fine powder and fusing agents to create parts with excellent detail and strength. It’s particularly suitable for producing TPU parts that require fine detail, good surface finish, and consistent mechanical properties.
Engineers and designers often choose TPU for its flexibility, ease of use, and ability to meet specific application requirements, though they also consider factors like finishing challenges, lack of rigidity, and moisture absorption when selecting this material.
| Property | Unit | Value | Norm |
|---|---|---|---|
| THERMAL PROPERTIES | |||
| Vicat Softening Temperature | °C | 84-96 | ISO 306 |
| MECHANICAL PROPERTIES | |||
| Tensile Strength | MPa | 7-9 | DIN 53504 |
| Tensile Modulus | MPa | 75-85 | ISO 527 |
| Charpy-Notched Impact Strength | kJ/m² | No break | ISO 179-1 |
| Flexural Modulus | MPa | 75 | ISO 178 |
| Shore – Hardness | A | 88-90 | ISO 7619-1 |
| Elongation at Break | % | 150-280 | DIN 53504 |
| PHYSICAL PROPERTIES | |||
| Density | g/cm³ | 1.10 | – |
| TOLERANCES | |||
| Achievable Part Accuracy | +/- 1.5 mm for parts up to 100 mm, +/- 2% for parts beyond 100 mm | ||
| Min. Wall Thickness | mm | 1.0 | – |
TPU Properties and Characteristics
Thermoplastic polyurethane (TPU) is a versatile material that combines the benefits of both plastics and rubbers. It offers a unique set of properties and characteristics that make it suitable for a wide range of applications, and is often selected for its desired properties depending on the end-use requirements. Some of the key properties and characteristics of TPU include:
High Durability and Flexibility: TPU is renowned for its ability to withstand harsh environments and maintain its shape and structural integrity over time. It also offers excellent impact resistance, making it an ideal choice for applications that require a durable material.
Chemical Resistance: TPU exhibits excellent resistance to a wide range of chemicals, including oils, greases, and solvents. This property makes it suitable for use in environments where exposure to chemicals is common.
Abrasion Resistance: TPU is highly resistant to abrasion and wear, offering excellent abrasion resistance, which makes it perfect for applications where friction and wear are a concern, such as conveyor belts and shoe soles.
High Tensile Strength: With its high tensile strength, TPU is suitable for applications that require strong and durable materials. This property is particularly valuable in the automotive industry for components that need to withstand significant stress.
Elasticity: TPU is a flexible material that can be stretched and deformed without losing its shape or structural integrity. This elasticity, combined with its soft touch and rubber like qualities, makes it ideal for products that require flexibility, such as protective phone cases and flexible joints in robotics.
Resistance to UV Radiation: TPU’s resistance to UV radiation makes it suitable for outdoor applications, ensuring that the material does not degrade when exposed to sunlight.
Thermal Properties: TPU demonstrates good thermal stability and heat resistance, allowing it to perform well in environments with elevated temperatures.
High Durability: Overall, TPU is a durable material that can withstand harsh environments and maintain its shape and structure over time, making it a reliable choice for various industrial and consumer applications across various applications.
Chemical Composition
TPU is a type of block copolymer consisting of alternating sequences of hard segments (isocyanates) and soft segments (reacted polyol). The formulation of TPU can be adjusted to include varying amounts of these hard and soft segments.
Materials with a higher proportion of hard segments tend to be firmer and more rigid, while those with more soft segments are more elastic and flexible. This unique combination of hard and soft segments gives TPU distinctive properties, including strength, thermal resistance, flexibility, and resilience.
The ability to tailor the chemical composition of TPU makes it a highly adaptable material for diverse applications.
Physical Properties
The physical properties of TPU are primarily determined by the ratio of hard and soft segments in its composition. One of the most critical characteristics of TPU is its hardness, measured on the Shore hardness scale, which indicates its resistance to indentation.
TPU also boasts impressive tensile strength, elongation at break, and abrasion resistance, making it an ideal material for applications that demand durability and flexibility. These properties ensure that TPU can perform reliably in various environments, from the soles of shoes to the intricate components of wearable technology. Additionally, TPU can be molded into various shapes to suit different applications, highlighting its adaptability for multiple industrial uses.
When designing 3D-printed TPU parts, it is important to maintain a minimum width of at least 1.5 mm to ensure proper detail visibility and structural integrity.
Start Your Manufacturing Project with MakerVerse
MakerVerse is a platform for sourcing industrial parts. It provides instant access to a vetted supply chain and a full range of manufacturing technologies. With AI-powered quoting, order management, and fulfilment, MakerVerse helps with everything from initial prototypes to full-scale production.
Types of TPU for 3D Printing
Several types of TPU are suitable for 3D printing, each with its unique properties and characteristics:
Polyester-Based TPU: Known for its high durability and resistance to abrasion and wear, polyester-based TPU is ideal for applications that require a tough and long-lasting material. It is commonly used in automotive parts and industrial applications where durability is paramount.
Polyether-Based TPU: This type of TPU is celebrated for its high flexibility and resistance to chemicals and solvents. Polyether-based TPU is perfect for applications that require a flexible material that can withstand exposure to harsh chemicals, such as tubing and seals.
Polyurethane-Based TPU: With its high tensile strength and resistance to abrasion and wear, polyurethane-based TPU is suitable for applications that demand strong and durable materials. It is often used in protective gear and footwear, where both strength and flexibility are required.
Hybrid TPU: Combining the benefits of different types of TPU, hybrid TPU offers a unique set of properties and characteristics. This type of TPU can be tailored to meet specific requirements, making it a versatile material for a wide range of applications.
Types of TPU for 3D Printing
Several types of TPU are suitable for 3D printing, each with its unique properties and characteristics. The evolution of 3D printing materials started with early liquids and powders, and researchers played a key role in developing advanced materials like TPU and PLA, which have significantly expanded the capabilities and applications of 3D printing:
Polyester-Based TPU: Known for its high durability and resistance to abrasion and wear, polyester-based TPU is ideal for applications that require a tough and long-lasting material. It is commonly used in automotive parts and industrial applications where durability is paramount.
Polyether-Based TPU: This type of TPU is celebrated for its high flexibility and resistance to chemicals and solvents. Polyether-based TPU is perfect for applications that require a flexible material that can withstand exposure to harsh chemicals, such as tubing and seals.
Polyurethane-Based TPU: With its high tensile strength and resistance to abrasion and wear, polyurethane-based TPU is suitable for applications that demand strong and durable materials. It is often used in protective gear and footwear, where both strength and flexibility are required.
Hybrid TPU: Combining the benefits of different types of TPU, hybrid TPU offers a unique set of properties and characteristics. This type of TPU can be tailored to support innovative design concepts and enable more functional applications, making it a versatile material for a wide range of uses.
When it comes to 3D printing TPU, SLS technology is better suited for higher throughput and more functional applications, making it ideal for industrial-scale production and demanding use cases.
In summary, advancements in new technology and the introduction of new materials have allowed for the production of highly specialized TPU components and TPU products. These innovations continue to drive the development of 3D printing, enabling greater customization, rapid prototyping, and expanded end-use applications.
Common TPU Applications with Abrasion Resistance
TPU is widely applied across various industries, including industrial components, consumer goods, and sporting goods, in addition to automotive, consumer electronics, medical devices, and footwear. OEMs leverage TPU and 3D printing technology for rapid prototyping and production of complex components in the automotive, aerospace, and medical fields, enabling faster and more cost-effective manufacturing.
Common applications include phone cases, seals, gaskets, shoe soles, flexible joints in robotics, and sports equipment. Its versatility makes it a popular choice for durable and flexible parts, especially for functional applications in industries like medical and automotive. In the context of automotive components, integrating advanced audio and visual systems can enhance both the functionality and aesthetic appeal of customized parts. Additionally, TPU is extensively used in consumer products such as athletic shoes and protective phone cases due to its durability and flexibility.
In-house 3D printing with TPU offers significant benefits, such as rapid prototyping, customization, and cost reduction, while reducing the need for outsourcing production tasks to external service providers. This in-house capability allows for faster iteration and greater control over design customization, particularly for complex, flexible parts.
TPU is used in both mass production and low volume production to meet evolving market demands, offering manufacturers the flexibility to produce large quantities or customized, small batches as needed. Design and material considerations are crucial for successful TPU applications, as attention to these details ensures optimal performance and helps overcome material limitations.
Some of the reasons it’s so popular include:
Flexibility and elasticity
High wear and abrasion resistance:
Chemical resistance
Good load-bearing capacity and impact strength
Stay on Schedule with MakerVerse
Unreliable lead times can disrupt your entire project. MakerVerse provides consistent delivery windows, real-time order tracking, and a dependable supply chain. From prototype to production, you stay in control and on time.
Troubleshooting Common TPU Printing Issues
Before starting a TPU print, it is important to properly prepare the 3D model and materials, ensuring everything is optimized and suitable for TPU filament.
TPU can be a challenging material to print with, and several common issues can arise during the printing process. Here are some of the most frequent problems and their solutions:
Warping: TPU can warp or deform during the printing process, especially if the print bed is not properly calibrated. To prevent warping, ensure that the print bed is level and heated to the appropriate temperature. Using a heated bed and applying an adhesive can also help keep the print in place.
Delamination: TPU can delaminate or separate from the print bed during the printing process, particularly if the print bed is not properly prepared. Achieving good adhesion is essential for successful TPU prints. To avoid delamination, make sure the print bed is clean and use a suitable adhesive or build surface to enhance adhesion. Monitor the first layers closely to ensure good adhesion and prevent print failures.
Stringing: TPU can string or ooze during the printing process, especially if the print head is not properly calibrated. To reduce stringing, adjust the retraction settings and print speed. Lowering the print temperature can also help minimize oozing.
Clogging: TPU can clog the print head or nozzle during the printing process, particularly if the print head is not properly maintained. To prevent clogging, regularly clean the nozzle and use high-quality TPU filament. Ensuring that the filament is dry and free from contaminants can also help maintain a smooth printing process.
Cooling: When 3D printing with TPU, it is important to reduce cooling to improve layer adhesion and print quality. Keeping cooling settings low helps prevent issues such as poor adhesion and warping.
Direct Drive Extruder: Using a direct drive extruder is preferred for printing TPU to maintain smooth filament flow and reduce the risk of jams.
Limited: 3D printing TPU parts can be limited by part size and technological constraints, depending on the printer and workflow used.
Anisotropic Properties: FDM printed TPU parts are anisotropic, meaning their strength varies across different axes, which should be considered in part design and application.
For those new to 3D printing, starting with an entry level workflow using affordable FDM/FFF printers is a cost effective way to begin working with TPU. By optimizing your printing process, you can reduce lead times for prototypes and custom parts, and achieve significant cost savings compared to traditional manufacturing methods.
Compared to traditional injection molding methods, 3D printing with TPU offers greater flexibility and lower costs for low-volume or customized parts, while injection molding is more suitable for high-volume production. 3D printing with TPU enables businesses to bring prototyping capacity under their own roof. Injection molding is a cost-effective way of producing parts in mass quantities, but it has limitations in terms of geometric flexibility or customization.
Post-Processing Techniques for TPU
Surface finishing: Techniques such as sanding, polishing, and tumbling can help achieve the desired surface smoothness. These processes are essential for improving aerodynamics and reducing friction in parts like drone bodies or automotive components. When working with parts produced using SLS technology, post-processing can also address intricate geometries, internal channels, and manifold type accordion structures, ensuring these complex features are clean and functional.
Painting and coating: Applying protective and aesthetic coatings enhances the durability and appearance of 3D-printed TPU parts. Coatings can also provide additional chemical resistance, including resistance to various chemicals such as oils and solvents, and UV protection, making them suitable for outdoor applications.
Heat treatment: Annealing and other heat treatments can improve the mechanical properties of TPU parts, such as increasing their strength and flexibility. Controlled heating can also reduce internal stresses and improve dimensional stability.
Machining and trimming: For applications requiring precise tolerances, additional machining and trimming may be necessary. This ensures that parts fit together correctly and meet specific design requirements.
Summary: Advanced post-processing techniques not only improve the quality and durability of TPU parts but also support higher throughput and the production of complex geometries, making them suitable for demanding and innovative applications.
Start Your Project with MakerVerse
D printing with TPU offers designers and engineers unparalleled flexibility and customization possibilities. From rapid prototyping to full-scale production, TPU’s unique properties make it an ideal material for a wide range of applications.
MakerVerse provides a comprehensive range of technologies and materials, including TPU, to support every stage of your manufacturing process.
Whether you need a single prototype or a large production run, MakerVerse offers the tools and expertise to bring your designs to life with industrial-grade quality and precision. For more information, please see our frequently asked questions.
