Flexible, rubbery materials

TPU from SLS 3D printing: flexible components according to your needs

Whether technical damping elements, flex hoses, handles or keypads, TPU and flexible, rubber-like materials can be used for a wide variety of applications. If the material is processed with the 3D printing technology SLS (or FDM), diverse new possibilities arise.

TPU 3D-Druck mit Lattice-Struktur
SLS TPU 3D-Druck Bauteil knickbar

TPU, also known as thermoplastic polyurethane, is an elastomer plastic that has high flexibility and resistance to greases and oils. In additive manufacturing, TPU has many applications, from shoe soles and tires to custom building components and cell phone covers. It is particularly well suited for 3D printing end products, functional prototypes and design models. In this blog post, you will learn what to consider when 3D printing with TPU, what advantages the flexible material offers in additive manufacturing and in which application areas TPU can show its advantages particularly well. We also provide valuable design tips and weigh up the cost-benefit factor. The focus of this article is on SLS printing technology, since TPU poses great challenges for the printing process and lattice structures made of TPU material cannot be imaged with FDM, for example (support structures, etc.).

TPU 3D Printing with SLS: What are the advantages?

3D Druck Material - TPU Technologie SLS - Jellypipe

In selective laser sintering (SLS), small polymer powder particles are sintered by a high-performance laser. This creates the desired component in a powder bed. In the field of additive manufacturing, SLS enables high productivity at low unit costs - especially in the areas of rapid prototyping, individual production from batch size one and small series. Some special advantages of the material:

  • TPU offers a Shore hardness of 55 to 75. Shore hardness is a measure of the hardness of plastics and is used in the 3D printing industry to compare the properties of different materials. Hardness is measured on a scale of 0 to 100, with higher values representing harder materials. With TPUs, the hardness is very finely and seamlessly adjustable: the more energy is introduced into the material to melt it, the harder the material becomes. TPU thus offers excellent material versatility from hard to soft.
  • TPU offers high recovery with low compression set - significantly better than comparable plastics. TPU returns to its original state almost 100% of the time.
  • Most TPUs can tolerate continuous thermal stresses of up to 80° Celsius, and up to 120° Celsius is possible for short periods. With special TPUs, even higher heat resistance up to 180° Celsius is possible.
  • TPUs are partially UV-resistant. If the material is exposed to strong sunlight, it discolors. However, influences on the mechanical properties are not to be expected.
  • TPUs offer an extremely high elongation at break of up to 500%. Elongation at break describes how far a component can be pulled until it cracks. TPU from SLS 3D printing almost reaches the values of injection-molded TPU parts, which offer an elongation at break of about 700 %.
  • Hydrolysis is no longer a problem with modern TPUs. After about 10 years, a hydrolysis effect is visible; in the short-term range, water and temperatures no longer play a role.
  • Flexible color design: additively manufactured components made of TPU can be colored in different ways. Black TPU is particularly interesting because it mimics the typical "rubber material." In general, virtually all colors are feasible, but light shades are somewhat more difficult to realize.

Technical properties of TPU materials from SLS and FDM

You can read the technical properties in detail on the material detail pages:

Why is SLS 3D printing more complex for TPU than for other materials?

selective laser sintering technology sls

Selective laser sintering (SLS) and the 3D printing of TPU - an excellent combination, but one that entails some special features. Above all, the special thermal behavior of TPU is relevant. SLS 3D printing with TPU requires adapted process parameters - and process control is challenging. The individual components must be spaced further apart in the build space than when printing PA12, for example. Attention must also be paid to the special features of the material after TPU 3D printing. Cooling the build space cake and de-powdering is more complex in order to be able to release the parts cleanly.

Mechanical smoothing of the surface is not possible with TPU. However, chemical smoothing is possible with specially adapted solvents and work processes. A very interesting option is that the surface can be sealed media-tight. This means that water can no longer seep into the printed component.

If the components are to be colored, this is preferably done by dip dyeing. In this process, the natural color of TPU is overdyed. Another ecological and sustainable property of TPU in SLS 3D printing is that the powder can be 100% reused, since it is not damaged in the thermal printing process. In practice, however, only an admixture of 10 to 15 % per print job takes place in order to keep the quality of the prints constant.

Design notes for TPU 3D printing

For 3D printing of TPU, comparable design guidelines apply as for the PA12 material. Apart from this, you should take the following special features into account in the design:

  • No support structures are necessary when 3D printing TPU using Selective Laser Sintering SLS.
  • Tubes, profiles and undercuts should be designed as generously as possible. When designing, always ensure that caked powder can be removed.
  • If the parts are to be chemically smoothed after 3D printing, "non-functional surfaces" and "visible surfaces" must be precisely defined. With chemical smoothing, there is always a support or attachment point, comparable to sprue points for injection molded parts. A hook can also be added in CAD, which is removed after printing (if necessary).
  • The wall thickness must be at least 1 mm. Although the laser focus is significantly lower with SLS, the processing of TPU requires at least 1 mm during the process. This is the only way to achieve the required stability of the component. A wall thickness below 1 mm is possible for series parts if technical possibilities have been determined in advance and adapted to the application.
  • The cyclic load capacity of TPU parts depends on the geometry and the actual load (buckling or pressing). In principle, however, TPU exhibits high fatigue strength.
  • Waterproofing and splash protection can be achieved by chemical smoothing. Depending on the sealing profile and sealing partner, components can also be made directly waterproof. If required, please send us an individual inquiry in the store.


For less complex shapes, FDM technology can be an alternative, as it is less expensive for TPU components. However, depending on the geometry, support structures are required for FDM 3D printing. These are required more often with TPU than with other materials, which severely limits the printability of TPU parts with FDM technology. If you have any questions about this, please send an "individual inquiry" to the Store.

Application examples of TPU 3D printing

Supplemented with lattice structures, highly interesting applications can be realized with TPU. The hardness of the printed components can be very finely adjusted via the geometry. For example, the foam-like Kelvin structure produces soft components with increased resistance to bending loads, while the octet structure, which is also foam-like, enables harder components that optimally withstand tensile loads. Typical applications of TPU from SLS 3D printing include:

  • Grips or shock guards for mountain bikes.
  • Bellows in small or medium quantities that are particularly resistant to oils and greases
  • Keyboards for control panels in plant and mechanical engineering
  • Machine feet
  • Tires for remote-controlled RC model cars
  • Flexible hoses with sealed surfaces for applications in the engine compartment
  • Technical damping elements in plant engineering - here small quantities and components that fit the application exactly are in demand
  • Sealing profiles
  • Individual orthoses in the field of orthopedics
  • Realization of design ideas in the fashion sector
  • Shoe soles that can be washed in the washing machine
  • All areas of application where optimum static friction is required.

Prices and economy of 3D printed parts

When it comes to the question of up to what quantity range TPU can be competitively 3D printed, we have to answer with a rule of thumb. This rule of thumb states that cost-effectiveness is strongly dependent on the size and complexity of the required component. In SLS, typical series have a volume of between 5,000 and 15,000 parts. For TPU, the quantities for economical 3D printing are somewhat lower.

When it comes to very large quantities, TPU 3D printing does not become as cost-effective as injection molding. The relevance of 3D printing of flexible materials such as TPU lies primarily in the complexity - and offers immense advantages whenever production using conventional methods is not possible. Or when small quantities cannot be produced economically using injection molding.

TPU FDM 3D-Druck Fahrradgriff

If smaller quantities of a TPU component with simple geometry (without lattice structures and the like) are to be produced, FDM technology is a cheaper alternative.

Image: the bicycle handle could easily be manufactured with FDM technology due to the simpler geometry.

If you have any questions about TPU 3D printing or other specialist topics, please do not hesitate to contact us. We are looking forward to your project.

Your Jellypipe

Read more?


Markus Grimm
Chief Virtual Printfactory

Newsletter subscription

Stay up to date with our newsletter.