3D printing offers great possibilities and many varieties when it comes to printing flexible and rubber-like materials. From production parts to innovative and cool projects for hobbyists, this is something to check out. Let us take a look at the options of flexible polymers for 3D printing for the technologies available at Xometry. Shore hardness indicators of different 3D Printing materials When it comes to flexible polymers, Shore hardness is one of the main properties to look out for. The Shore hardness scales were created to provide a common reference point when comparing different materials. It is measured using a durometer gauge. There are different Shore hardness scales for measuring the hardness of different materials. The Shore OO Scale measures extremely soft materials like gels (e.g. gel insoles). The Shore A Scale measures a wide range of material types; from very soft and flexible to semi-rigid plastics with almost no flexibility at all. The Shore D Scale measures very hard rubbers, semi-rigid and rigid plastics (e.g. PVC pipe). Shore hardness comparison of different flexible 3D printing options As you can see from the image, there is overlap on the different scales. For example a material with a Shore hardness of 95A is also a Shore 50D. Flexible polymers available at Xometry: Different printing technologies require different polymers or resins to print. Let us see what print material each technology requires and their properties in detail Thermoplastic polyurethane (TPU) TPUs belong to Thermoplastic Elastomers category. TPEs can range from 10 Shore 00 up to 72 Shore D, spanning all three hardness scales, however, the most commonly used is the Shore A scale. TPU Polyurethane 88\/95A Commonly known as Ultrasint\u2122 TPU01 is a multi-purpose material for application exclusively in Multi Jet Fusion (MJF). This material is a thermoplastic urethane, with flexibility, high tear strength and offers good details. TPU 3D printing offers unique possibilities that are otherwise tough to achieve with other 3D printing materials like ABS, PLA or Nylon. Combining the properties of both plastic and rubber, TPU can produce elastic, highly durable parts that can be easily bent or compressed. The material exhibits stiff rubber-like qualities \u2013 much like a skateboard wheel \u2013 allowing for a range of end-use applications. In addition, the material is easy to print, and has good UV and hydrolysis resistance. Take a look at this spec sheet for detailed properties TPU MJF 3D printed parts \u2013 Xometry Technology: Multi Jet Fusion (MJF) Flex TPU\/TPE like If you require a resistant, flexible and rubbery material, Flexible TPU\/TPE for Selective laser sintering (SLS) is the perfect option. With a good resilience after deformation and a high Ultra violet (UV) stability, this elastomeric SLS TPU offers many advantages. By creating an interesting structural design, parts can be 3D printed for various applications, from automotive to footwear industries. The material gives a smooth white surface and also offers good hydrolysis resistance, great shock absorption. Technology: Selective laser sintering (SLS) TPU materials can be also used with FDM printing, but usually such 3D prints are of lower quality than when printed using the powder-based technologies like SLS or MJF, moreover, they almost don\u2019t differ in price. Properties of TPU There a few exclusive key properties of TPUs which benefits the industries Abrasion\/Scratch resistance High abrasion and scratch resistance means durability and high aesthetic value.TPUs give excellent results compare to other thermoplastic materials when abrasion and scratch resistance are critical for an application like automotive interior parts, sports and technical parts, UV Resistance Apart from maintaining good mechanical properties, they also show an extraordinary stability to ultraviolet radiation and thus superior color stability. For both light & dark color parts, industries can rely on TPU's high scratch resistance & UV performance as TPUs ensure colour fastness to the aesthetic parts. High flexibility TPUs offer high flexibility, shock absorption and rebound and are excellent choices for making footwear, sports equipment and orthopaedic models. This property is very helpful when it comes to automotive interiors and air filter covers. Other Advantages Good flexibility over a wide temperature rangeExcellent low-temperature and impact strengthRobust weather and high-energy radiation resistanceHigh elasticity across the entire hardness rangeResilience to oils, greases and numerous solvents Flexible CLIP resins CLIP resins are a class of high quality resins used with Carbon DLS 3D printing technology. At Xometry, we offer three types of flexible CLIP resins. Check out our video overview to see how they look like: DLS EPU 40 (1:22)DLS FPU 50 (2:36)DLS SIL 30 (3:36) https:\/\/youtu.be\/OZk7V1xi_Y4 DLS EPU 40 (Elastomeric Polyurethane): EPU 40 is a high-performance polyurethane elastomer that is a good choice for applications where high elasticity and tear resistance are needed. Elastomeric Polyurethane CLIP Resin, due to its high performance allows excellent elastic behavior under cyclic tensile and compressive loads. You can stretch it and bend it, it takes back its original printed shape. EPU 40 is comparable to commercial TPUs with a Shore hardness of 70A. EPU resin is rubbery, resistant, flexible and stretchable, with a layer thickness of 100 \u00b5m or 0.1 mm which are almost invisible. Parts are then very close to injection moulded models, which makes it very interesting for prototyping. Take a look at the spec sheet. Key Features Highly elasticTear resistantChemical and bio compatibility Applications Gaskets and sealsShock absorbersVibration isolators DLS FPU 50 (Flexible Polyurethane) FPU 50 is an impact, abrasion and fatigue resistant semi-rigid material that is a good choice for parts that must withstand repetitive stresses. This material can be ideal for tough enclosures, hinging mechanisms, and friction fits. FPU is comparable to polypropylene for its excellent fatigue and heat resistance. Features as thin as 0.25 mm can be 3D printed and it is not rubbery and elastic like EPU 40. Click here for the overall specs of DLS FPU 50. Key Features Tough and fatigue resistantHigh tensile strengthHigh impact and yield strength Applications Snap fitsStrain reliefs Mounts and brackets to encapsulate small electric circuits DLS SIL 30 (Silicone) SIL, a silicon-urethane material is comparable to commercial TPEs with a Shore A hardness of 35. CLIP technology enables 3D printing with novel classes of polymers, including complex chemistries such as polyurethane and cyanate ester-based resins. The result is a diverse and growing selection of materials reflecting common engineering requirements. Here is the spec sheet. Key Features Soft touchBio compatibleTear resistant Applications: Wearable (Wrist bands, headphone pads)Medical equipment All of these CLIP resins are suitable for long-term (>30 days) skin contact. Similarly, all can be used for short-term (<24 hours) mucosal contact except EPU 40*, which is suitable for skin contact only. Hence, they find their way into printing safe materials in the medical industry as well. Flexible polymers cost comparison Let's have a cost comparison of the three resins from Xometry\u2019s quote engine for the CAD model MaterialCost per one unitUnit cost per 10 piecesUnit cost per 100 piecesTPU Polyurethane 88\/95A(MJF)29.95\u20ac12.37\u20ac11.41\u20acFlex TPU\/TPE like(SLS)25.84\u20ac23.24\u20ac21.41\u20acEPU 40212.44\u20ac48.82\u20ac48.82\u20acFPU 50436.53\u20ac100.31\u20ac100.31\u20acSIL 30632.56\u20ac159.24\u20ac159.24\u20ac Conclusion There are 2 main types of flexible polymers for 3D printing available on the mass market: TPUs, which can be printed with FDM, MJF and SLS 3D printers and CLIP resins (Carbon DLS). Go with the TPU materials if you\u2019re looking for more affordable parts and with the more expensive CLIP resins if you require advanced material properties like high strength or tear resistance. All these 3D printing options are available at Xometry, just upload your CAD files and check out the price options.