Formlabs most impact resistant material, Durable Resin is also highly wear resistant, capable of extreme deformation before breaking, and has low friction compared to Standard and Tough Resin. Use Durable to prototype models that will eventually be made from polypropylene (PP) or high density polyethylene (HDPE). It is best used when these features are required in a room-temperature application.
Polypropylene is very commonly used in situations where high elongation, deformation, and/or impact resistance are required. Applications of polypropylene include items like toothbrushes, car bumpers, packaging, razors, and more.
Durable is ideal for engineering prototypes and has been developed to withstand high strain. Consider printing in Durable Resin for applications that require impact resistance for rugged prototyping and for models that feel or look like real polypropylene. Like Flexible Resin, Durable Resin also works for objects that require some flexibility. Unlike Flexible Resin, Durable is also useful when you need to maintain good rigidity.
- Parts requiring high impact strength
- Prototyping parts that will be made out of polypropylene or HDPE
- Parts that require a low-friction surface, like ball joints
- Parts that are both rigid and flexible
- Snap-fit parts and flexures
NOT SUITABLE FOR:
- Parts with very fine details
- Parts that will be used in elevated temperature environments
- Constant loading
Comparison with Other Materials
To understand the difference between Durable Resin (similar to PP) and Tough Resin (similar to ABS), it helps to understand two key values: Elongation and Impact Strength. Learn more about how different materials perform under testing.
Elongation (given as a percentage of the original length) measures the length a material can stretch based on the original size, before it breaks. For applications requiring snap fits, flexures, or compliant mechanisms, a high elongation percentage value means the material can stretch a long way (or stretch repeatedly) before failing.
The second significant value is impact strength (given as a force over area), and is tested by hitting a sample piece with a pendulum hammer. A high impact strength means the material can survive more force without breaking. Impact strength is critical in applications that require the object to stand up to stress in the field. For this reason, polypropylene is used in many high-impact areas, such as car bumpers, which can bounce back after receiving an impact - and that’s why Durable has its name.
|Durable Resin, Postcured||Polypropylene|
|Tensile Strength (MPa)||31.8||25 - 40|
|Tensile Modulus (GPa)||1.26||1 - 1.5|
|Elongation (%)||49||100 - 400|
|Flexural Modulus (GPa)||0.82||1 - 1.5|
|IZOD Impact Strength (J/m)||109||100 - 160|
|HDT @ 0.45 MPa (°C)||43.3||70 - 80|
To learn more about Durable Resin's properties, download the material data sheet.
Printing with Durable Resin
Durable Resin can only be printed on the Form 2, and is printable in 50 and 100 micron layer heights. When printing models with large cross sectional areas, use the default touchpoint size as a minimum. The default size will tear off easily and properly support most geometries. For small or delicate parts consider reducing the touchpoint size.
Durable is not ideal for printing with very fine features - tiny holes and gaps may be filled in and tiny wires and walls may not come out as well as other resins. If you have these details in your part, consider enlarging them if possible.
Durable Resin’s properties make it well suited for snap fits, press fits, or other features that require deformation of the final part. To aid in assembly, the part can be heated using a hairdryer or heat gun before placement. After cooling the fit will be strong and tight.
Wash your parts with isopropyl alcohol (IPA) as per our standard guidelines, which recommend 10 minutes with Form Wash or 20 minutes with a standard Finish Kit. Do not leave Durable parts in IPA for longer than 20 minutes total; excessive alcohol exposure affects the quality of the final part. To automate the washing process, Form Wash agitates the alcohol bath and removes parts from the bath after a set time.
To achieve a smooth finish, sand support blemishes using standard sanding techniques. Sanding parts made with Durable Resin may prove more difficult than other resins, due to the low-friction surface, so allocate more time for finishing than other resins, at least for the first time.
After soaking, it is critical to post-cure the printed Durable part in order to achieve the proper mechanical properties. Parts should be cured with a 405 nm wavelength light or with a fluorescent light, like a nail salon.
For the best results, use Form Cure's 405 nm wavelength light source at 60 °C for 120 minutes. Flip the part after one hour - halfway through the curing process - to make sure the entire object is cured. Refer to our detailed research on Post-Curing Prints for suggested lighting and temperature for post-curing.
Formlabs’ post-curing solution, Form Cure, uses both temperature and 405 nm light for a fast and highly effective post-cure. Form Cure is available now for pre-order. Full setting recommendations for Form Cure will be available before shipping, and additional settings will be published as new materials are announced. Shipping begins in September 2017.