Back in October last year, Formlabs announced three new engineering resins for the Form 2: High-Temp, Tough and Durable. At the time, it was announced that Durable Resin would be available to purchase from January 2017 and Formlabs stuck to their word, announcing availability on January 31st. Formlabs published a useful article about Durable Resin to coincide with availability, but for those of you who are unfamiliar with polypropylene (PP) plastic and its uses, we thought we’d go one-step further with an article of our own looking at Durable Resin with a little more detail.
What is it?
Durable Resin is an engineering resin that simulates polypropylene (PP) plastic, a material that is traditionally processed in injection moulding or through CNC machining, for a wide variety of applications.
Polypropylene plastic can’t be extruded by a 3D printer consistently, so Formlabs had to create a new engineering resin that simulates it. Durable Resin is the result, and it has the same desirable properties of PP (it bends without breaking, and it is smooth and glossy with a frosted appearance).
Typical applications for polypropylene plastic include prototyping consumer goods, and creating snap-fit parts and joints. However, this plastic is perhaps best-known for its use in packaging and containers. Durable Resin is Formlabs’ most impact resistant material, so this is the material recommended for manufacturing low-friction and low-wear moving parts.
What is it for?
Durable Resin is ideal for prototyping products that will eventually be manufactured from polypropylene. Durable Resin is not designed to be a polypropylene replacement, although thanks to its similar properties, it can be used to create end-use parts that function similarly to polypropylene.
Because it’s strong and flexible, Durable Resin can be used to manufacture impact-resistant cases and housings, snap fits, ball joints, and parts that need to deform without breaking or snapping.
Appearance and Properties
When Formlabs announced Durable Resin last October, it was yellow. That colour made it stand out, but it also limited its potential use. Thankfully, Formlabs reformulated the resin and removed the yellow component of it, to create a resin that prints ‘frosted clear’ and smooth. The material is translucent, so it allows light, but not detailed shapes, to pass through. Of course, the thinner you print it, then the more transparent it becomes.
Here’s an image comparing the pre-production resin to the production resin:
As you can see, there’s a big difference.
In terms of properties, Durable Resin is Formlabs’ most impact-resistant material, with high elongation. Post-cured, Durable Resin has the following tensile properties: Strength at Yield: 31.8 MPa – Modulus: 1.26 Mpa – Elongation: 49 per cent. The Flexural Stress at 5 per cent strain is 27.2 MPa. The Heat Deflection Temperature post-cured is 43.3 °C.
Translating these properties for those of you who don’t know what they mean, basically Durable Resin will bend without breaking and deform several times without snapping.
Durable Resin requires UV post-curing with a suitable wavelength – Formlabs recommends 2.5 mW/cm² of 405 nm LED light for 120 minutes at 60°C. In terms of resolution, Durable Resin supports print resolutions of 100 and 50-microns.
Compatibility and Availability
Durable Resin is supported by the Form 2 3D printer only, hence why it is only supplied as a cartridge (the Form 1+ uses bottled resin). You can purchase your Durable Resin from us – we are an authorised Formlabs retailer. Here’s the product page where you can find out more about it.