Formlabs is at the cutting edge of stereolithography, with their suite of resins being as expertly engineered as the hardware that prints them. Their latest resin is a reformulation of an existing one, High Temp v2.
High Temp v2 is an updated version of High Temp v1, reformulated to be stronger and less brittle. The original High Temp Resin was launched October 2016 alongside Durable and Tough as an engineering resin with an extremely high heat deflection temperature at 0.45MPa of 289 °C. High Temp v2 has a lower heat deflection temperature of 238 °C @ 0.45 MPa but more elongation, and is much less brittle as a result.
Comparing the original High Temp Resin with the new version, we can see the new version has better impact strength. This is the most relevant spec for brittleness and means you can have confidence in parts not to shatter so easily.
Some users of the original High Temp Resin found the material too brittle for practical application, with parts and models cracking with stress. The new version is less brittle and because of this is far less prone to cracking. The lifetime of printed models is also higher as a result – a doubly good combination.
High Temp is suitable for prototyping, casting and thermoforming. Potential applications include manufacturing injection moulding tools and testing hot air and fluid flows. It still has the highest HDT among Formlabs resins making it the best choice for prototypes with high temperature resistance. Formlabs lists the following key applications: hot air, gas, and fluid flow; heat-resistant mounts, housings, and fixtures; and moulds and inserts.
If you’ll be printing with it, you can print Formlabs High Temp Resin at 100, 50, and 25 microns. It’s recommended that 25-microns is reserved for small objects that are the size of a piece of jewellery or smaller. It’s also important to note there is no difference in print quality between 25 and 50-microns, except 50-micron prints have a smoother surface. It means for most applications, 50-microns is just fine.
As with all of Formlabs’ resins, post-curing is required to create the chemical reaction necessary to strengthen prints and make them suitable for practical application. For this, you can use the Form Cure which uses 13 multi-directional UV LEDs and a rotating turntable to ensure complete UV penetration. If a thorough cure is not achieved, parts will not exhibit the high heat deflection temperature of 238 °C, which is what you want.
Lastly, it’s important to note that parts printed with High Temp Resin cannot be exposed to isopropyl alcohol (IPA) for longer than 10 minutes. If they are, they will begin to absorb the IPA. This will ruin parts to a point of no return. You can use the Form Wash for this since it has a timer and a viewing window so you can see your models.
You can find out more about the new High Temp Resin here. It comes in cartridge form, so is only compatible with the Form 2.