BASF Ultracur3D ST 7500 G

The Ultracur3D ST 7500 G resin belongs to the BASF portfolio of Tough (High Impact) resins and it was designed for LCD/DLP systems and 385-405 nm wavelengths (printer compatibility and recommended settings can be found in the Downloads section). The ST 7500 G resin is very fast and easy to print and clean, and it requires only short postcure time. The 3D printed parts demonstrate excellent surface quality and intricate details, high durability and toughness.

Compared to other materials in the BASF Tough product line, the ST 7500 G resin has slightly lower impact resistance than Ultracur3D ST 45 B but absorbs way less water. Compared to Ultracur ST 80 B, ST 7500 G has overal better mechanical performance and prints much faster. In comparison to an existing general purpose grey resins on the market, Ultracur ST 7500 G shows very similar performance with higher elongation at break but with slightly lower Young's modulus and HDT.

Image 1: Comparison of properties between ST 7500 G and other resins. Source: BASF.

Ultracur ST 7500 G is safe to use as it is TPO-free. TPO is a typical photoinitiator used in many commercial photopolymer resins but it could have safety concerns in some regions (as per recent EHS classification changes). Ultracur ST 7500 G is biocompatible by norm ISO 10993-5 available on request. Nevertheless, it should be remembered that the biocompatibility of the 3D printed parts should be assessed separately for each application by the user.

Image 2: A drone element 3D printed with the ST 7500 G resin. Source: BASF.

As far as chemical resistance, samples 3D printed with the Ultracur ST 7500 G resin were submitted to testing to determine their resistance to various hydrocarbons and cleaning chemicals (cooling fluid, multipurpose fat, engine oil, hydraulic oil, brake fluid, transmission oil, acetone, isopropanol). The weight and mechanical properties (E modulus, tensile strength and elongation at break) of the samples were tested after 30 minutes and after 7 days. Overall, the most prominent changes were observed in elongation at break, whereas the tensile strength and E modulus are relatively stable. The detailed results can be consulted in the Downloads section.

Image 3: Detailed models 3D printed with the ST 7500 G resin. Source: BASF.

Samples 3D printed with the ST 7500 G resin were also submitted to UV testing, i.e. ageing of the 3D printed materials under UV radiation and periodic water sprays to test their discoloration and mechanical properties. The 1000 hours of testing has shown no visual change or additional yellowing compared to the reference sample, the E modulus remained failrly stable but elongation at break reduced. The detailed results of the UV testing can be found in the Downloads section. It must be kept in mind that it remains the responsibility of the user to determine the suitability of all printed parts for their respective application.

The excellent surface quality and intricate details of parts printed with the BASF Ultracur ST 7500 G resin as well as low water uptake makes it perfectly suitable for applications like figurines, hobby models, functional prototyping or even outdoor use.