With so many material options across Stratasys’s line of 3D printers, careful consideration must be given when deciding which material to use for your specific application. We must look at more than just the strength of the material (tensile strength, impact-resistance, elongation at break, etc.), consideration must also be given to how the material will react if exposed to chemicals.
If your 3D printed part is going to be exposed to chemicals, it is essential to know what the outcome will be. A 3D printed part exposed to a non-compatible chemical could quickly degrade and fail. For example, in an automotive application, ULTEM 9085 could be a great choice for manufacturing fixturing due to its strength, excellent impact resistance, and heat resistance; however, if the part has the potential to come in contact with brake fluid, then ULTEM 9085 has the potential to degrade and fail.
Thermoplastics – the go to polymers
Traditionally FDM has been the heavy hitter in terms of performance polymers. Boosting engineering grade thermoplastics like Polycarbonates, Nylons, Ultem (PEI), and Antero (PEKK). Many of these materials have exceptional resistance to common chemicals like oils, greases, and fuel.
A look at the Stratasys FDM Materials Chemical Compatibility chart will show us that a better option could be Nylon 12 which has greater brake fluid resistance. The chart also shows that other options for automotive applications include Antero 800NA and Antero 840CN03, both of which have superior chemical resistance.
Chemical Resistance Ratings
1 = Excellent chemical resistance: The solvent is unlikely to degrade the thermoplastic during prolonged exposure and moderate environmental conditions (room temperature and normal atmospheric pressure).
2 = Good chemical resistance: The solvent is unlikely to degrade the thermoplastic during short-term exposure and moderate environmental conditions (room temperature and normal atmospheric pressure).
3 = Limited chemical resistance: The solvent will likely degrade the thermoplastic during short-term exposure.
4 = Poor resistance: The solvent will likely attack and aggressively degrade the thermoplastic when exposed.
Thermosets – a new face in performance polymers
In addition to FDM, Stratasys has recently expanded their thermoplastics offering with the release of the SAF H350. Selective Absorption Fusion, SAF, is the technology behind the H350 and is a form of powder bed fusion 3D printing. The H350 produces accurate, production-grade parts consistently. This is achieved with an infrared-absorbing fluid that helps fuse the polymer powder. The fluid is selectively placed to create the part shape. The printer’s fusing lamps then heat up the powder and selectively fuses where the fluid has been placed but leaves the neighboring powder unfused. The H350 uses PA11, also known as nylon 11. Nylon 11 has good chemical resistance to things like oils and fuels, gasoline, mineral spirits, and some alcohols. This makes the SAF H350 a great option for high volume end-use parts.
Historically, thermoset plastics, like those used on Stratasys PolyJet machines have the ability to produce parts with incredible detail and full color. They do not offer the best chemical resistance. While PolyJet is a great solution for high-definition CMF models, it does not offer the mechanical, chemical, or thermal benefits of thermoplastics. The same holds true for many stereolithography materials. Much like PolyJet, they can produce amazingly detailed and tightly toleranced parts; however, chemical resistance is limited.
These chemical shortcomings are not universally shared across all thermoset polymers, Stratasys’s new Origin One product line looks to turn this accepted trade-off on its head. The Origin One uses Programmable Photopolymerization (P3) technology, an evolution from DLP (Digital Light Processing), to precisely control light, temperature, and other conditions. The build tray moves along the z-axis as an advanced 4K UV light projector cures the photopolymer. If you want more information on the Origin One and P3 we have a blog post detailing just that. Stratasys is working with chemical manufacturers (Loctite, DSM, BASF) to offer a broad range of high-performance materials. With an available open material license, the material options available for the Origin One printer are extensive and growing. With so many options it is recommended to check the manufactures technical data sheet to find the material that best fits your application.
Proof is in the pudding
With so many unknowns for each specific application, the information provided in most spec sheets are intended to be a guideline. Conditions such as environmental temperature, pressure, UV exposure and print settings all can attribute to how an individual part will react with chemical exposure. It is advised to test crucial components carefully before using them in critical applications. If you want to do testing but aren’t ready to pull the trigger on purchasing a machine yet, TriMech offers 3D printing as a service.
This can allow you to quickly assess the material properties before investing in a Stratasys 3D printer. If you already have a Stratasys machine and looking for advice our team of Application Engineers can help you find the best solution.
Download our data sheet to get the details on all your favorite FDM materials.