Stratasys printers offer a wide range of material options across their FDM product line. These materials are all true thermoplastics that are common to many traditional forms of fabrication (i.e. ABS, PC, Nylon, Ultem). The majority of FDM printed parts are used for prototyping, jig, fixtures, tooling and end-use applications. In these settings, it's common for the 3D printed parts to come in contact with various chemicals. This means when deciding which material is the best fit for an application it's important to not just look at the strength of a particular material (tensile strength, impact-resistance, elongation at break, etc.), but we must also look at how a material can hold up to potential chemical exposure.
Application Driven Material Selections
As mentioned, chemical resistance is a key element when selecting the right material for a specific application. If a 3D printed part is going to encounter any sort of chemical, it's essential to know how that chemical with react with the materials and keep that as your first priority. While a material may exhibit great performance by the numbers or even in short-term testing - if the material is exposed to an incompatible chemical it can quickly deteriorate and fail.
For example, an automotive racing team may print aerodynamic body components using Ultem 9085. This material is a great solution for high impact, lightweight aerodynamic features on the automobile; however, if they are printing components for the braking system, Ultem 9085 would be a poor choice. Even though Ultem 9085 meets the necessary strength requirements for this use, it would rapidly deteriorate when exposed to incompatible chemicals; in this case, brake fluid. This is an instance where a different material, one that is more compatible with brake fluid, should be considered for the application. Nylon 12 has a superior resistance against brake fluid and would be better suited for this application. Initially the Nylon family would probably have been overlooked because it's less rigid than Ultem 9085; however, after you factor in chemical exposure, Ultem 9084 will break down and fail long before Nylon 12.
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.
While a simple guideline for FDM printed materials is listed below, it's important to understand that there are likely many variables in a real-world situation that must be considered. Things such as environmental temperature, pressure, UV exposure and print settings all can attribute to how an individual part will react with chemical exposure. For this reason, it is always advised to test critical components thoroughly before using them in critical applications.
Download our data sheet to get the details on all your favorite FDM materials.